Dr Jay K. Varma

Blog

  • Could Raw Milk Spread Bird Flu? The Science Behind a Growing Risk

    Raw Milk Myths vs. Public Health Reality

    Raw milk has long been a favorite among wellness influencers and natural health advocates. Some claim it offers unique nutritional benefits that pasteurized milk lacks. But for infectious disease and public health experts like myself, the risks are far greater than any supposed rewards. A CDC study once concluded, “Unpasteurized dairy products thus cause 840 (95% CrI 611–1,158) times more illnesses and 45 (95% CrI 34–59) times more hospitalizations than pasteurized products.”

    Bird Flu Hits Dairy Cows

    Now we have a new concern about raw milk beyond bacterial contamination: H5N1 bird flu.

    Let’s review what we know. Bird flu jumped into dairy cattle in the past year, a development that caught many of us by surprise. While the virus has traditionally been associated with poultry and wild birds, its appearance in milk-producing cows means the threat to both food safety and occupational health has expanded.

    Pasteurization vs. Raw Milk

    Recent studies have shown that, while pasteurized milk may contain trace amounts of viral particles, they are not infectious. The pasteurization process, which is designed specifically to kill harmful pathogens, does its job well. Pasteurized milk remains safe to drink.

    Raw milk contaminated with H5N1 influenza, however, is a different story.

    How Long Does H5N1 Survive in Raw Milk?

    Researchers recently conducted experiments to understand how long H5N1 remains infectious in raw milk. They spiked raw milk with live virus and stored it under two conditions: at room temperature and under refrigeration at 4°C. At room temperature, the virus decayed after about a day. But under refrigeration—how most people store milk at home—the virus remained viable for up to seven days.

    Occupational Exposure Risks

    Although we don’t yet have evidence that drinking raw milk contaminated with H5N1 causes human infection, we do know that the virus can enter the body through mucous membranes, including the eyes and respiratory tract. We also know that infectious virus surviving for a week in raw milk creates ample opportunities for exposure. That includes consumers and anyone handling milk once it leaves the cow: farm workers, processors, and anyone in close contact with splashes or spills.

    This is where public health intersects with occupational safety. Farm workers in milking parlors are often exposed to raw milk directly when it’s splashed on the face, hands, or eyes. If infectious virus is present, and if the person is not using adequate protective gear or hygiene protocols, there is a risk of infection.

    The Danger of “Natural” Myths

    What frustrates me is how easily this conversation gets distorted. Wellness influencers continue to romanticize raw milk as “natural” or “clean,” when in fact, it’s a high-risk product. Nature isn’t always safe. In this case, it may contain a virus with pandemic potential.

    This debate reminds me of similar moments during COVID-19 where emotion, anecdote, and ideology often drowned out science.

    What We Still Don’t Know

    There’s still a lot we don’t know about bird flu in cows. How exactly did the virus jump from birds to bovines? What is the risk of mutation as it crosses species? Could it eventually gain the ability to spread efficiently between humans?

    Final Recommendations

    While researchers are working to answer these questions, one fact is already clear: raw milk is a preventable risk.

    If you like drinking milk, please stick with pasteurized products. If you’re a policymaker, it’s time to revisit the patchwork of state laws that allow commercial raw milk sales in the U.S.

  • Planning a Trip to Hawaii? Here’s What You Should Know About Zika Virus

    Why Zika in Hawaii Matters

    Hawaii is one of the most beautiful places on Earth and one of the most desirable vacation destinations for Americans. I’ve only been once oer 20 years ago, but have amazing memories of the island of Kauai. So when health agencies report about the emergence of Zika virus there, the media cover it, even if the risk to the general public is low.

    What We Know About the Current Zika Case in Hawaii

    The recent Zika case reported in Hawaii was travel-associated. That means the person was infected with Zika somewhere else and then traveled to Hawaii. Importantly, there’s no evidence that the virus has been transmitted locally.

    But this type of event is exactly why we have surveillance systems. A doctor saw a patient with symptoms, ordered testing, and a public health agency investigated the results and determined where the infection likely occurred.

    How Zika Virus Spreads

    To understand why this matters, let’s review how mosquito-borne viruses like Zika get introduced into new places. There are two primary ways:

    • An infected person arrives in a place where the right kind of mosquito is present. If a mosquito bites that person, it can then transmit the virus to other people.
    • Infected mosquitoes themselves hitch a ride on airplanes, ships, or cargo, including infected animals that are being brought to Mexico.

    For a virus to remain established in a new place, it has to have the types of mosquitos that can transmit Zika. Hawaii’s tropical climate leads to a year-round mosquito season, including the types that can transmit Zika. Specifically, Aedes albopictus is widespread throughout the state, while Aedes aegypti has been found on the Big Island and Molokai. 

    Mosquito Control: Lessons from NYC

    Back in 2016, I helped lead New York City’s Zika response. One of the biggest takeaways from that experience? Mosquito control outside the home is all about standing water. People often think of ponds or birdbaths, but even something as small as a bottle cap or top lid of an aluminum can can be enough to breed mosquitoes. Public health campaigns focused on eliminating water-holding containers—flowerpots, gutters, outdoor toys—were critical. That same approach applies in Hawaii today.

    Hawaii and the Risk of Emerging Diseases

    Hawaii’s geography is both a strength and a vulnerability. Its distance from the mainland U.S. offers some protection. But its ecosystem is fragile, and its economy depends on tourism from all over the world. This makes it a potential landing spot for many emerging infections. Zika would be another example—not of panic, but of why early detection and mosquito control matter.

    Zika and Pregnancy Risks

    For most people, Zika causes either no symptoms or mild ones, including fever, joint pain, fatigue. But the danger comes with pregnancy. If a pregnant woman becomes infected, or is exposed through sexual transmission, Zika can lead to severe birth defects, most notably microcephaly—a condition where the baby’s brain doesn’t develop properly.

    This is why Zika remains a concern even when case numbers are low. Public health agencies recommend that pregnant women, or those trying to become pregnant, avoid travel to areas with Zika transmission. And if they do travel, strict mosquito precautions and sexual health guidance should be followed.

    Bottom Line

    Hawaii has not reported any local transmission of Zika virus. But the presence of a travel-associated case reminds us that surveillance works, mosquito control matters, and behavior change can avert death and disability. If you’re traveling to Hawaii—or anywhere with mosquitoes—cover up during the day, use insect repellent, and eliminate standing water around your home or lodging. And if you’re pregnant or planning pregnancy, talk to your healthcare provider before you go.

  • Ostriches, Outbreaks, and Outrage – An Odd Tale of Bird Flu

    Oz, Ostriches, and Outbreaks

    If you happened to see headlines recently about Dr. Oz, Canadian ostriches, and bird flu, you may have been as confused as I was. And, of course, tempted to click. This is, in fact, a real story and one that reveals how misinformation and political grandstanding are complicating infectious disease control in the Trump Administration.

    Avian Influenza in Ostriches

    Let’s start with the facts. A bird flu outbreak occurred on an ostrich farm in Canada. Some of the ostriches survived. Dr. Mehmet Oz, now head of the Centers for Medicare and Medicaid Services under the Trump administration, publicly called for those birds to be “rescued” and relocated to his ranch in Florida. One reason he wanted to save them is because he believes their survival might be useful for researchers to understand how to treat H5N1 infections.

    Ostriches, like other birds, are susceptible to avian influenza. In fact, we’ve seen H5N1 outbreaks in ostrich farms before, particularly in South Africa, where ostrich farming is a major industry. Symptoms can range from mild to severe, including neurological problems and death. The standard control strategy that is globally accepted by veterinary health authorities is to depopulate the farm. That means killing the remaining birds to prevent further spread.

    Why Depopulation Is Scientific Best Practice

    Why is this necessary? Because even birds that survive might still harbor the virus. They could be shedding it at low levels. They could appear healthy but remain infectious. And because ostriches are often raised in outdoor environments, they interact with wild birds, creating opportunities for the virus to spread back and forth.

    There’s no reliable way to determine on a farm whether an individual ostrich has truly cleared H5N1 infection. That’s something you can only assess in a controlled laboratory environment where birds are tested completely before they enter the laboratory, exposed to a standardized dose of H5N1 influenza in a standardized way, then monitored continuously for an extended period without any new exposure.

    Public Health Risks of Animal Movement

    Moving those birds from Canada to Florida risks the health of animals in the U.S. and potentially humans as well. Imagine if just one bird were still infectious. The result could be an outbreak on U.S. soil affecting other ostriches on Dr. Oz’s farm, and, because migratory birds can then get infected from these ostriches and spread the infection by air elsewhere, it also puts poultry farms, dairy farms, and other animals at risk.

    The Natural Immunity Fallacy

    This incident is part of a broader pattern. During COVID-19, many so-called contrarian voices argued that “natural immunity” was enough—that surviving infection meant you were safe and no longer a threat to others. Now, many of those same people have roles in the federal government. Their simplistic views of immunity ignore the complexity of viruses, immune responses, and transmission dynamics. They believe that because some ostriches survived H5N1 infection that their blood holds the key to understanding H5N1 immunity.

    Surviving infection doesn’t necessarily mean protection. Viruses mutate. Immunity wanes. And different hosts react in different ways. That’s why we rely on careful science, not gut instinct or political messaging, to guide public health decisions.

    Emotional Appeals vs. Science

    This case also mirrors past emotional appeals involving animals and disease control. During the 2014–2016 Ebola outbreak, a Spanish nurse’s dog was euthanized after she became infected. In the U.S., a nurse’s dog was quarantined and monitored. In both cases, public emotion clashed with public health logic.

    Ostriches are large, charismatic animals. That emotional appeal can cloud judgment. But when lives—human and animal—are at stake, emotion can’t override evidence.

    Where Are the Influenza Experts?

    What’s missing in this debate is the role of experts. We haven’t heard the USDA weigh in, despite its role as the leading authority on animal health in the U.S. Canadian officials made the decision to depopulate the farm, following standard protocols.

    And it’s worth noting: Dr. Oz hasn’t offered to “rescue” chickens from infected farms in the U.S. Ostriches, for some reason, have captured his fancy and clouded judgement about public health.

    Final Thoughts on H5N1 Influenza Risks

    Avian influenza is a serious and evolving global threat. We don’t yet know how this virus might mutate. But we do know that the risks are too great to play fast and loose with this virus. See my discussions about Germ Denial to understand this challenge: Germ Denial: Resources and Checklists

  • COVID Variant NV.1.81 – Should You Be Worried?

    What Is COVID Variant NV.1.81?

    It’s the first time in a long time that I have seen the media cover a new variant of COVID-19. If you’re wondering whether this new variant—labeled NV.1.81—should change your summer plans, the short answer is: not really. But it’s still worth understanding why public health experts are paying attention.

    How Do We Know It’s Spreading?

    Let’s start with several things we know about this variant so far. First, this new variant is an incremental evolution of the virus. It’s slightly more transmissible than recent versions, and it’s quickly becoming dominant in some regions.

    We estimate how easily a virus spreads from person to person by monitoring genetic sequences of the virus. Then, when a new strain emerges, we look at how quickly that strain becomes more common than older ones. NV.1.81 is rising in frequency—an early indicator of greater transmissibility.

    Does NV.1.81 Cause More Severe Illness?

    Fortunately, this variant doesn’t appear to cause more severe disease. The symptoms, hospitalizations, and outcomes are, so far, similar to what we’ve seen in the past year. Even better, vaccines continue to work well, particularly for people who are up to date with receiving booster doses.

    In that way, NV.1.81 is part of the same family of variants we’ve been living with since Omicron dramatically reshaped the pandemic in 2021.

    What We Know About COVID-19 in General

    Even before this variant emerged, we knew several things about COVID-19. The virus is now endemic, meaning it circulates in the population year-round, with occasional waves from season to season.

    Like the flu, COVID-19 infections reliably peak every winter. But unlike the flu, COVID-19 also causes two to three smaller peaks throughout the year. These are often driven by new variants, behavioral changes (such as returning to school), or both.

    How to Reduce Your Risk

    There are multiple ways to reduce your risk of getting COVID-19. While no method or even combination of methods is 100% effective, each layer of prevention adds protection.

    • Wear high-quality, well-fitting masks
    • Stay up to date on COVID-19 booster vaccines
    • Clean indoor air by improving ventilation or using air filters

    All of these help lower your chances of infection and the short- and long-term health consequences that come with it.

    So how should you think about NV.1.81? My advice is the same I’ve been giving for the past two years: stay informed, use precautions when cases rise in your community, and get up to date on vaccinations at your local pharmacy or primary care clinic—especially if you’re over 65, have a chronic health condition, or are immunocompromised.

    Why Vaccine Policy Is at Risk

    What concerns me more than the virus itself is how politicized vaccine guidance has become. The FDA is increasingly being pulled into debates about whether vaccines should be recommended for healthy people, children, and pregnant women.

    That’s not how our system is supposed to work. The FDA’s job is to determine whether a vaccine is safe and effective. It’s the role of the CDC and practicing clinicians to decide who should get it.

    The data are clear: vaccines are safe and effective for pregnant women. They remain one of the most powerful tools we have to prevent serious illness. I’ve had six or seven doses myself. But I worry that political interference will:

    • Confuse healthcare providers
    • Cause insurers to reduce vaccine coverage
    • Lead pharmacies to stop stocking vaccines due to perceived low demand

    Final Thoughts

    We’ve lost nearly 47,000 Americans to COVID-related illness in the past year. That number could be much lower with clear, consistent, science-based public health policy.

  • How Anti-Science Becomes Policy: A Deep Dive with Dr. Tom Farley

    Table of Contents

    Introduction

    On my Thermometer YouTube series, I recently sat down with Dr. Tom Farley—former Health Commissioner of New York City and Philadelphia—to discuss a disturbing new shift in U.S. public health policy. Under the Trump administration’s new “Make America Healthy Again” (MAHA) initiative, health decisions are being shaped by ideology rather than by evidence.

    In this in-depth interview, we dissect how pseudoscience is gaining ground in government policy and why it matters to anyone who cares about facts, health, and the future of science.

    The “Make America Healthy Again” Report

    The MAHA Commission was formed under executive order to examine rising rates of chronic disease among children. Instead of reviewing the best available epidemiologic data and evidence, the report is framed around a nostalgic, fact-free vision of a time when “America was healthier.” It’s a vision based far more on political messaging than public health evidence. As Tom noted, the report appears to be rooted in the personal beliefs of RFK Jr., including unsupported claims about childhood disease rates and dubious concerns about vaccines.

    From Fact to Fiction: Misinformation in the Report

    The report starts by redefining chronic disease in an unscientific way. It lumps together conditions like asthma, autism, ADHD, allergies, and obesity as if they share common causes and solutions.

    The report does address some important public health problems, particularly the rise in childhood obesity and type 2 diabetes. Both of these are well-documented to be increasing in children and largely driven by ultra-processed (or “junk”) foods.

    But from there, the report gets weird. It blames mental illness in teens on food additives, links allergies to vaccines, and treats unsupported theories as settled science. It claims that 60% of kids have chronic illness today compared to 6% in the past, without any legitimate data to support that number. As Tom and I discussed, it’s a blend of half-truths, misinterpretations, and outright lies.

    The Rise of Pseudoscience in Health Policy

    The MAHA report outright fabricates information. Some references lead to journals that lack peer review, which basically means someone typed some text in a word processing software, turned it into a PDF, emailed it to the journal with a check, and had it published. That’s not the way high-quality scientific journals work, and those “studies” have no scientific value.

    Other references in the report cite studies that simply don’t exist. This is not some minor low-level report. This is the signature health policy report of a presidential administration. If a high school student submitted this for their term paper, they’d like be given an “F” and subjected to a disciplinary hearing.

    This kind of pseudoscience is particularly dangerous because it masquerades as legitimate science. It borrows the language of evidence-based medicine to argue against it—claiming, for example, that vaccines haven’t been tested properly, when in fact, COVID vaccines went through large randomized controlled trials and real-world surveillance.

    The goal is to sow doubt, and then for MAHA supporters to sell supplements and alternative therapies as part of an ideological worldview that discredits science altogether.

    COVID Vaccination in Pregnancy: Science vs. Politics

    Perhaps the clearest example of how anti-science ideology is reshaping public health came in May 2025, when the U.S. dropped its recommendation for COVID vaccination in pregnancy.

    Let’s be clear. Data from the U.S. and globally show that COVID infection in pregnancy increases risk for preterm birth, preeclampsia, ICU admission, and death. And vaccination helps reduce those complications with no concerns about safety. The CDC originally recommended vaccination based on that evidence, which was and remains the right call.

    But in a video posted to X (formerly Twitter), RFK Jr., the FDA commissioner, and the NIH commissioner reversed course without any input from CDC experts or clinicians. The U.S. is now the only country in the world that doesn’t recognize pregnancy as a high-risk group for COVID. .

    When Scientific Review Is Replaced with AI

    One of the most alarming features of the MAHA report is its apparent reliance on AI-generated content with minimal human review. The report includes fabricated studies, misquoted references, and material copied from low-quality websites.

    At CDC, I personally experienced the rigors of scientific clearance: multiple rounds of review, correction of tables, validation of data sources, and internal debates about methodology. Was it tedious? Absolutely. But it ensured credibility and accuracy.

    What we’re seeing now is a complete breakdown of that system. It’s post-science: a world in which data is replaced by narrative, and fake studies hold the same weight as peer-reviewed research.

    What You Can Do

    As we concluded in our discussion, it’s time to raise your voice if you care about clean air, safe vaccines, and evidence-based medicine.

    Contact your local and national representatives. Ask for transparency. Demand that public health agencies be led by scientists, not ideologues. And most of all, keep yourself informed. Support journalists, researchers, and doctors working to separate truth from propaganda.

    To hear our full conversation, visit my YouTube channel, Thermometer. And to follow Dr. Farley’s thoughtful work on health systems and prevention, check out his Substack newsletter, Healthscaping.

  • Why You Should Think Twice About a Cruise Ship Hot Tub?

    If you’ve ever dreamed of soaking in a private hot tub and gazing out on the open sea on the deck of a cruise ship, you might want to think twice. At least until you ask a few pointed questions about how that hot tub is maintained.

    Earlier this year, CDC released a study that tracked a small but serious cluster of Legionnaires’ disease cases aboard cruise ships. Over an 18-month period, they documented 12 cases from just two ships. Ten people were hospitalized. Infections were caused by private hot tubs attached to staterooms, luxury perks that are supposed to help you relax and unwind, not send you to the ICU.

    What Is Legionnaires’ Disease and How Do You Get It?

    For those unfamiliar, Legionnaires’ disease is a severe form of pneumonia caused by inhaling mist or vapor that contains Legionella bacteria. The first known outbreak was in 1976 at an American Legion convention in Philadelphia—hence the name—and it was eventually traced to the air conditioning system of the hotel where the convention was held. Since then, we’ve learned that Legionella thrives in warm, wet environments where biofilms—those slimy layers of microbes—can form. Think cooling towers, showers, fountains… and, yes, hot tubs.

    How Do Cruise Ship Hot Tubs Cause Legionnaires’ Disease?

    The CDC investigation into these cruise ship cases revealed that the operating protocols for private hot tubs often don’t meet the same standards as those in public areas of the ship. They’re subject to less scrutiny, less frequent water replacement, and inconsistent disinfection practices.

    Because the bacteria are hard to culture in standard lab tests, cases are often missed or misdiagnosed—unless a physician orders a urine antigen test for Legionella or a specialized culture.

    Who Is Most at Risk for Legionnaires’ Disease?

    What makes this particularly frustrating is that Legionnaires’ is preventable. We have very clear guidance on how to keep hot tubs safe: regular scrubbing to remove biofilms, testing for pH and disinfectant levels, filtering and replacing water on schedule. But if the people responsible for cleaning these tubs aren’t doing that work, then passengers, especially older adults or those with weakened immune systems, are at risk.

    What Can You Do to Stay Safe on a Cruise?

    I’ve led investigations of large Legionella outbreaks before, including one in New York City that sickened dozens of people from cooling towers. I’m also now making sure to remind friends and family to consider it on a cruise ship.

    If you’re planning a cruise vacation, ask questions about how the tub is being maintained. You can even bring your own test strips if you want an extra layer of safety.

  • West Nile Virus in the UK: A Warning Sign from a Warming World

    This week, UK scientists confirmed something that, to me, was destined to happen. For the first time, West Nile Virus (WNV) have been detected in mosquitoes collected in Britain. To be clear, the scientists detected fragments of the virus. There is no evidence of an active outbreak, and no humans or animals have been infected. But it is a signal—a small but significant one—of how climate change is rewriting the rules of infectious disease geography.

    Table of Contents

    How is climate change linked to mosquito-borne disease in the UK?

    Mosquito-borne infections, like West Nile Virus, were previously thought to be diseases primarily of the tropics, areas around the Equator with intense heat and humidity. But the label “tropical disease” is increasingly obsolete.

    West Nile Virus is carried by mosquitoes, circulates primarily in birds, and occasionally spills over to humans and horses, sometimes causing serious neurologic disease. The virus is endemic across much of the globe—from the Middle East and Africa to Europe and the Americas—but, until now, it had not been found in British mosquitoes.

    That changed when researchers from the UK Health Security Agency and the Animal and Plant Health Agency, as part of its Vector-Borne RADAR project, tested thousands of mosquitoes from wetland areas in Nottinghamshire. In two samples of Aedes vexans mosquitoes, they found genetic traces of WNV. Note that these are just fragments, not live virus. While there is no evidence of ongoing transmission, the news is enough to raise worry about future outbreaks.

    What is West Nile Virus and how does it spread?

    West Nile Virus is classified as a vector-borne infection, akin to dengue and yellow fever. It typically circulates between birds and the mosquitoes that bite them. Occasionally, the virus spills over into humans and horses, where it can cause a range of illnesses—from mild febrile syndromes to life-threatening encephalitis. Most people infected never develop symptoms, but the potential for severe disease remains, particularly in older adults or those with weakened immune systems.

    Where was West Nile Virus found in UK mosquitoes?

    The fragments were detected in mosquito samples collected from wetlands near the River Idle in Nottinghamshire as part of . Specifically, two pooled samples of Aedes vexans mosquitoes—species that are native to the UK and sometimes found in high densities near summer-flooded riverbanks—tested positive for WNV genetic material. Out of 200 tested pools, only two returned a positive result, underscoring how rare the detection was, but also how meaningful.

    How is the UK managing mosquito-borne disease risk?

    The UK Health Security Agency has classified the risk to the public as very low and has issued guidance to healthcare professionals to consider WNV testing for unexplained encephalitis. Surveillance programs have been intensified in response, including continued monitoring of mosquito populations at wetlands, travel hubs, and areas with potential for mosquito introduction through trade and transit.

    The broader Vector-Borne RADAR program is working not only to detect viruses early, but to understand the complex ecology of how they enter and potentially establish in the UK. These early warning systems are essential for preventing future outbreaks and enabling rapid response.

    Could tropical infections become common in the UK?

    What this detection tells us is that the UK’s climate is becoming more accommodating to pathogens once thought foreign. Mosquito species that can spread disease are finding it easier to survive and thrive, and the viruses they carry are traveling with them. And this is not an isolated case. Across Europe, the range of mosquito-borne infections has expanded in recent years, including dengue in France and chikungunya in Italy. Climate change is one of the most important drivers of emerging infectious diseases.

    We’ve spent decades thinking of certain infections as someone else’s problem, afflictions confined to equatorial latitudes or the distant global South. But rising temperatures, erratic precipitation, and warming wetlands are erasing those old boundaries. Disease vectors are moving, and with them, so are the pathogens they carry.

  • How Listeria Outbreaks Are Detected—and Why That Work Is Getting Harder

    When people think of food safety, they usually picture inspectors in white coats and hairnets walking around a factory floor. That’s certainly part of the process. But detecting and responding to foodborne outbreaks like listeriosis involves an entire hidden infrastructure that most people never see. Right now, that system is being eroded.

    Why Is Listeria So Hard to Diagnose?

    Let me start with something simple: it’s hard to diagnose Listeria monocytogenes infections. Microbiologists call the bacterium “fastidious.” That means it doesn’t grow easily in the lab, especially not from blood or spinal fluid cultures. In addition, many doctors do not think about even testing for the infection, because the symptoms of fever, headache, diarrhea, and confusion are vague enough to be mistaken for a number of other illnesses. Diagnosis depends on a doctor suspecting the disease, then ordering specialized diagnostic tests.

    How Are Listeria Outbreaks Detected and Tracked?

    Even when a patient is correctly diagnosed, that’s only the beginning. What turns a case of listeriosis into an outbreak investigation is the public health infrastructure that surrounds clinical medicine.

    In the United States, we’re fortunate to have a system called the Listeria Initiative, developed by CDC and other agencies, which requires every confirmed case of listeriosis to be reported and investigated. Epidemiologists interview every patient reported and collect detailed food histories. State laboratories then test the patient’s specimen to perform “”DNA fingerprinting” of the bacteria using techniques like whole genome sequencing.

    The DNA fingerprints of Listeria cases are then compared across a national database to identify clusters—cases in different states that may look unrelated until the lab results reveal the patients were infected with the exact same strain. If the strains match, it usually means the patients likely ate the same contaminated food product.

    The cases I discussed in my last post—one linked to nutritional shakes for elderly adults, the other to prepackaged sandwiches—only came to light because of this type of careful, labor-intensive work. In both instances, there were long gaps between early cases and later ones. It was only when new patients showed up with genetically identical strains of Listeria that investigators reopened cold cases, reviewed food production and distribution records, and eventually identified the contaminated products. That process can take months, even years.

    Why We Still Need People—Not Just Technology

    This is not something that artificial intelligence can do automatically. It requires human beings, including highly skilled public health laboratorians, epidemiologists, and food safety investigators, working together across jurisdictions, often with incomplete information and limited resources. It’s the kind of work that gets no attention when it succeeds and becomes the focus of blame when it doesn’t.

    Why Public Health Surveillance Is at Risk

    This brings me to a growing concern. Many of the systems that allow us to detect outbreaks, including public health labs, food inspection units, CDC epidemiology programs, are being scaled back or threatened with cuts. When budgets are slashed, what disappears first is often the slow, unglamorous work of surveillance: the phone calls to patients, the food history questionnaires, the genetic typing of bacteria, and the cross-matching of data across states. Without these, dangerous outbreaks like the ones I described won’t just be harder to solve. They’ll be harder to even detect in the first place.

    So when I hear people say we have the safest food supply in the world, which is largely true, I always add that it only stays that way if we keep investing in the people and systems that keep us safe.

    The next time you see a headline about a food recall or a bacterial outbreak, remember that behind it are teams of people doing painstaking work to make connections that most of us would never see.

  • How Listeria Found Its Way Into Shakes and Sandwiches

    Listeria monocytogenes is not the kind of bacteria that usually grabs headlines. It doesn’t spread from person to person. It doesn’t cause surges in hospitals. But it does something far more insidious: it lurks quietly in food production environments, contaminates products without obvious warning signs, and sickens people least equipped to fight it off. That includes older adults, people with weakened immune systems, and pregnant women. When it causes illness in those people, it can lead to death.

    What Is Listeria and How Does It Cause Illness?

    Listeria is a hardy bacterium. It can survive and even multiply in refrigerated environments where most other bacteria shut down or die. It thrives in moist, cool areas of food processing facilities and clings to surfaces in the form of a sticky biofilm, which is basically a slime layer that resists ordinary cleaning. Once it gets into a food product—whether it’s a sandwich, a shake, or deli meat—it can stay there, undetected, until someone eats it. For some people, that exposure is deadly.

    When Listeria causes infection, it’s called listeriosis. In healthy adults, it may cause a mild gastrointestinal illness or nothing at all. But in people with weakened immune systems, the story is very different.

    The bacteria can move from the gut into the bloodstream and even into the central nervous system, causing sepsis or meningitis. Pregnant women are also at high risk. They may experience only mild symptoms themselves but can suffer miscarriage, stillbirth, or severe infection of the newborn.

    Patients require treatment with high-dose intravenous antibiotics, including ampicillin and gentamicin.

    Outbreak 1: Listeria in Nutrition Shakes for Elderly Patients

    The first outbreak began quietly in 2018. A few residents of long-term care facilities developed severe infections. It wasn’t immediately clear what tied them together. But at the end of 2024, after six new cases emerged with the same bacterial fingerprint, the CDC reopened the investigation. The common link turned out to be a frozen nutritional shake, one of those high-calorie supplements often prescribed to elderly or frail patients. Forty-two people were infected, 41 were hospitalized, and 14 died.

    Outbreak 2: Listeria in Prepackaged Sandwiches Across the Western U.S.

    The second outbreak, identified around the same time, hit a different population but followed a similar pattern. This time the contaminated product was pre-packaged sandwiches, distributed across California, Arizona, Nevada, and Washington by a company in San Fernando, California. These are the type of sandwiches I occasionally find myself buying when I’m on a long road trip or rushing through an airport to catch a flight. Ten people were hospitalized with severe listeriosis.

    Why Listeria Is So Dangerous in the Food Supply

    What connects these two outbreaks is the way the bacteria lingers on surfaces, in equipment, and in foods meant for people who are already vulnerable. And what makes listeriosis so tragic is how preventable it is. If we maintain rigorous food safety standards, keep up inspections, and fund the public health teams who detect the patterns that connect a death in one state to a sandwich in another.

    In the next post, I’ll explain how we track outbreaks like these, and why that detective work is becoming harder to do.

  • The AI Threat to Public Health We’re Not Prepared For

    When people talk about the risks artificial intelligence poses to humanity, they tend to focus on the most catastrophic outcomes: machines that operate beyond our control, or synthetic biology guided by AI creating bioterrorism agents, like smallpox. Those are legitimate and deeply concerning risks. In public health, some of the most dangerous crises come not only from what is real, but from what people believe is real.

    I’ve spent much of my career investigating infectious disease outbreaks and suspected bioterrorism incidents. I’ve seen how even a rumor can spread fear and confusion. Now imagine that fear fueled not by word of mouth, but by images, voices, and videos that appear completely authentic and are designed to manipulate. That is the immediate threat AI poses to public health.

    In a new article for STAT, I outline a scenario that’s disturbingly plausible: an AI-generated simulation of a smallpox outbreak in a region of geopolitical tension, complete with fabricated patient videos, doctored lab reports, and fake audio of overwhelmed doctors. If such content were disseminated simultaneously across social media, and echoed by influencers and elected officials, the result could be panic, misdiagnosis, overwhelmed health systems, and, if the setting involves rival powers, military escalation. It could lead to a global response, including a declaration of a public health event of international concern.

    Verifying an outbreak requires on-the-ground investigation combined with specimen collection and diagnostic testing. But if governments and the public have already made up their minds based on convincing fakes, the truth may not matter. Public health officials could be sidelined, overruled, or too late to stop decisions made by elected officials or military leaders.

    While it remains critical to address long-term threats from AI and synthetic biology, we also need to confront this more immediate challenge. That means training health professionals to spot and respond to deepfakes, creating protocols for media authentication, and building stronger connections between public health, technology companies, and security agencies.

    A disease doesn’t have to exist to cause harm. In this new era, perception alone may be enough to start a war—or paralyze a country’s response to the next real outbreak.

    The Immediate Public Health Risks from AI-Driven Disinformation

    While existential threats from AI often dominate headlines, the more urgent risk may come from realistic fake outbreaks created using current AI tools. Below are key areas where this threat can destabilize global health and security.

    1. Deepfakes Undermining Public Trust

    AI-generated images, audio, and video that simulate real patients, doctors, or news reports can convince the public of an outbreak even when none exists. Once trust is broken, health authorities may struggle to reestablish credibility, even with real evidence in hand.

    2. Geopolitical Escalation from Fabricated Crises

    A fake outbreak in a politically tense region can spark military reactions before public health investigations can confirm or disprove the threat. If two nuclear-armed nations interpret a deepfake event as a biological attack, the consequences could be catastrophic.

    3. Delayed or Misguided Emergency Response

    Emergency responses based on false data can misallocate resources, delay real care, and cause unnecessary panic. Health systems may be overwhelmed not by a real pathogen, but by fear-driven behavior and policy decisions.

    4. Historical Precedents Amplify the Risk

    From medieval plague rumors to Cold War HIV disinformation, history shows how infectious disease lies can trigger violence and public health collapse. Modern AI makes it far easier and faster to spread these lies with apparent credibility.

    5. Conflicting Standards Between Health and Security

    In fabricated outbreak scenarios, public health agencies and military or intelligence bodies may disagree on what counts as sufficient proof. Security officials may demand airtight evidence before de-escalating, while public health experts may already know the threat is fake.

    6. Lack of Deepfake Detection Protocols

    Most health and security systems lack processes to vet the authenticity of media content during a crisis. Without verified protocols and tools in place, officials might act on deepfakes instead of facts, especially under political pressure.

    7. Urgent Need for Training and Collaboration

    Health professionals need training to recognize AI-generated content. Governments must also create alliances between health, tech, and security sectors to build detection infrastructure and response protocols. Without these, fake crises may do as much harm as real ones.

    Read the full STAT article here

  • Worried About Your Cat’s Cough? It Might Be the Flu.

  • Flu Season Is Ending in the U.S. Why That Matters.

    Is flu activity decreasing in the United States?

    For once, I have some genuinely good news to share. Flu activity in the United States is finally tapering off. The CDC’s FluView surveillance system, which aggregates syndromic and lab-based surveillance data from across the country, reports that visits for flu-like illness are now below 2 percent. This is a clear indication that the worst of the season is behind us. We’re also seeing a continued drop in flu hospitalizations and the percentage of tests coming back positive. All of this points toward a steady decline, consistent with the pattern we expect during this time of year.

    Why does flu season happen in the winter?

    What I’ve always found interesting—and often overlooked by people outside of public health—is that this pattern, while reliable in temperate places like the U.S. with cold winters and dry air, does not hold true around the world. In tropical regions, for example, flu doesn’t follow a single, predictable curve. Instead, flu has multiple small peaks throughout the year. And here’s the other detail I think more people need to understand. The flu season we experience in the Northern Hemisphere is often shaped by what’s already happened in the Southern Hemisphere months earlier, particularly in Asia and Oceania, where many new flu strains first emerge.

    Why the End of Flu Season Still Matters

    While the decrease in flu activity is welcome news, it’s also a key moment to reflect on what we’ve learned and what comes next. Public health experts rely on global data to track and prepare for future influenza threats. Here are the most important things to understand about flu season timing, surveillance, and risk.

    1. Flu Season in the U.S. Follows a Predictable Pattern

    In temperate regions like the U.S., flu season typically begins in fall and peaks during the coldest months. The virus thrives in cold, dry air and spreads more easily indoors, where people gather closely.

    2. Tropical Countries Have Year-Round Flu Activity

    Unlike in the U.S., tropical regions experience multiple smaller flu outbreaks throughout the year. This unpredictability makes continuous monitoring essential in those areas.

    3. Global Flu Trends Shape the U.S. Season

    The strains that circulate in the U.S. often originate in the Southern Hemisphere. Monitoring outbreaks in countries like Australia and regions of Asia provides early warning for North America.

    4. Surveillance Systems Are the Backbone of Flu Response

    Tools like CDC’s FluView collect data from hospitals, labs, and clinics to monitor illness levels and detect emerging strains. This data guides public health decisions, vaccine formulation, and response planning.

    5. Vaccines Depend on Global Coordination

    Twice a year, the WHO reviews global flu data to recommend which strains should be included in the seasonal flu vaccines. This process relies on accurate, real-time data from dozens of countries.

    6. The End of Flu Season Is Not the End of Surveillance

    Even as cases drop, public health officials continue to collect and analyze data. This ongoing work ensures we’re not caught off guard by unusual strains or early surges.

    7. Better Flu Surveillance Helps Prepare for Future Pandemics

    Influenza surveillance isn’t just about seasonal flu. It also plays a critical role in detecting potential pandemic strains—making it a vital part of global health security.

    How is flu tracked in the U.S. and globally?

    This is why robust, global surveillance matters so much. When I first started working internationally for CDC back in 2003, many countries were still struggling to justify investing in flu surveillance. With other, more visibly deadly diseases like HIV and tuberculosis demanding attention, flu often seemed like a lower priority. But without reliable data, you’re flying blind. You can’t prepare vaccines effectively, and you miss early warnings about dangerous strains. The U.S. flu season might be over, but the work of tracking and preparing for the next one never stops. It’s the type of work in public health—quiet, rigorous, systematic disease surveillance—that goes unnoticed but is vital to our health security.

  • Why Are Invasive Strep Infections Rising—and What Parents Need to Know

    As an infectious disease physician and parent, I’ve learned to respect the power of common pathogens. One of the most concerning trends right now is the rise in invasive group A streptococcus (GAS) infections—especially in children.

    What is invasive strep, and how is it different from strep throat?

    When most people hear “strep,” they think of strep throat—fever, sore throat, maybe a rash—and a quick course of antibiotics. It is a common infection in children, believed to be transmitted primarily by droplets or, occasionally, by fomites. But invasive strep is something entirely different. It occurs when the bacteria move beyond the throat into parts of the body that should be sterile, like the lungs or bloodstream. That can lead to life-threatening illnesses like toxic shock syndrome or necrotizing fasciitis, the so-called “flesh-eating disease.”

    Why are invasive group A strep infections increasing now?

    The CDC recently reported that invasive group A strep infections have more than doubled from 2013 to 2022, after 17 years of stability. We don’t fully understand why. Changes in population immunity, evolving bacterial strains, or increased transmission may all be increasing the force of infection.

    Do antibiotics still work for invasive strep?

    The good news is that penicillin and amoxicillin remain highly effective. The bad news? More infections create more chances for resistance to emerge—and more stress for families, pediatricians, and hospitals.

    Personally, I’ve seen how easily strep can be misdiagnosed. One of my kids had fever, sore throat, and stomach pain. This sounded exactly like influenza to me, but it turned out he had strep throat. In kids, strep can sometimes cause symptoms similar to a stomach virus or flu, so it’s important to test before prescribing antibiotics.

    Why is antibiotic stewardship important right now?

    This rise in invasive infections reminds us of the larger issue: antibiotic overuse. While strep is still treatable with older drugs, unnecessary prescriptions accelerate the rise in drug-resistant infections not only in strep but in other bacteria as well. Overuse also disrupts the gut microbiome and contributes to other health issues, including some chronic conditions.

    Is there a vaccine for group A strep?

    Not yet—but we need one. Several group A strep vaccines are in development, and they could dramatically reduce severe disease and lessen our reliance on antibiotics. In the meantime, prevention and early diagnosis remain essential.

    How Parents Can Respond to the Rise in Invasive Strep Infections

    With invasive group A strep infections on the rise, it’s important for parents to understand the symptoms, risks, and protective steps they can take. Here’s what every caregiver should know about this serious health threat affecting children in 2025.

    1. Understand the Difference Between Strep Throat and Invasive Strep

    Strep throat is common and treatable, but invasive strep occurs when the bacteria spread beyond the throat into the lungs, blood, or soft tissues. These cases can lead to life-threatening complications like toxic shock or necrotizing fasciitis.

    2. Recognize Early Warning Signs in Children

    Invasive strep can sometimes start with vague symptoms—fever, stomach pain, fatigue—that mimic a virus. If your child’s symptoms worsen quickly, seek medical care immediately and request a strep test when appropriate.

    3. Don’t Skip the Strep Test Before Using Antibiotics

    Even if symptoms seem classic, it’s important to confirm strep with a test. Using antibiotics without confirmation contributes to resistance and may miss the real cause of illness.

    4. Use Antibiotics Responsibly

    If prescribed, follow the full course exactly as directed. Do not save or share leftover antibiotics. Responsible use protects your child and the broader community from resistance.

    5. Watch for Rapidly Spreading Symptoms

    Symptoms that spread quickly—such as redness or swelling on the skin, confusion, or breathing difficulties—could signal a serious invasive infection. These require urgent medical attention.

    6. Practice Good Hygiene at Home and School

    Teach your child to wash hands frequently, avoid sharing utensils or drinks, and cover coughs or sneezes. Strep spreads mainly by droplets, so everyday precautions help reduce risk.

    7. Support Vaccine Development and Public Health Measures

    Although no vaccine exists yet, several candidates are in progress. Supporting public health initiatives and awareness campaigns helps push vaccine development forward and improves community preparedness.

    How do you protect your kids from strep?

    If you’re a parent, here are some important reminders:

    • If your child has a sore throat and fever, get tested for strep before starting antibiotics.
    • Remember that abdominal pain and fever can sometimes be a sign of strep in children.
    • Use antibiotics only when truly needed, and always finish the full course.

  • Why New Yorkers Need to Pay Attention to Ticks This Year

    This spring, public health officials have issued warnings about increased tick activity in New York City and surrounding areas. And for good reason. With warming temperatures and a surge in acorn production, the risk of catching a disease transmitted by ticks, such as Lyme disease, is climbing.

    It may sound strange to hear that acorns are part of the problem. But here’s how it works. Oak trees produce acorns. When temperatures rise, the oak trees produce even more acorns than usual. Oak trees feed white-footed mice. These mice are the primary hosts (the animals that ticks feed off of to survive) for black-legged ticks, also known as deer ticks.

    Warmer temperatures means more acorns. More acorns means more mice. And more mice mean more ticks. As, if the mouse population drops, ticks start looking for other animals to bite and feed off of—like us humans. Over time, the force of infection rises.

    What Tickborne Diseases Should You Worry About?

    The most common concern in the Northeast is Lyme disease, which can cause fever, fatigue, joint pain, and a telltale rash. But blacklegged ticks can also carry other pathogens, including those that cause anaplasmosis, babesiosis, and Powassan virus—some of which can lead to serious neurologic illness.

    Ticks go through several life stages. The nymph stage is especially dangerous because the ticks are tiny—about the size of a poppy seed—and can transmit infections while going unnoticed.

    How Do You Prevent Tick Bites?

    Fortunately, tick prevention is simple and effective. Here’s what I recommend:

    What to Do If You Find a Tick

    If you find a tick attached to your skin, don’t panic—but act quickly:

    1. Remove it with fine-tipped tweezers: Grasp the tick as close to the skin’s surface as possible and pull upward steadily. Avoid twisting or jerking.
    2. Clean the area: Wash the bite site with soap and water, and apply antiseptic.
    3. Save the tick: Place it in a sealed container or plastic bag for identification, in case you develop symptoms later.
    4. Watch for symptoms: If you notice fever, rash, fatigue, or joint pain in the weeks following a bite, seek medical attention.

    A Personal Note on Prevention

    I grew up in New Jersey, where tick checks were a routine part of childhood. I recommend that all parents do the same. It’s important for all of us to spend time outdoors in nature, but we also stay vigilant for bugs that can bite us and infect us, what’s known as vector-borne diseases.

    Ticks are part of the natural environment, but so is the knowledge to protect ourselves. This year, if you’re spending time in the parks, woods, or even your backyard in the Northeast, take a few precautions. It’s a small effort that can make a big difference.

  • Where Is the CDC on Measles?

    Why silence from the CDC during a growing measles outbreak puts public health at risk.

    Why the CDC Should Be Leading the Measles Response

    This week, RFK Jr. told Congress, “I don’t think people should be taking … medical advice from me.” I agree. But that raises a deeper question—who should the public be listening to during a growing measles outbreak in the United States?

    In theory, the answer is simple: the Centers for Disease Control and Prevention (CDC). But in practice, the CDC has been disturbingly quiet.

    What the CDC Is Not Doing—but Should Be

    Under any previous administration—Republican or Democrat—there would be a predictable and robust federal response to a nationwide measles threat. Here’s what we’re not seeing right now:

    • Weekly briefings with CDC leadership and experts. During H1N1, there were regular press conferences. For measles in 2024? Zero.
    • Monthly clinical update calls for healthcare providers. These are essential for updates on diagnosis, vaccination, post-exposure prophylaxis, and infection control. None so far, except for one webinar for primary care clinics.
    • A national public education campaign. Measles spreads before symptoms appear. But so far, no visible campaigns on social media on mainstream media about early recognition or vaccine benefits.
    • Emergency funding to support state response. Local health departments need surge funding for contact tracing, vaccination clinics, and staff. There’s been no announcement. In fact, large amounts of infectious diseases funding was cut from state and local health departments ! This was funding originally allocated for COVID-19, then later re-programmed to support other infectious disease outbreak investigations and management just like what are needed for measles.

    Is Lack of Leadership to Blame?

    Some may point to the CDC having an acting director. But during the early days of the 2009 H1N1 pandemic, the CDC also had an acting director—and still mounted a strong, science-led response. (Perhaps more worrisome is that it’s not even clear if CDC has anyone serving officially as acting director right now.)

    Silence Is Dangerous During a Measles Resurgence

    The CDC doesn’t need to fight politics. It needs to fight the virus. Measles is one of the most contagious viruses known and can be deadly for children and people with weak immune systems. The U.S. eliminated measles in 2000. That progress is now at risk, and the force of infection is rising.

    Silence and inaction are not neutral. They’re dangerous.

    How Can You Protect Yourself from Measles?

    The best way to protect yourself from measles is by getting vaccinated with the MMR (measles, mumps, and rubella) vaccine, which is highly effective and provides long-term immunity. Two doses are recommended—typically given in childhood—but adults who are unsure of their vaccination status should consult a healthcare provider about getting immunized.

    In addition to vaccination, avoid close contact with individuals showing symptoms of measles, especially during outbreaks, and practice good hygiene like frequent handwashing. If you’re traveling internationally, make sure your immunizations are up to date, as measles remains common in many parts of the world.

    What Countries do not Vaccinate for Measles?

    There are no countries that officially prohibit measles vaccination, but several nations have very low measles immunization rates due to conflict, poor healthcare infrastructure, or limited access to medical services. Countries like Somalia, South Sudan, Yemen, Chad, the Central African Republic, and parts of Afghanistan and Nigeria often struggle to maintain consistent vaccination coverage, which increases the risk of outbreaks. In these regions, the measles vaccine is typically available through international aid or government programs, but challenges such as supply shortages, mistrust, and logistical barriers prevent widespread administration.

  • Why Yellow Fever Is Back in the Headlines—And What Travelers Need to Know

    A friend recently asked me if it was safe to travel to Colombia while recovering from cancer. Their concern was yellow fever, not crime or altitude.

    The CDC has issued a Level 2 travel alert—“Practice Enhanced Precautions”—due to increased yellow fever activity in Colombia, Peru, and Bolivia. If you’re planning to travel to one of these countries, especially areas near forests or jungles, you may need a yellow fever vaccine. And if your last dose was over 10 years ago, you might even need a booster.

    What Is Yellow Fever and How Does It Spread?

    Yellow fever is a viral infection transmitted by mosquitoes, particularly Aedes species. These are the same mosquitoes that spread dengue, chikungunya, and Zika. Together, these are known as vector-borne diseases. The virus has both an urban and jungle (sylvatic) transmission cycle, meaning it can spread between people in cities or jump from infected monkeys in forests to humans via mosquito bites.

    Many people infected with yellow fever have no symptoms, but in severe cases, it causes high fever, liver damage, jaundice (which gives the disease its name), and bleeding. There is no cure—only supportive care—and in the most serious cases, it can be fatal.

    What You Can Do to Stay Safe from Yellow Fever?

    1. Get vaccinated before travel

    If you’re visiting a yellow fever–endemic area, get the yellow fever vaccine at least 10 days before departure. Carry an International Certificate of Vaccination (often called the “yellow card”) as proof, since many countries—particularly in Africa and South America—require it for entry.

    2. Take mosquito precautions

    Use insect repellent with DEET, wear long sleeves and pants, and stay in well-screened or air-conditioned accommodations to reduce mosquito exposure. Mosquitoes that transmit yellow fever tend to bite during the day, particularly around dawn and dusk. Minimize outdoor exposure during these hours if possible.

    3. Monitor your health after travel

    If you experience symptoms such as fever, chills, muscle pain, headache, or jaundice after returning from a yellow fever–risk area, seek medical attention immediately and inform your healthcare provider of your travel history.

    4. Stay informed and proactive

    Follow public health updates and be aware of emerging outbreaks. Yellow fever is a reminder that environmental changes can lead to the spread of infectious diseases—preparedness is key.

    Is Climate Change Driving an Increase in Yellow Fever?

    Mosquito-borne diseases are surging globally, and climate change plays a major role. As temperatures rise, mosquito habitats expand into new areas. Urbanization and deforestation increase the chances of people coming into contact with infected animals and insects. And, when health systems are under strain, outbreaks are harder to contain.

    How contagious is yellow fever?

    Yellow fever is not contagious from person to person through direct contact like coughing, sneezing, or touching. Instead, it is transmitted through the bite of an infected Aedes or Haemagogus mosquito, which becomes a carrier after biting a person or primate infected with the virus. Because humans don’t spread the virus directly to one another, outbreaks depend heavily on mosquito populations and environmental conditions.

    The U.S. Has Its Own Yellow Fever History

    Yellow fever isn’t new to the Americas. In 1793, Philadelphia lost 10% of its population to a yellow fever epidemic. Mosquito control, vaccine development, and eventually the widespread use of air conditioning (which reduced indoor mosquito bites) transformed the outlook, and the force of infection declined in the U.S. and other countries in the Americas. But the disease hasn’t disappeared, and as the planet warms, the risk of outbreaks in previously unaffected areas grows.

  • What Is Creutzfeldt-Jakob Disease and Why Are Cases in Oregon Alarming?

    Over the past eight months, health officials in Hood River County, Oregon, have reported three cases of Creutzfeldt-Jakob Disease (CJD). Two of the three people have already died. It’s a small number, but it’s the kind of cluster that raises big questions because the disease is untreatable and 100% fatal.

    What Causes CJD?

    CJD is part of a family of illnesses caused by prions. Prions are misfolded proteins that damage brain tissue. Unlike bacteria or viruses, prions aren’t living organisms. They’re corrupted proteins that trigger a chain reaction in the brain, causing spongiform encephalopathy, a condition where brain tissue becomes riddled with holes. Think of it as a rogue protein convincing other proteins to turn against you.

    Symptoms of CJD

    Creutzfeldt-Jakob Disease progresses quickly and leads to severe neurological decline. While symptoms can vary slightly depending on the type, the overall pattern involves a rapid transition from subtle cognitive issues to profound brain dysfunction and, ultimately, death—often within a year.

    Early-stage symptoms

    • Subtle cognitive changes such as memory loss, impaired judgment, confusion, and difficulty concentrating.
    • Mood and personality shifts including anxiety, depression, irritability, and apathy.
    • Initial physical signs like balance problems, unsteadiness, or mild coordination issues.

    Mid-stage symptoms

    • Rapidly progressing dementia along with speech and swallowing difficulties.
    • Involuntary muscle movements (myoclonus), vision problems, and worsening coordination leading to frequent falls.
    • Stiffness, tremors, and trouble walking independently.

    Late-stage symptoms

    • Severe cognitive and physical decline resulting in mutism, incontinence, and immobility.
    • Complete loss of voluntary muscle control, leading to coma.
    • Death, typically due to infection or respiratory failure related to immobility.

    Types of Creutzfeldt-Jakob Disease

    Creutzfeldt-Jakob Disease (CJD) is not a singular illness but a group of rare, fatal brain disorders that differ in how they develop. While all types involve the buildup of misfolded prion proteins that destroy brain tissue, the source of these prions can vary—ranging from spontaneous occurrence to inherited mutations or even transmission through contaminated medical instruments or food.

    1. Sporadic CJD (sCJD)

    The most common form, sporadic CJD (sCJD), accounts for approximately 85–90% of cases. It arises without warning or clear cause, typically affecting individuals over the age of 60. Researchers believe that spontaneous mutations in the PRNP gene, which codes for the prion protein, may play a role, but no definitive risk factors have been identified.

    2. Familial or genetic CJD (fCJD)

    Familial or genetic CJD results from inherited mutations in the PRNP gene. It tends to cluster in families and represents 10–15% of known cases worldwide. The age of onset and rate of progression can vary depending on the specific mutation, but the condition is always fatal.

    3. Iatrogenic CJD (iCJD)

    Iatrogenic CJD is extremely rare and results from accidental transmission during medical procedures. Documented cases have occurred through exposure to contaminated surgical instruments, dural grafts, corneal transplants, or human-derived growth hormones. Thanks to strict sterilization protocols and modern donor screening practices, such instances have become exceptionally uncommon.

    4. Variant CJD (vCJD)

    Lastly, variant CJD is linked to eating beef products infected with Bovine Spongiform Encephalopathy (BSE), or “mad cow disease.” First identified in the United Kingdom in the 1990s, vCJD typically affects younger people, often in their 20s or 30s, and has a longer incubation period compared to other forms. Though symptoms may progress more slowly, the disease is still invariably fatal.

    How Do People Get Infected with Prions?

    That’s one of the scariest parts. Most CJD cases are sporadic, meaning we don’t know exactly how the person got infected. But we do know that prions can be transmitted through contaminated meat, surgical equipment, or, in rare cases, inherited genetic mutations. In animals, similar diseases spread when nervous system tissue is consumed—often through industrial feed practices. That’s what caused the mad cow disease outbreaks that were widely discussed in the 1990s.

    Why a Cluster of Prion Disease Cases Matters?

    It’s easy to shrug off one or two deaths from a rare disease. But three in one area? That deserves a rigorous investigation. Prion diseases are poorly understood, difficult to detect early, and always lethal. This cluster is a reminder that even in an era of advanced diagnostics and molecular testing, some infectious threats still evade our best tools and public health surveillance systems.

    What Can We Learn from This?

    A lot. First, we need to keep investing in disease surveillance for rare pathogens—especially in rural or underserved areas. Second, this is a reminder that the boundary between environmental and human health is thin. Just like chronic wasting disease in deer, prion threats may be lurking in ecosystems we don’t fully understand.

    And finally, it’s personal. One of my first instructors in field epidemiology and outbreak investigation at CDC, Dr. Stephen Thacker, died from a prion disease he likely acquired decades earlier while living in the United Kingdom. It was a tragic and powerful lesson in humility: the idea that the microbes we study may be the ones that kill us.

  • Why Your ZIP Code Predicts Health More Than DNA

    If you want to predict someone’s life expectancy, don’t bother asking about their DNA. Ask for their ZIP code.

    This is the core message behind a new report from the World Health Organization. It’s also a long-overdue challenge to the way the average person and policy maker typically thinks about health, especially in high-income countries like the United States. Government and individuals pour resources into health care services, gene therapies, supplements, and wearable devices, while mostly ignoring the basic truth that the most effective and lasting improvements in population health come from changing the conditions in which people live, work, and age.

    That means changing the rules that shape our environment, our economy, and our social fabric.

    The WHO report offers a comprehensive framework. It recommends policies to address economic inequality, strengthen public services, and dismantle systems of discrimination. It calls for governments to regulate harmful commercial practices and ensure that emerging trends—like climate action and digital transformation—advance equity rather than widen gaps. Most importantly, it underscores a hard truth: health equity is a political choice. The social determinants of health, as they are commonly known, should more accurately be labeled political and commercial determinants of health.

    That choice doesn’t just live in Washington or Geneva. It plays out in local zoning boards deciding where affordable housing gets built. It plays out in school boards deciding on lunch programs, health curricula, and indoor air quality. And it plays out in businesses that either choose to uphold decent labor practices or exploit loopholes that keep wages low and conditions unsafe.

    What we need is a whole-of-government and whole-of-society shift. That includes embedding health equity into every level of decision-making, not as an afterthought but as a design principle. It means evaluating public policies based on whether they help or harm health across different groups—and especially those who have been historically excluded or disadvantaged.

    In other words, we need to stop mistaking health care for health.

    Until we take social, commercial, and environmental determinants seriously, we’ll keep spending more and getting less. The good news? We already know what works. The bad news? Here in the U.S., the current administration talks about protecting Americans from dangerous substances and addressing the rising incidence of chronic diseases. But the programs the Trump Administration is cutting and the policies it’s enacting will make our health worse.

  • The COVID Contrarian Playbook Is Winning. But It’s Built on Bad Faith.

    A professor recently posted on social media that he was blocked by a prominent COVID-19 contrarian who has now been appointed to a senior position at the FDA. His post struck a nerve for me, because I’ve seen the same pattern play out again and again since the pandemic started.

    Loud voices from this community and now the “Make America Healthy Again” (MAHA) community build influence by touting principles that seem legitimate, but, when challenged, they fail to apply those principles and to debate in good faith. The most celebrated COVID contrarians rarely mean what they say.

    When they claim they’ve been “censored,” it’s not that they were actually silenced and not permitted to speak. They were, in fact, amplified across conservative media, state legislatures, and even the Trump White House. What they really mean is that liberal institutions and media outlets didn’t celebrate them. What they wanted was a louder microphone and widespread praise. What they got was legitimate criticisms that their recommendations were rarely practical, ethical, or effective.

    When they demand “free speech,” it usually comes with an important caveat. Speech is only free when it doesn’t promote anti-racist policies, LGBTQ rights, or public health interventions that they deem too “woke.” Here is a long list of words that have been flagged at NIH, CDC, and National Science Foundation as problematic when awarding grants, conducting research, naming programs and job titles, and communicating to the public. Can you really be an advocate of free speech and open scientific debate when you restrict words and ideas that you find problematic?

    And when they call for “evidence-based policy,” it’s often the inverse; policy-based evidence. Data is cherry-picked to justify a predetermined belief and a policy outcome they want. For example, the voice of people who died from COVID are ignored in favor of those who lived and escaped without severe health consequences of infection.

    These tactics have proven alarmingly effective. The goal, unfortunately, is not to generate objective evidence about how to advance knowledge and improve health. Or to generate scientific consensus about the best approaches to study and solve a problem. The goal seems to be power. And the costs are real: trust in science, advancing health equity, and protecting the public from infectious and environmental threats. As someone who has spent a career trying to improve public health through evidence and community engagement, I find this shift deeply troubling. Once bad faith becomes the currency of influence, the public and public health lose.

  • Why Public Health Labs Are Still Essential in the Age of Academic and Commercial Labs

    Public health labs fill an essential market failure. When people think about laboratory testing, they often imagine major hospital systems, academic medical centers, or large commercial labs processing thousands of samples a day.

    But behind the scenes, public health laboratories do the critical testing that these institutions often can’t—or won’t—do. These labs address a fundamental gap in the healthcare system: testing that is essential for protecting communities often isn’t profitable, scalable, or logistically feasible for commercial or academic institutions.

    Commercial Labs Prioritize Profit, Not Public Good

    Commercial laboratories exist to make money. That’s not a criticism. It’s simply a fact of their business model. They focus on tests that are ordered frequently, reimbursed reliably by insurance companies, and supported by scalable operations. But many of the most important public health tests don’t meet those criteria.

    Testing for a rare but deadly disease like botulism or rabies might only happen a few times a year in a single state. Testing air, soil, or food samples for chemical contamination isn’t reimbursed by health insurance. Running lab-based surveillance and testing for outbreaks or bioterrorism threats rarely pays the bills.

    Even when commercial labs have the technical capacity, they often lack the flexibility or incentive to respond to public health emergencies. They don’t build relationships with public health agencies or law enforcement. They aren’t equipped to process high volumes of specimens at short notice without guaranteed payment. And they usually don’t maintain the specialized equipment or trained personnel needed to handle emerging or exotic threats.

    Academic Labs Lack Scale, Certification, and Infrastructure

    Academic laboratories are centers of scientific innovation, but they are not built for rapid, high-volume clinical testing. Most are designed for research, not 24/7 diagnostic operations. Their staff are researchers and students, not full-time microbiologists or certified lab technicians. And while they often have access to cutting-edge tools, they typically lack the standardized protocols, quality controls, and certification processes required for clinical testing that guides patient care or public health decisions.

    Academic institutions also don’t have the legal and procedural infrastructure for chain-of-custody testing in criminal or bioterrorism cases. They’re not integrated into emergency response systems. And they rarely have formal agreements with state or federal agencies to coordinate testing during a health crisis.

    Public Health Labs Serve a Unique and Irreplaceable Role

    Public health labs are uniquely designed to fill this gap. They exist to serve the public good, not to generate profit. They are funded by governments, staffed with specialized personnel, and certified for high-complexity testing. They maintain the equipment and protocols needed for rare, emerging, or dangerous pathogens. And they operate within emergency response systems, able to scale up operations rapidly during an outbreak or threat.

    In times of crisis—whether it’s a new virus, a chemical spill, or a white powder in the mail—it is public health labs that step in. Without them, our ability to detect and respond to public health threats would be significantly weakened. Commercial and academic labs play critical roles in the broader healthcare ecosystem, but they cannot replace the vital functions of public health laboratories.

  • HIV Diagnoses Are Rising Again — and the U.S. Just Weakened Its Surveillance System

    New CDC Data Shows HIV Diagnoses Increased in 2023

    On April 29, the Centers for Disease Control and Prevention (CDC) released its annual HIV Surveillance Report, which updates trends in new diagnoses, deaths, and epidemiology for the previous year. One alarming finding: in 2023, 39,201 people aged 13 years and older were newly diagnosed with HIV. That’s a rise from the 38,043 cases reported in 2022—an increase that reverses years of slow but steady progress in controlling the epidemic.

    But an even more concerning revelation was hidden in plain sight on the CDC’s website: CDC’s surveillance systems are already suffering from recent budget cuts and staff reductions.

    CDC Halts PrEP Coverage Reporting Due to Staff Cuts

    In a striking admission, CDC wrote:

    “In 2024, CDC paused pre-exposure prophylaxis (PrEP) coverage reporting for one year to update overall PrEP coverage estimates using newly available data sets and determine the best way to present PrEP coverage. However, CDC is unable to resume PrEP coverage reporting at this time, due to a reduction in force affecting the Division of HIV Prevention (DHP). As part of this staffing reduction, the DHP branches that produced HIV incidence estimates and provided the statistical expertise needed to assess PrEP coverage were eliminated.”

    CDC added that it is “currently evaluating plans and capacity to resume this work.”

    This is more than just a bureaucratic issue. The inability to measure who is receiving PrEP—one of the most powerful biomedical tools we have to prevent HIV—is a critical failure. It means the U.S. can no longer track one of the most important indicators of HIV prevention success or failure.

    HIV Surveillance Is a Public Health Lifeline

    The suspension of PrEP coverage reporting, combined with the elimination of key analytic branches at the Division of HIV Prevention, should serve as a wake-up call. Surveillance is the foundation of public health: it tells us who is affected, where they are, and what interventions are needed.

    Without timely and accurate data on HIV incidence and PrEP uptake, public health officials are flying blind. They can’t assess which communities are falling behind, where prevention efforts are working, or how to allocate resources efficiently. For HIV—a virus that can spread asymptomatically for years—this lack of visibility is especially dangerous.

    Why Surveillance Funding Must Be Restored

    Investing in HIV surveillance is not a luxury—it is a necessity. Every data point represents a person who may or may not be receiving life-saving treatment or prevention. Robust surveillance systems are the only way to target interventions to promote health and reduce infections being transmitted to others.

    When surveillance systems are weakened, the virus spreads undetected, and the consequences ripple outward: more infections, more deaths, higher healthcare costs, and avoidable suffering. A country that claims to want to end the HIV epidemic cannot afford to dismantle the very tools that make that goal achievable.

  • Why Measles Treatment Research Matters—Even If Vaccination Is the Priority

    Health conspiracy thinkers are occasionally right about some issues—for the wrong reasons. The latest example? The news that Robert F. Kennedy Jr. wants more research into treatments for measles infection.

    According to The New York Times, the Department of Health and Human Services is directing agencies like the CDC and NIH “to explore potential new treatments for the disease, including vitamins.”

    The article quotes several public health experts—some of whom I know personally—criticizing the effort. Their concerns are valid: they fear research into treatments might divert resources from prevention or give the public the false impression that vaccination is unnecessary.

    Should We Invest in Measles Treatment Research?

    Several things can be true at the same time:

    First, I agree that the highest priority for federal measles resources is reducing the force of infection through large-scale vaccination campaigns. It is rising when it should be near zero.

    Second, some people will get infected and need treatment for measles. That includes a mix of people—some (or their parents) who chose this risk by refusing or delaying vaccination, and others who had no choice: infants under age 1, people with immune compromise, or those who didn’t respond to both recommended doses.

    Third, there hasn’t been sufficient research into antiviral therapies for measles—or for many other infectious diseases. The golden age of antimicrobial therapy coincided with the golden age of vaccine development. Because vaccines were so effective, there was little incentive—either public or private—to invest in treatments for diseases that seemed headed for elimination.

    I’ve argued before that we need more investment in antiviral research. I disagree with experts quoted in the article who claim that there’s already been enough research into measles treatments. The last major clinical trials involved ribavirin—and that was decades ago.

    Why We Need Both Vaccination and Treatment

    My hope is that this administration will eventually undo the damage that’s been done—and commit to both preventing and treating measles. But honestly, I’m not feeling particularly hopeful right now.

    If we want to rebuild trust in public health, we have to show that we’re serious about both preventing illness and caring for those who still get sick.

  • The U.S. Is Getting Weaker on Food Safety — and That’s a Big Problem

    I started by career at CDC investigating outbreaks of foodborne diseases. I learned that they are one of the leading causes of preventable illness in the United States and that protecting the public requires rigorous standards from farm to fork, not just voluntary efforts or wishful thinking.

    That’s why recent announcements from the U.S. Department of Agriculture (USDA) are so concerning. The agency has officially withdrawn a proposal that would have required poultry producers to limit the amount of salmonella bacteria in chicken and turkey products. This plan, years in the making, was designed to prevent an estimated 125,000 illnesses from contaminated poultry every year.

    Instead, citing industry concerns about cost, feasibility, and food waste, the USDA scrapped the rule entirely. Officials also delayed enforcement of a related regulation targeting breaded and stuffed raw chicken products — foods that have repeatedly been linked to Salmonella outbreaks.

    Why Foodborne Disease Is Still a Major Threat

    The message seems unmistakable: when it comes to food safety, Americans are increasingly being left on their own. Sadly, the FDA was first established in 1906, because of public uproar about food contamination and widespread recognition by elected officials that food producers cannot be trusted to make food safe without regulation. Indeed, as the food system has become increasingly globalized and industrialized, the U.S. has been adapting by making standards progressively more rigorous – a model for other countries, including China.

    It’s a dangerous step backward. Salmonella causes about 1.35 million infections and 420 deaths annually in the U.S., according to the CDC. That number hasn’t changed significantly in two decades, despite improvements in science and technology. Chicken and turkey are among the most common sources of infection.

    What Stronger Salmonella Standards Would Have Meant

    The Biden-era proposal would have been a major step forward — treating dangerous salmonella strains in poultry much like we now treat certain E. coli strains in beef: as contaminants that should not be allowed into the food supply. Setting real limits, not just guidelines, would have finally matched regulation to scientific knowledge. Even if bacteria contamination cannot be eliminated, safety can be improved by limiting the infectious dose people are exposed to.

    Industry groups applauded the withdrawal, arguing that the proposed standards were “legally unsound” and “misinterpreted the science.” But food safety experts and former USDA officials were blunt: this decision puts businesses’ short-term interests over public health. If Salmonella isn’t a contaminant, is it a nutrient?

    We Need Stronger — Not Weaker — Food Safety Protections

    Food safety should not be optional. It should not hinge on voluntary efforts, or whether companies feel it’s convenient or cost-effective. Strong, enforceable standards from farm to fork are the only proven way to reduce the burden of foodborne disease.

    The U.S. can and must do better.

  • Tuberculosis Is Rising Again in New York City — A Warning We Saw Coming

    When I oversaw infectious disease control for New York City from 2011 to 2017, one of our most important public health achievements was driving the city’s tuberculosis (TB) rates to the lowest levels in history. It took decades of investment, dedication, and innovation to accomplish that.

    But even during that period of success, my colleagues and I worried. We knew that TB had never truly disappeared. We feared that rising global rates of TB, combined with persistent underinvestment in domestic TB control, could one day undermine everything we had worked so hard to achieve. Unfortunately, that fear is becoming a reality.

    New Data Show TB Cases Are Rising in New York City

    A recent article in Healthbeat confirms what many of us in the public health field have been seeing: TB cases in New York City are rising again. In 2023, the city reported 839 confirmed cases — a 28% increase from the year before, and the highest number since 2011. This reverses decades of progress and echoes a troubling pattern that public health experts know all too well: crisis leads to investment, but as memories of the crisis fade, so does the commitment to prevention. It’s the well described cycle of panic and neglect.

    Why Controlling TB Requires More Than Medical Care

    TB is not a simple disease to control. It’s airborne, yes. But it’s also deeply tied to social determinants like housing, nutrition, and access to healthcare. Effective control demands a strong public health workforce for contact tracing, treatment adherence, and community outreach. It also demands stable, long-term funding. Yet, as Healthbeat reports, New York City’s TB programs are now strained by staffing shortages, federal funding cuts, and the termination of CDC support staff.

    The Growing Threat of Multidrug-Resistant TB

    Adding to the challenge is the global rise of multidrug-resistant TB, which complicates treatment and threatens to roll back even more of the gains we made in the 1990s and 2000s. Without sustained investment in domestic TB control — and a recognition that infectious diseases don’t require visas and stop at international borders — we risk normalizing these rising numbers.

    Why Sustained Public Health Investment Matters

    The public health success story of TB control in New York City was not inevitable, and it should not be taken for granted. It was built through relentless effort and investment in active surveillance, contact tracing, and directly observed therapy. If we allow the system to weaken further, the cost — in lives, dollars, and public trust — will be far greater than the cost of prevention.

    Just as we see measles resurging now, it seems inevitable that the cuts to domestic and global public health funding will also lead to TB’s resurgence not just in New York City, but around the country.

  • Could the U.S. Face a Post-Soviet Style Collapse of Public Health?

    What happens when you cut public health funding for prevention and treatment?

    All of us who work in health have been quietly asking ourselves the same uncomfortable question: What happens if the U.S. keeps cutting public health funding, loses more experienced staff, and the public’s trust in health authorities keeps eroding?

    What Happened After the Soviet Union Collapsed?

    The nightmare scenario isn’t theoretical. We’ve seen it before: after the collapse of the Soviet Union in the early 1990s. When the newly independent states suddenly lost public health funding, staffing, and medical supplies, the consequences were catastrophic. Measles and diphtheria spread widely. Tuberculosis resurged, and even today, many of those countries continue to struggle with multidrug-resistant TB (MDR-TB).

    Public health systems can fall apart faster than we like to believe, and rebuilding them is slow, expensive, and often incomplete. Imagine what happens when a bridge does not get repaired over decades. Small cracks appear, but the bridge still functions. Until one final crack is too much, and the entire bridge collapses. That’s what happens in public health. The damage is slow and not obvious to most people – until finally it isn’t.

    New JAMA Study Quantifies the Risks for the U.S.

    A new study in JAMA puts some numbers around what risks the U.S. might face if we continue down this path. The researchers modeled future outbreaks of vaccine-preventable diseases under different scenarios of vaccination coverage and public health investment. Their findings should be a wake-up call.

    Which Diseases Are the Greatest Threats?

    The highest risks were for two diseases we often think of as relics of the past, but that I have been trying to sound the alarm on: measles and polio. Declining vaccination coverage, combined with a high attack rate, could easily lead to more illness, hospitalizations, and deaths from both. Unlike COVID-19, which initially spread asymptomatically, these diseases hit young children fast and hard, overwhelming hospitals and causing lifelong complications or death.

    Why Diphtheria May Be Less of a Concern

    Perhaps the only somewhat reassuring finding was that, even under dire scenarios, the U.S. is not likely to experience widespread, deadly outbreaks of diphtheria like the post-Soviet states did. But that’s little comfort when we’re talking about losing ground on diseases we know how to prevent.

    Public Health Systems Must Be Protected

    The lesson is clear: public health is not self-sustaining. It requires constant investment, vigilance, and public trust. Funding for surveillance systems, outbreak investigations, and emergency preparedness and response must be continuous. Once it starts to fray, the damage can spread faster — and last longer — than we want to imagine.

  • Deadly Virus in the Sierra Nevada: What You Should Know About Hantavirus in Mammoth

    Hantavirus infections are rare but deadly. Here’s what you need to know about the recent outbreak in California.

    Why Are People Dying from Hantavirus in Mammoth Lakes?

    A recent outbreak investigation from Mammoth Lakes, California—a stunning ski destination nestled in the Sierra Nevada—has sounded an alarm: several deaths linked to hantavirus have occurred in the area. The most recent was a young adult who, according to local health officials, didn’t have clear evidence of rodent exposure at home but may have encountered mice in the workplace.

    Hantavirus was also in the news recently following the death of famed actor Gene Hackman. He was suffering from advanced Alzheimer’s and depended on his wife as his primary caretaker. Tragically, she contracted hantavirus and died without anyone knowing. Hackman passed away soon after due to complications from his illness and lack of care.

    What Is Hantavirus and How Is It Spread?

    As someone who’s studied infectious diseases across the globe (and who loves snowboarding in Mammoth!), I’m always struck by how often we overlook threats right here at home. Hantavirus is a lethal disease carried by deer mice—common in the western U.S.—and transmitted when people inhale particles from rodent droppings, urine, or saliva. It doesn’t spread from person to person.

    Instead, it lurks in places we often think of as harmless: a dusty garage, a poorly sealed cabin, or a rarely cleaned basement. Although it primarily occurs in the southwestern United States, I recall a case from New York about 15 years ago: someone cleaning their Long Island basement contracted hantavirus and tragically died.

    How to Protect Yourself from Hantavirus

    What’s happening in Mammoth reminds us that environmental risks are all around us. Protecting our health includes keeping our surroundings free from fomites—objects or materials likely to carry infection—and from pathogens can be spread through the air during cleaning.

    So here’s one practical takeaway: wear a mask and gloves if you are cleaning an area where rodents might have been. Yes, even now. Your leftover N95s and gloves from COVID? They’re perfect for sweeping up mouse-infested areas.

    Why This Outbreak Matters

    This outbreak is another reminder that our health is tightly linked to the environment around us. When we understand those connections—and take simple steps to protect ourselves—we prevent disease, even in places as idyllic as a mountain ski town.

    If you want to learn more, watch my discussion with veterinarian, virologist, and disease ecologist Jon Epstein at ThermometerHQ.

  • Why Gonorrhea in Alaska Signals a Need for Early STI Testing

    STIs may be asymptomatic, before they become severe

    The news out of Alaska is alarming: a cluster of gonorrhea cases that appear to be more severe than usual, spreading beyond the genitals to the bloodstream, heart valves, and joints. This isn’t just a local concern—it’s a national wake-up call about how we approach sexually transmitted infections (STIs).

    What makes the Alaska gonorrhea outbreak different?

    Unlike most cases of gonorrhea, which are confined to the genitals, this outbreak involves disseminated infections—bacteria spreading to other parts of the body and causing serious complications. It’s a sign of how dangerous untreated or undetected STIs can become.

    Why STI testing shouldn’t wait for symptoms

    Many STIs, including gonorrhea, spread through asymptomatic transmission—meaning a person can feel completely fine while still carrying and spreading the infection. Waiting for symptoms can delay diagnosis, treatment, and allow further spread or long-term complications.

    How early screening helps stop the spread

    Routine STI testing is one of our most effective prevention tools. For people with new or multiple sexual partners, it’s critical. When caught early, gonorrhea is usually easy to treat. But the longer an infection goes unnoticed, the greater the risk of damage and transmission.

    Why surveillance systems matter in STI control

    Public health infectious disease surveillance systems are essential for spotting trends and detecting outbreaks. Programs that track lab testing results for specific pathogens and monitor for unusual patterns—like this Alaska cluster—can help prevent widespread transmission before it starts.

    Takeaway: Schedule a screening

    If you haven’t been tested for STIs recently, now is the time. Testing is quick, confidential, and widely available. It’s one of the simplest and most powerful steps you can take to protect your health and your partners’ well-being.

  • Allergies or a Virus? How to Tell the Difference This Spring

    Sniffles, sneezing, or sore throat? Here’s how to know what you’re dealing with.

    Spring has arrived in New York City. There’s warmth in the air—but also a lot of pollen. If you’re sniffling, you now have that age-old question: are my symptoms just allergies, or am I sick with a virus?

    This is an issue I’ve been dealing with myself recently: a stuffy nose, post-nasal drip, a sore throat, and lots of sneezing. Here are five reliable ways to figure out what’s really going on.

    1. Timing and Triggers

    Allergies are extremely common, reported by 1 in 3 adults and more than 1 in 4 children in the U.S. symptoms often begin suddenly after exposure to pollen, dust, or mold and can persist for weeks or even months. In contrast, a cold or upper respiratory infection tends to build up slowly, peaks after a few days, and clears up within a week or so.

    2. Sneezing and Itchiness Are Clues

    Itchy eyes, nose, or throat—and frequent sneezing—are classic signs of allergies. These symptoms are rare with most viral infections. If you’re constantly rubbing your eyes or sneezing in fits, you’re likely reacting to allergens.

    3. Fever and Fatigue

    Fever, chills, muscle aches, and extreme fatigue point to an infection. Allergies might make you feel sluggish, but they don’t cause body aches or temperature changes.

    4. At-Home Tests for Viruses

    You can now buy over-the-counter tests that screen for COVID-19 and two types of flu. A positive result means you’ve got an infection. But a negative test doesn’t rule one out completely. It might be a virus not included in the kit. For COVID-19, it may mean you had the virus, but are outside of the infectious period.

    5. Response to Medications

    Allergy medications—like antihistamines or steroid nasal sprays—typically help within a day or two. If your symptoms improve, allergens are probably to blame. If not, it might be time to consider a viral cause.

    Bottom Line

    If you’re itchy, sneezy, but otherwise well, it’s probably allergies. But if you’re achy, fatigued, and have a sore throat, you may have picked up a virus. Either way, be kind to your body—and maybe keep some tissues close by.

  • Can Herpes or Chickenpox Trigger Alzheimer’s?

    What Gene Hackman’s death can teach us about brain health

    When news broke recently about the death of legendary actor Gene Hackman and his wife, the headlines were striking. Not just because of who they were, but because of how they died.

    Hackman’s wife reportedly died of hantavirus, a rare infection found mostly in the desert Southwest of the U.S.. Hackman himself died about a week later, with reports citing complications from heart disease and Alzheimer’s.

    But what really caught my attention — as someone who’s worked in infectious disease control for decades — is how these both deaths may have been caused by an infection.

    Can Infections Trigger Alzheimer’s?

    We usually think of Alzheimer’s as a disease of aging, genetics, and bad luck. But over the past few years, scientists have uncovered growing evidence that infections, especially viral infections, may play a role in triggering or accelerating dementia.

    Certain viruses, like herpes simplex (the one that causes cold sores) or varicella zoster (which causes shingles), can linger in the body for years. When reactivated, they may spark inflammation in the brain. That chronic inflammation could damage neurons, interfere with brain function, and set the stage for Alzheimer’s.

    And it’s not just viruses. Even bacteria that cause gum disease have been implicated.

    What Does This Mean for the Rest of Us?

    The story of Gene Hackman’s death is tragic. But it’s also a reminder of how infectious diseases can shape our health in ways we don’t always see.

    Preventing infections and reducing the infectious dose we’re exposed to— by staying up to date on vaccines, practicing good hygiene, and taking care of chronic conditions — is not just about avoiding short-term illness. It may also be part of protecting long-term brain health.

    That’s a connection I think we will be hearing a lot more about in the years to come.

    Read more: https://www.psychologytoday.com/us/blog/fevered-mind/202503/a-surprising-infectious-disease-link-to-gene-hackmans-death

  • How to Think Clearly About Mystery Disease Outbreaks?

    Not every scary disease headline means the next pandemic is here. Here are four questions to ask.

    Every few months, my social media feed fills up with scary headlines about a “mystery disease” or a possible new pandemic. A few weeks ago, it was reports out of Russia — people coughing up blood, testing negative for common viruses, and speculation that this might be a new, unknown pathogen.

    This kind of story has become so common that I think we’re now facing something like an “epidemic of epidemic rumors.” But there’s a way to think more clearly when these stories pop up.

    Questions to Ask About Any New Outbreak

    When I worked at CDC, the very first thing we learned about investigating outbreaks was this: start by confirming the facts.

    Whenever I hear about a potential new disease — whether it’s called “Disease X” or something else — I run through four key questions:

    1. Has the disease actually been confirmed in a lab?

    Early reports are often based on symptoms like fever, cough, or diarrhea — which can be caused by dozens of well-known infections. Until specimens are collected and tested (ideally in a good lab), it’s impossible to know whether this is something new or just something familiar showing up in a new place.

    2. How is it spreading?

    Airborne transmission — meaning the infection passes from one person’s breath to another — is the most concerning. But if transmission requires direct contact, contaminated food or water, or insect bites, the outbreak is much less likely to explode globally.

    3. How severe is it?

    Paradoxically, diseases that kill quickly and severely (like Ebola) often spread less easily than milder diseases like COVID-19 or measles, which allow infected people to walk around and unknowingly infect others.

    4. Do we have tools to fight it?

    Our concern becomes less if we have drugs that can reduce symptoms, reduce infectiousness, and/or cure disease. Similarly, we can be less worried if we have vaccines that can prevent severe illness and reduce infectiousness. If we have neither drugs nor vaccines, we need to be more worried.

    Bottom Line

    Most reports of “mystery illnesses” or “Disease X” turn out to be something we already know how to deal with — like malaria, flu, or a seasonal virus.

    That doesn’t mean we should ignore them. It just means we should approach these stories like a public health detective — looking for facts, not just fear.

    Read more: https://www.healthbeat.org/2025/04/09/disease-x-outbreak-how-to-assess-reports/

  • Should Babies Get the Measles Vaccine Before Age 1?

    Why Some Parents Are Asking This Question Right Now?

    For most of my career in public health, this question rarely came up in the U.S. The routine measles vaccine schedule — first dose at 12 months, second dose at 4 to 6 years — has worked incredibly well for decades because we’ve usually had enough people vaccinated to prevent large outbreaks. The overall force of infection was low.

    But 2025 isn’t a typical year.

    This year, measles is spreading rapidly across the U.S., with hundreds of cases and at least two deaths already reported. It’s the largest outbreak we’ve seen in years — and it’s leaving many parents of babies under age 1 wondering if they should take an extra step to protect their child.

    Can Babies Get the Measles Vaccine Early?

    Yes — in certain situations, babies can safely get their first dose of the MMR vaccine as early as 6 months old.

    This isn’t new advice, but it’s advice that’s become newly relevant. The CDC recommends early vaccination for infants 6 to 11 months old if they live in or are traveling to an area with a measles outbreak.

    There’s just one catch: this early dose doesn’t “count” towards the routine two-dose series. Babies will still need another MMR dose after their first birthday, and again at 4 to 6 years old, to ensure long-term protection.

    Is Early Vaccination Worth It?

    In my view — absolutely, if measles is circulating near you.

    Measles is highly infectious. Because the infectious dose is so low and spreads through the air, the attack rate after exposure to an infected person is extremely high. And it isn’t just a mild childhood illness. It can cause pneumonia, brain inflammation, deafness, blindness, and even death. For babies, whose immune systems are still developing, the risks are even higher.

    Early vaccination is safe. It may not provide as durable protection as shots given later, but in the middle of an outbreak, some protection is far better than none.

    If you’re a parent of an infant, talk to your pediatrician. Ask whether your child qualifies for early vaccination. The stakes are high, but the solution is simple — a shot that saves lives.

    Read more here: https://www.psychologytoday.com/us/blog/fevered-mind/202504/should-babies-get-the-measles-vaccine-before-age-1

  • Bacterial Vaginosis: Time to Treat Men Too

    I had a unique opportunity in my clinic last week to use the results of a new clinical trial to help a patient. An adult woman came in worried about recurrent bacterial vaginosis (BV). She has been treated with antibiotics frequently and wanted to get tested for BV again, even though she was not having symptoms right now. She has been feeling embarassed and irritated by the fishy odor in the past and does not want it to recur. I explained to her that new research indicates that this condition is not solely a concern for her. It’s a problem that her male partner can do something about to prevent her from getting BV again.

    BV is caused by an imbalance in the vaginal bacteria, leading to an overgrowth of harmful bacteria. This shift can result in symptoms like excessive discharge and an unpleasant odor. Traditional treatment involves treating women with antibiotics to restore the balance of good bacteria. Unfortunately, BV often recurs and leads women to use antibiotic pills, antibiotic creams, and chemicals (e.g., boric acid) repeatedly to alter the acidity of their vagina.

    A recent study involved 164 couples where one partner was diagnosed with BV. The male partners were either given a placebo or a combination of oral antibiotics and a topical cream. The results were striking: treating the male partner reduced the likelihood of BV recurrence in women by 63%. This is a classic example of asymptomatic transmission. It underscores the importance of treating both partners when one partner has BV.

    It’s essential for women experiencing BV to ensure their male partners receive appropriate treatment. That’s why I offered to my patient that we can treat her (one) male partner. By treating both partners, we can improve health outcomes and minimize the risk of complications associated with BV.

    Read more at: https://www.psychologytoday.com/us/blog/fevered-mind/202503/bacterial-vaginosis-a-new-understanding-of-transmission

    “By treating both partners, we can improve health outcomes and minimize the risk of complications associated with BV.”

  • Did COVID Measures Go Too Far? It Depends Who You Ask — And Who’s Missing From the Conversation

    Lately, I’ve noticed a growing chorus of people claiming that America’s response to COVID-19 — the shutdowns, the distancing, the masking — went too far.

    And I get why people feel that way. The restrictions were painful, isolating, and disruptive. But here’s my concern: a lot of these conversations are shaped by a cognitive trap known as survivor bias.

    What Is Survivor Bias and How Does It Affect COVID-19 Debates?

    Survivor bias happens when the only voices we hear are from those who made it through an ordeal — while the stories of those who didn’t are absent. In the case of COVID, that’s more than 1.1 million Americans who died. It’s millions more struggling with Long COVID or post-COVID heart problems. It’s also the countless people who never got infected because the measures worked.

    These are the voices we don’t hear enough from in today’s revisionist debates about COVID policy.

    Were COVID Protection Measures Perfect? Of Course Not.

    Every emergency response involves trade-offs. Policies need to be evaluated, mistakes acknowledged, and future plans improved. But I worry that survivor bias leads us to oversimplify what was, in reality, a brutally difficult set of decisions made under enormous uncertainty.

    Business restrictions, behavior change, contact tracing, and vaccine requirements weren’t designed to make life less enjoyable. They were designed to avert illness and save lives — including the lives of people we might not see or know from a virus that spread through aerosols.

    Why Does Survivor Bias Matter for Future Public Health Decisions?

    As we prepare for future health emergencies, we need to resist the temptation to only listen to the loudest voices in the room. We also need to listen to those who can’t speak — because they didn’t survive.

    Public health is about protecting everyone — not just those fortunate enough to make it through unscathed.

    Whose Stories Will We Remember?

    The next time you hear someone say COVID measures went too far, ask yourself: whose story are we missing? And what might they have told us if they were still here?

    Read more at: https://www.psychologytoday.com/us/blog/fevered-mind/202504/who-decides-what-was-too-much-in-the-covid-19-response

  • NIH Cuts Threaten Future of American Medical Innovation

    As a physician and public health expert, I have seen firsthand how transformative US investment in medical research in be. The main engine of that funding has been the National Institutes of Health, which, until recently, had a budget of $40 billion that flows to government, academic, and private industry researchers. It fuels discovery, turns promising ideas into life-saving treatments, and anchors the U.S. as the global leader in biomedical innovation. That’s why I read with particular horror and sadness about how funding changes are already undermining America’s ability to develop the next generation of therapies.

    Why Does NIH Funding Matter for Medical Breakthroughs?

    This isn’t about politics. It’s about patients and the pipeline that brings lab discoveries to their bedside. NIH dollars don’t just pay for pipettes and petri dishes or for researchers to keep busy publishing scientific papers. They pay humans who become the next generation of innovation in medical research, support start-ups especially those spun off from university research labs, and fund the highest risk research that private investors won’t. When the NIH freezes grants or slashes budgets, everything slows. Not enough staff to do the work. No funding for the supplies, equipment, and costs of expensive (and life-saving) clinical trials. Cures delayed.

    What Are the Consequences of the NIH Budget Cuts?

    We saw the power of NIH investment with mRNA vaccine development—millions in early support for the types of research that only government will take a risk on. That research eventually saved millions of lives and counting. When studied in clinical trials, it also gave us critical information about to guide our public health policies, such as the attack rate, secondary attack rate, infectious period, and incubation period in people who had immunity and those who did not.

    Yet now, that kind of forward-thinking investment is under attack. Start-ups tackling mental health, rare diseases in children, cancer treatment, or new antibiotics are stuck in limbo. Talented young scientists are already leaving research entirely because there’s no money to support their work.

    Could the U.S. Lose Its Edge in Biomedical Research?

    The U.S. doesn’t have a monopoly on good ideas. Countries like China are rapidly scaling up their own biotech industries. If we cede this ground, we don’t just lose prestige. We lose jobs. We lose innovation. We lose having access to life-saving treatments developed in the U.S. We lose the chance to lead. And we eventually lose lives.

    What Should Be Done to Protect U.S. Medical Innovation?

    The administration’s mantra is to “Make America Healthy Again.” That requires more, not less, investment in science. Undermining NIH doesn’t just shrink budgets—it shrinks our future.

    If we care about health, competitiveness, or just plain human decency, we need to treat science as the national asset it is. We should be doubling down on NIH, not tearing it down.

  • It’s Time to Clean the Air

    Why is Clean Air Essential for Public Health?

    Clean air is crucial for preventing the spread of infectious diseases, particularly respiratory viruses that can linger in the air.

    As an epidemiologist, I’ve witnessed firsthand how our understanding of disease transmission has evolved, especially during the COVID-19 pandemic. Historically, the focus was primarily on surface cleaning and hand hygiene. This was to reduce transmission through direct contact and fomites. Airborne transmission, disease spread by droplets and aerosols, was often overlooked. However, COVID-19 has highlighted the critical need to prioritize air quality in our public health strategies.

    Airborne viruses, which often also have a low infectious dose, can travel significant distances, making it imperative to ensure that indoor environments are equipped with proper ventilation, air filtration, and disinfection systems. We must advocate for cleaner indoor air just as we have for clean water and safe food, recognizing that the air we breathe plays a vital role in our overall health.

    • Understanding airborne transmission of respiratory viruses
    • Technologies for improving indoor air quality
    • The role of public awareness in health policy

    How Can We Improve Indoor Air Quality?

    Improving indoor air quality requires a multifaceted approach that includes proper ventilation, air filtration, and disinfection.

    To effectively combat airborne diseases, we need to adopt comprehensive strategies that enhance indoor air quality. This includes using high-efficiency particulate air (HEPA) filters in HVAC systems, ensuring adequate ventilation to replace stale air with fresh air, and employing air purifiers in spaces where ventilation is limited. Additionally, public awareness campaigns are essential to educate communities about the importance of clean air and the technologies available to achieve it. As we move forward, it is crucial to integrate these practices into our public health policies and create environments that prioritize the health of individuals and communities alike.

    • Implementing HEPA filtration systems
    • Increasing ventilation in indoor spaces
    • Promoting the use of air purifiers

    What Role Does Political Will Play in Air Quality Initiatives?

    Political will is essential for enacting policies that prioritize clean air in public health initiatives.

    Advocating for cleaner indoor air is not just a matter of science; it requires strong political commitment to implement effective policies and regulations. Policymakers must recognize the importance of air quality in preventing disease and invest in infrastructure that supports clean air initiatives. This includes funding for research, incentives for businesses to adopt air quality improvements, and regulations that mandate air quality standards in public spaces. Building a coalition of public health advocates, scientists, and community leaders can help drive this agenda forward, ensuring that clean air becomes a priority in our health policies.

  • Why I Keep Talking About Measles

    Why Is Measles Still a Public Health Concern?

    Despite being considered a disease of the past, measles remains a critical public health issue that signals the effectiveness of our health systems.

    Measles is often viewed as a resolved threat due to the widespread availability of vaccines; however, it serves as a vital indicator of the functioning of public health systems. Vaccination against measles is one of the most effective public health interventions, second only to access to clean water and sanitation. The unique aspect of measles is that it solely infects humans, meaning its transmission is entirely in our control. If we see rising cases, it indicates a breakdown in our immunization systems and overall public health infrastructure. This disease primarily impacts our most vulnerable populations, including infants and pregnant women, making it imperative that we maintain high vaccination rates. When I observe measles data, I interpret it as a crucial barometer of how effectively we are protecting our communities’ health.

    • The role of vaccines in public health
    • Impact of measles on vulnerable populations
    • Consequences of declining immunization rates

    What Makes Measles So Contagious?

    The highly contagious nature of measles makes it one of the most challenging diseases to contain, especially in populations with low immunization rates.

    Measles is known for its extraordinary contagiousness—one infected person can spread the virus to 90% of the people they come into contact with who are not immune. It has one of the highest basic reproductive numbers of any human pathogen, because of airborne transmission (disease spread by aerosols) and a low infectious dose. This means that even a small drop in vaccination coverage can lead to outbreaks, putting entire communities at risk. The disease preys on the most vulnerable, including infants too young to be vaccinated, young children, and pregnant women. The implications of this are profound; if we cannot effectively manage measles, it raises significant concerns about our ability to handle other infectious diseases. This is why I continue to emphasize the importance of measles vaccination in my discussions and outreach efforts.

    • Understanding the transmission dynamics of measles
    • The importance of herd immunity and reducing the force of infection
    • Strategies for improving vaccination rates

    Why Should We Keep Talking About Measles?

    Continuing the conversation around measles is essential for the ongoing improvement of public health systems.

    Measles is not just a historical footnote; it serves as a critical marker for the health of our public health systems. By continuing to focus on measles, we draw attention to the importance of vaccination and the overall infrastructure necessary for preventing outbreaks. It is my belief that if we can effectively manage measles, we can build resilience against a multitude of other infectious diseases. Therefore, it is my mission to raise awareness, provide insights, and advocate for robust health policies that prioritize vaccination and public health preparedness. I encourage everyone to engage with this topic further through my posts and videos to understand why measles matters for all of us.

  • Why I’m Writing More Now

    Effective communication is more crucial in public health than ever before.

    Effective communication is essential in public health as it helps to inform and educate the public about health threats, ensuring that people understand the risks and the necessary actions to take.

    Throughout my career, I have recognized that clear, consistent communication can bridge the gap between scientific understanding and public perception. The COVID-19 pandemic starkly illustrated the importance of credible voices in guiding the public through complex health information. As we face new challenges in public health, I feel a strong responsibility to amplify these voices and foster a more informed community. The backlash against health measures and the politicization of science have highlighted the need for robust communication strategies that engage citizens and empower them to be proactive about their health.

    • The impact of misinformation on public health responses
    • The role of public health leaders in crisis communication
    • Strategies for engaging communities in health initiatives

    How can we build a more resilient public health system?

    Building a more resilient public health system requires collaboration, investment, and an engaged citizenry that understands health issues.

    As I reflect on the current state of our health systems, it is clear that resilience comes from not only having the right resources but also fostering a culture of communication and transparency. By actively engaging with the public through various platforms, we can demystify health policies and encourage community involvement. My mission extends beyond mere advocacy; it is about creating a movement where every individual feels empowered to contribute to public health discussions and actions. Together, we can advocate for policies that prioritize health investments and combat misinformation, ensuring that our systems are equipped to handle future challenges.

    • Importance of community involvement in health policy
    • Investment in public health infrastructure, such as infectious disease surveillance systems
    • Investment in public health education
    • Developing clear communication strategies to combat misinformation

    What role does personal commitment play in public health advocacy?

    Personal commitment is vital in public health advocacy as it drives individuals to take action and inspire others to do the same.

    For me, this mission is deeply personal. My experiences have shaped my understanding of the critical need for a proactive and informed public. I believe that when individuals are motivated by a personal connection to health issues, they are more likely to engage and advocate for change. This personal commitment fuels my desire to expand my communication efforts through writing, videos, and other platforms, aiming to cultivate a community of informed citizens who are passionate about public health. Together, we can work towards a healthier future, armed with knowledge and a shared sense of responsibility.