Healthbeat

New York health update: Covid, vaccine recommendations, West Nile virus, a Legionella outbreak

2025-09-18T15:22:58+00:00

This article originally appeared at Your Local Epidemiologist New York. Sign up for the YLE NY newsletter here. Public health, explained: Sign up to receive Healthbeat’s free New York City newsletter here.

Infectious disease ‘weather report’

Ugh, even epidemiologists get Covid.

Recently, my partner and I both felt like we had “allergies” — itchy eyes, mildly scratchy throats, and some lung irritation. It was so mild that at first we didn’t even think to test. When we finally did, his turned positive instantly. Mine never did. But, based on the timing of symptoms, I’m pretty sure I caught it first and then cleared the infection by the time we tested.

Consider this my firsthand evidence that Covid activity is elevated in New York, and the data agree.

Wastewater data is showing an upward trend. I’ll note that the latest data is usually unstable as all the sites submit data, but it stabilizes after about two weeks. This likely explains what looks like a big drop near the end of August.

New York state Covid-19 wastewater activity levels.

That said, the recent rise in wastewater concentrations aligns with increased hospitalizations.

Everything else is quiet still:

Flu: Outpatient visits for flu-like illness haven’t started rising in New York yet, but I’m keeping a close eye on it. In other parts of the country, numbers have started to climb.

RSV: Still quiet.

I was planning on getting my fall Covid booster soon, but after just getting over Covid, I’m deciding to wait. Data show that after a Covid infection, delaying immunization by about ~6 months can increase its effectiveness. (YLE national covered the timing of Covid vaccines here). I’m getting my flu shot soon though!

Speaking of immunizations …

Updates to routine immunization eligibility are expected this week

There’s a lot happening right now around vaccine access and eligibility, both for Covid and routine immunizations.

Last week we covered New York’s steps to keep Covid-19 vaccination accessible, including executive and standing orders that allow pharmacists to vaccinate anyone over age 3 without a prescription. In practice, you may still need to check “yes” to the eligibility question on pharmacy websites when scheduling, but New York pharmacists have the authority to vaccinate you whether or not you have an underlying condition.

CVS appointment scheduler questions. Check “yes” that you would like to receive a Covid vaccine and are eligible.

Today, the Advisory Committee on Immunization Practices is starting a two-day meeting to vote on Covid-19, hepatitis B, and MMRV (measles, mumps, rubella, varicella) vaccine recommendations. There is a very real possibility that ACIP will vote against recommending some of them for certain ages. Such a decision would truly be unprecedented given overwhelming evidence supporting their safety and effectiveness. If that happens, the availability of these vaccines will be reduced.

I do expect New York state will step in to protect these vaccines. Gov. Kathy Hochul has issued an executive order and standing order to safeguard Covid-19 vaccine access (we covered it here), and I anticipate something similar if ACIP votes against hepatitis B or MMRV. Even so, a quick executive order can’t erase the confusion. Potentially conflicting messaging from federal and state departments will undoubtedly create uncertainty and confusion, making it harder for some to get vaccinated.

While I don’t think that Covid vaccines should be removed, most people in New York have a buffer of community immunity, and access to Covid vaccines through the executive order. If recommendations change, it will have the greatest impact on those who don’t have immunity, like young children, pregnant women, and people who are immunocompromised. But hepatitis B and MMRV are a different story. Removing these vaccines sets us back in the progress we’ve made in protecting babies, and puts kids and vulnerable populations at risk of serious, preventable diseases.

That’s why now it’s more important than ever to stay informed, and remember that vaccines remain one of the safest, most effective tools to protect babies, children, and everyone else from severe and preventable illness. I’ll be back next week with the implications for New Yorkers after we know with certainty what the ACIP votes will be.

We are in peak West Nile virus season

New York is seeing West Nile virus activity across the state. This is typical — September is when we often see the highest West Nile virus infections. This most recent data show mosquitoes tested positive in:

Erie
Nassau
Orange
Rockland
Suffolk
NYC: all five boroughs

A few mosquitoes in Oswego County also tested positive for Eastern Equine Encephalitis virus, which is rare but more dangerous than West Nile. So far, there have been 26 human West Nile cases across the state, and no cases of EEE.

In New York, it’s too early to tell if this is a normal year or not because this is the time of the year when West Nile cases typically really pick up.

Nationally, West Nile is 40% higher than normal. In New York, we’re getting close to last year’s total West Nile-positive mosquito pools (1,638 so far, compared to 2,167 last year), and the season usually runs until the first few freezes in November. So it’s too soon to tell how bad this year will be.

New York counties continue to use mosquito control to reduce risk. Many have conducted or plan to conduct aerial insecticide spraying, where a plane disperses chemicals to kill mosquitoes or prevent breeding. (You can check your local health department website for local schedules.) There are recent or upcoming events for New York City (Brooklyn and Queens this week).

To minimize exposure to insecticides during spraying:

Stay indoors
Bring pets inside
Close windows

Legionnaires’ disease in Westchester

Yes, another outbreak. This time Westchester County is investigating a spike in Legionnaires’ disease. So far this year:

38 people have been diagnosed
2 people have died

This is an increase — last year there were 24 cases total in the county. Across the state, excluding New York City, we are at 383 cases so far for this year.

Officials recently confirmed a cluster of five cases in Yonkers and said that cooling towers are being inspected in response. But we don’t know where the cases reside or where they could have been exposed. I’m concerned that not enough information is being shared, or shared quickly enough. Knowing which neighborhoods or ZIP codes are affected helps us assess personal risk. And clear, timely, and consistent communication from public health departments is essential, not just for managing outbreaks, but for building and maintaining community trust.

Legionnaires’ disease is a serious lung infection caused by breathing in tiny water droplets containing the Legionella bacteria. Symptoms usually start 2-10 days after exposure and can include:

Cough
Fever
Chills
Shortness of breath
Muscle aches
Diarrhea

Most healthy people exposed won’t get sick. Those at higher risk are adults over age 50, smokers, and people with chronic lung disease, diabetes, cancer, or weakened immune systems.

It’s not spread person-to-person because it doesn’t infect cells the same way a respiratory virus does (like Covid). You also can’t usually get it from drinking water — water rarely enters the lungs while drinking, and stomach acid likely kills it when ingested. In New York, and especially around New York City, outbreaks with cases across communities (like this one) are typically linked to cooling towers, which are separate from residential plumbing. This means that your tap water is not a risk.

Why has there been so much Legionnaires’ this summer?

The increase in Westchester Legionnaires’ cases follows the large outbreak in Central Harlem, where seven people died and 114 were diagnosed. We covered it here. And Legionnaires’ disease has been increasing nationally.

National Legionnaires’ disease rates have been increasing, though data after 2022 have not yet been published.

Several factors may be driving the increase in Legionnaires’ cases this summer in New York:

Warmer temperatures and higher humidity can promote bacterial growth in water systems. This has been one of the hottest summers on record for many parts of New York.
Potential lapses in regulation and inspection can allow Legionella to grow undetected, especially when buildings aren’t maintaining cooling towers properly. In New York, building owners are legally required to test cooling towers for Legionella every 90 days. During the Central Harlem outbreak, Gothamist reported that most of the towers linked to the outbreak were behind on testing and hadn’t been inspected by the city in over a year.
Increased awareness can lead to more identified cases. When large outbreaks happen, media and public health alerts can increase the chance that milder cases are caught. Doctors might be more on the lookout and the public may be paying closer attention to their symptoms, which are good things.
Climate change may also be playing a role, as longer and hotter warm seasons can create more opportunities for Legionella growth.

Grandparents for vaccines

Think Moms Against Drunk Driving, but for polio and measles. A new grassroots group of grandparents just launched to protect kids’ vaccine access. They’re driven by lived experience — remembering when these diseases ran rampant — and are elevating their stories.

Fueled by personal experiences, they are asking for support and stories. Learn more and join them here.

What else you need to know

Measles in NYC

The NYC Department of Health and Mental Hygiene has confirmed two adult cases of measles in Manhattan. They are investigating potential exposures at two unnamed restaurants in SOHO and the Lower East Side, and contacting those who may have been exposed. Reminder — if you are fully vaccinated, you are well protected.

Blue-green algae in Onondaga

Onondaga County has issued an advisory for a harmful algal bloom at Skaneateles Lake. These blooms, caused by overgrowth of blue-green algae (cyanobacteria), can cause skin rashes, stomach upset, or more serious illness if swallowed or inhaled. Before swimming at lakes or ponds, check local advisories and pay attention to posted signs. If you or your pet were exposed, rinse off really well and seek medical care if symptoms develop.

Bottom line

You’re all caught up on New York public health news this week!

Love,

Your NY Epi

Dr. Marisa Donnelly, PhD, is an epidemiologist, science communicator, and public health advocate. She specializes in infectious diseases, outbreak response, and emerging health threats. She has led multiple outbreak investigations at the California Department of Public Health and served as an Epidemic Intelligence Service Officer at the Centers for Disease Control and Prevention. Donnelly is also an epidemiologist at Biobot Analytics, where she works at the forefront of wastewater-based disease surveillance.

It’s peak bug season in New York: Covid, measles, mosquitoes are thriving

2025-08-29T19:40:14+00:00

Before we begin, I want to touch on some news we received late Wednesday — Centers for Disease Control and Prevention Director Dr. Susan Monarez was abruptly removed, just weeks after the Senate swore her in. Immediately following, three of CDC’s most senior leaders (Drs. Deb Houry, Daniel Jernigan, and Demetre Daskalakis) resigned in protest, citing increased political interference. (You can read Demetre’s powerful resignation letter here.)

This type of leadership implosion at the CDC is not normal. And it definitely widens the vacuum in federal public health guidance that’s been growing over the past year. This instability at our nation’s top public health agency should concern us all. It raises questions about whom we should turn to in the face of health threats, whether it’s seasonal respiratory viruses or the next pandemic. I’m still wrapping my head around this, but I’ll be back with updates as it further unfolds.

For now, let’s get back to this week’s dose.

It’s peak bug season and Covid-19, measles, and mosquitoes are thriving across the state. But it’s not just the bugs: Recent events, from a tragic bus crash in upstate New York to the close of a Legionnaires’ outbreak, show how fragile our systems can be, and how directly that fragility impacts our health.

Here’s what you need to know this week.

Covid-19 ‘weather report’ and an update on fall vaccine availability and FDA approval

All regions of New York show that Covid-19 hospitalizations are elevated. Hospitalizations are still substantially lower than they were this time last year, but are increasing. Given what’s happening in other states, like Florida and Hawaii, we expect increases to continue.

New York City Covid-19 hospitalizations across race and ethnicity groups.

Risk is not spread evenly, and these groups are seeing the highest rates of hospitalization:

Central New York and the Finger Lakes have the highest rates, when adjusting for population.
75 and older age group has higher rates according to data we have in New York City. (We expect it to be the same elsewhere.)
Hispanic and Latino people have about twice the rate of hospitalization compared to white people. This likely reflects longstanding structural inequities, including greater exposure to risk (from factors such as relying on public transportation or working in more public-facing jobs), more crowded housing, and limitations in health care access, rather than differences in underlying health alone.

What does this mean for you? The best thing to do is wear a mask in crowded indoor areas. I’m going to wear one on the train and at the airport, for example. The Food and Drug Administration just approved fall Covid-19 vaccines, with some significant changes to who will be eligible. YLE National answered several questions on fall Covid-19 vaccines here.

Reflections on the Legionnaires’ outbreak

First, the good news: the Legionnaires’ outbreak in Central Harlem is ending, with fewer and fewer cases being reported after the identification of contaminated cooling towers.

Now, the bad news: Rarely in public health is something random. This outbreak revealed deep cracks in prevention systems in the area:

Cooling tower monitoring. As I explained a few weeks ago, building owners are legally required to test cooling towers for Legionella every 90 days, and the city aims to inspect each tower at least once per year. But, according to Gothamist, most towers linked to this outbreak were behind on testing and hadn’t been inspected by the city in over a year. And despite increases in funding, the number of inspectors has dropped by more than 30% over the past three years. Enforcement and staffing need attention.
Health equity. Central Harlem, a predominantly low-income and Black neighborhood, has high risk factors for Legionnaires’ disease among residents, like asthma and diabetes. The city should prioritize enforcement and staffing of inspections in Central Harlem and the surrounding areas, in particular.
Climate change. Legionella bacteria thrive in warm climates. We should expect Legionella to become more common with climate change and plan accordingly to stay ahead of it.
Risk communication. In the posts where I covered this outbreak, I tried to communicate that risk was low for most people. However, risk is unevenly distributed, and local communications about the outbreak fell short. Many in Central Harlem feared leaving their homes, and workers said they weren’t given adequate info to keep them healthy. We need timely and transparent communication, including guidance for those at greatest risk, that is grounded in trust and not just broad reassurance.

An outbreak of this size signals that the system failed somewhere upstream. Six people died, and dozens were hospitalized. Everyone deserves to step outside and breathe clean air without fear, regardless of ZIP code.

Mosquito-borne threats: malaria and West Nile

New Jersey, in partnership with the CDC, is investigating a case of malaria in a Morris County resident who may have been infected locally — the patient had not traveled internationally.

For local transmission to occur, two conditions must be met: 1. the right mosquito species (Anopheles), which is commonly found in New Jersey, New York, and most other states, and 2. the malaria parasite itself, which is usually absent here.

If confirmed, this would be big news. Every year, New Jersey reports around 100 malaria cases, almost all among travelers returning from abroad. The last time the state saw a locally acquired case was in 1988. The risk to the public is very low, but public health officials are likely moving quickly to test mosquitoes, treat the patient, and prevent any spread.

The results of mosquito testing will tell us if any local mosquitoes are positive for malaria, but the bottom line is that risk is very low. The best thing you can do is avoid mosquito bites:

Wear repellent (DEET, picaridin), especially at dawn and dusk.
Wear long sleeves.
Dump standing water around your home.

Conveniently, the same recommendations apply for preventing West Nile virus. On that note, the first two human cases of West Nile virus in New York City this year were detected in Queens last week. Now’s the time to break out that repellent!

Tragic Erie bus accident and blood supply

On Aug. 22, a tour bus returning from Niagara Falls overturned on Interstate 90 near Pembroke, killing five adults and injuring dozens. Hospitals quickly drew on local blood supplies, prompting ConnectLife, the area’s primary blood bank serving Erie County Medical Center and Kaleida Health hospitals, to issue an emergency appeal for blood donations.

Smaller cities often lack the blood reserve capacity of large, urban centers. This means mass casualty events can drain the supply overnight, especially for rare blood types or platelets, which have shorter shelf lives. While the emergency need for blood following this accident has likely passed, it’s a sobering reminder that routine blood donations are critical for ensuring readiness for unexpected medical crises.

Here’s where you can donate blood:

New York City: New York Blood Center.
Rest of New York state: American Red Cross Blood Donation Centers.

Measles in New Jersey

The New Jersey health department confirmed a measles case in Hudson County, linked to contact with a case from outside the state. Key details remain unclear:

Did the exposure/transmission occur in a public place?
Was the non-N.J. resident case associated with international travel or the result of domestic transmission?
Was either patient vaccinated?

What we do know: The Hudson County case rode PATH and the light rail during commuting hours while potentially infectious. Anyone on those routes may have been exposed. If you are fully vaccinated for measles, you are well protected. If you develop symptoms, contact your health care provider before arriving in person at the doctor’s office.

What else to know this week

Coming up: Free back-to-school vaccine clinics in Buffalo

The Erie County Department of Health is partnering with the University of Buffalo School of Nursing to provide free back-to-school vaccine clinics for Buffalo public school students. These free clinics are taking place as follows:

Sept. 12, 10 a.m.-2 p.m. at the Buffalo Public School 95 Waterfront, 95 Fourth St.
Sept. 18, 2 p.m.-6 p.m. at the Buffalo Public School 309 East Community High School, 820 Northampton.
Sept. 19, 2 p.m.-6 p.m. at the Buffalo Public School 363/415 Lewis J. Bennett/Middle Early College, 2885 Main St.

The vaccines offered include all required school immunizations: DTap/DTP/Tdap/Td; polio; MMR, hepatitis B, varicella, meningococcal, Hib, and PCV (pneumococcal). Students must be up to date on vaccines by Sept. 17 to remain in school, as required by New York State Public Health Law 2164.

Bottom line

From Covid and measles to malaria, Legionnaires’, and even blood shortages, this week’s headlines share a theme: Local preparedness matters. Global diseases, chronic inequities, and unexpected crises all land in our neighborhoods. Staying healthy depends on how much our systems — and our communities — are ready to respond.

Love,

Your NY Epi

West Nile virus, Covid, hand foot and mouth disease in New York — and tragedy at CDC

2025-08-15T16:00:00+00:00

This week’s dose is heavier than usual. I’ll cover the typical summer health updates (West Nile virus, Covid, and algal blooms) but am also sharing some reflections on the tragedy at the Centers for Disease Control and Prevention last week: a mass shooting. As a former CDC employee, this one shook me.

But before we jump in, we’re hiring! If you or someone you know is passionate about public health communication, apply here for our Managing Editor position.

West Nile Virus is being detected across New York state

We continue to see West Nile virus pick up across New York, which is typical for this time of year. This week, mosquitoes tested positive in Erie, Nassau, Onondaga, Rockland, Suffolk, and Westchester counties. In New York City, mosquitoes carrying the virus were found in all five boroughs. New York, Richmond, Bronx, Queens, and Kings counties also reported positive mosquitoes. A small number tested positive for Eastern Equine Encephalitis virus, which is rare but more dangerous than West Nile.

New York counties are ramping up mosquito control. Many have conducted or plan to conduct aerial insecticide spraying, where a plane disperses chemicals to kill mosquitoes or prevent breeding. (You can check your local health department website for local schedules.) Recent or upcoming events include Cattaraugus County (Aug 17–23), Onondaga County (last week), and New York City (Brooklyn and Queens this week).

If spraying is scheduled in your community, you can reduce exposure to chemicals by:

Staying indoors
Bringing pets inside
Closing windows

Covid continues to increase, though slowly

Due to delays on the CDC wastewater dashboard, most New York sites aren’t reporting public wastewater data, so I’m focusing on clinical data to understand trends in Covid activity.

All regions of New York, except for Mohawk Valley and North Country, show that Covid hospitalizations are increasing. Hospitalizations are still substantially lower than they were this time last year.

New York state Covid-19 hospitalizations.

If you are feeling sick and take an at-home rapid test, make sure to check the expiration date. Many tests had their expiration dates extended, but they are now approaching those dates. This guide by the North Carolina Department of Health has good instructions on how to check.

Reflections on the tragic CDC shooting

It was the last day of the summer course. The culmination of a month of daily, intensive training for this year’s class of Epidemic Intelligence Service Officers, a program I went through myself. EIS officers are CDC disease detectives, trained to investigate and respond to outbreaks and other urgent public health threats in the United States and around the world. Instead of celebrating, they spent hours sheltering in place on the CDC’s campus as a single shooter sent over 180 rounds of bullets into the windows of four buildings. Many are now afraid to even display their CDC parking decals on their cars for fear of being targeted in public.

There have been more than 260 mass shootings this year in the United States, nine of them in New York, and the effects of each one ripple across individual lives and entire communities. This week, I’m worrying about the long reach of this attack on my friends and colleagues at the CDC and on our entire public health system.

I have more questions than answers. Who will pick up the torch in the next pandemic if our frontline people burn out or leave? Where does this leave us in 10 or 20 years, or in the wake of another health emergency? Why is health leadership so silent on this? What does it say about our country if our government employees are afraid to go to work?

For those in public health here in New York, or elsewhere, I see you. You aren’t alone. Feel free to drop a comment or directly reply to this email; let’s process it together. For everyone else, check in on your people in public health. Thank them for their service.

I’m also donating to the fund for the family of the officer who lost his life protecting the CDC from the shooting. You can join me here: https://give.cdcfoundation.org/give/715122#!/donation/checkout.

What else you need to know this week

Algal blooms: Some New York freshwater beaches — like Sylvan Beach, Verona Beach Park, and Oneida Shores — were closed this week due to harmful algal blooms. These blooms, caused by overgrowth of blue-green algae (cyanobacteria), can cause skin rashes, stomach upset, or more serious illness if swallowed or inhaled. Before swimming at lakes or ponds, check local advisories, and pay attention to posted signs. If you or your pet were exposed, rinse off really well and seek medical care if symptoms develop.

Rabies vaccine campaign in Erie County: From Aug. 13 to 23, the U.S. Department of Agriculture will be dropping fish-scented bait packets containing oral rabies vaccine across Erie County by helicopter. When raccoons and other animals eat the bait, they become immunized against rabies. If you find a packet, don’t touch it. If you must handle it, wash your hands immediately. Keep an eye on kids and pets when outdoors during distribution, and keep pets leashed to keep them from eating the bait. See the distribution map here.

Rabies vaccine bait.

Hand, foot, and mouth disease in New York: Some doctors in New York are reporting that this year is an exceptionally bad year for hand, foot, and mouth disease. So if you feel like this is tearing through your kid’s daycare or preschool, you aren’t alone. HFM is a super common and very contagious virus that mainly affects children under 5. It’s usually mild, but symptoms can include fever, mouth sores, and skin rash. There isn’t a ton to be done about it. The best things to do are to keep things clean (wash hands and surfaces) and talk to your child’s health care provider if they develop symptoms.

Bottom line

This week we’re reminded of how vulnerable public health can be, and how much it relies on people who care about it deeply. If you are in public health, know that we are with you and are so so grateful for your work. If you’re not in public health, it’s a good time to check in on those who are.

Love,

Your NY Epi

Legionnaires’ disease outbreak grows in Harlem. Rabies, West Nile on the rise. What you need to know.

2025-08-08T15:00:00+00:00

We’re seeing movement on multiple infectious disease fronts in New York this week. The Legionnaires’ disease outbreak in Harlem has more than doubled. Rabies is elevated in some counties. And across the state, West Nile virus is rising with mosquito activity. This week’s post will cover what these mean for your health, and how to reduce your risk. Let’s dive in.

Legionnaires’ outbreak grows

The cluster of Legionnaires’ disease in Harlem we reported on last week continues to grow. As of Thursday, there were 73 cases, including three deaths. Affected ZIP codes are: 10027, 10030, 10035, 10037, and 10039. The risk to most is low, but if you live or work around these ZIP codes and have flu-like symptoms, it’s important to see a health care provider immediately for possible antibiotic treatment. If you do not have a health care provider, visit NYC Health + Hospitals.

Legionnaires’ disease symptoms include:

Cough
Fever
Chills
Muscle aches
Shortness of breath

Most people exposed to Legionella bacteria won’t show symptoms, but the bacteria is particularly risky for people who are over 50, people who smoke or who have chronic lung disease, and those with weakened immune systems. The most recent New York City Legionnaires’ report showed that among people infected in 2019-22, more than 90% had at least one chronic medical condition, and more than 50% were previous or current smokers. The most commonly cited medical conditions were diabetes and lung disease.

For outbreaks like this in New York City, the culprit is most likely a cooling tower. These usually sit on roofs and use water evaporation to cool the building. When bacteria-containing mist from a contaminated cooling tower drifts down, people can breathe it in and get infected. This means that residents in these ZIP codes can continue to drink tap water, bathe, shower, cook, and use their air conditioners.

That’s because cooling towers and drinking water tanks are different systems — it’s not the same water.

We’ve had several Legionella outbreaks here linked to cooling towers previously. Every year, there are hundreds of cases detected in New York City.

During the pandemic, cases actually declined compared to the previous couple of years. Masking and less movement around the city probably reduced exposure to mist from cooling towers, where Legionella can grow.

In 2015, one of the biggest outbreaks of Legionnaire’s disease in the United States was linked to a single cooling tower in the Bronx. That tower was responsible for 135 cases and 16 deaths.

In New York City, Legionnaires’ disease tends to be more common in Northern Manhattan and the Bronx. The reasons aren’t totally understood, but it’s likely due to a mix of factors, including lower maintenance of building systems like cooling towers (often tied to income and infrastructure disparities) and higher rates of chronic health conditions like diabetes, which can increase risk of severe infection.

So, how can we prevent outbreaks?

In New York, the best way to prevent outbreaks is to test and treat cooling towers. Legionella bacteria is actually quite common in the environment, and a positive test doesn’t always mean there will be an outbreak. Still, New York has a system. Under state law, all cooling towers must be:

Registered with the state
Tested for bacteria
Cleaned and disinfected after testing
Maintained under a long-term management plan

These requirements apply to all cleaning towers, including residential buildings, schools, office buildings, and businesses. When Legionella is detected, the tower must be cleaned and retested until it meets safety standards.

What does this mean for me?

While Legionella is common in the environment, most people exposed won’t get sick. But when conditions are right, and there are vulnerable groups living or working close to sources, exposure can lead to serious illness. If you live or work in one of the affected ZIP codes and have or develop flu symptoms, seek medical care as soon as possible. Early detection, proper maintenance, and rapid public health investigation are key.

Rabies in Nassau

Rabies is increasing in some New York communities. Nassau County just declared rabies an “imminent threat” in the county because of the increase in recent detections. Over the past year, 25 wild animals, including raccoons and feral cats, have tested positive for the virus in Nassau County — a sharp increase since it was declared eradicated in the county in 2016. In March, Suffolk County also noted an increase in rabies in raccoons.

In 2024, Westchester and Erie counties had the highest rabies detections of New York counties.

Rabies, nearly 100% fatal for humans, circulates in the wild animals around us. And while increases in rabies may sound scary, there are practical steps we can implement that make risk to humans pretty low.

What you can do

Ensure that your pets are up to date on rabies vaccines — in New York, state law requires it. All New York counties offer free rabies vaccination clinics. For more information, contact your local health department.
Do not touch or get close to wild animals, including feral cats. If you are bitten, immediately wash the wound with soap and water and contact your medical provider. Advise children to immediately tell an adult if they are bitten or scratched by an animal.
If you see a wild animal that doesn’t look well, or you encounter a dead animal, contact your local health department or 311 if you are in New York City. Rabies symptoms in animals include tiredness, confusion, difficulty moving, aggression, drooling, and chewing objects like wood, soil, or stones.

Getting vaccinated is crucial if a wild animal bites you. I learned that firsthand in college when a monkey bit me while I was traveling — and I’m thankful I got the shots.

Question grab bag: A reader asks, ‘What’s the risk of rabies from a dog bite? Do we treat bites from wild and domestic animals differently?’

Great question. When we talk about rabies in the United States, most of the risk surrounds wild animals, especially bats, raccoons, skunks, and foxes. Domestic dogs and cats can carry rabies, but it’s actually extremely rare in the United States. In New York, because vaccination is mandatory, rabies in domestic cats and dogs is nearly unheard of.

With that said, when a person is bitten by an animal, there are multiple factors that go into determining the best course of action for rabies treatment, including:

Vaccination status of the animal (if known)
Type of animal (wild vs. domestic)
Location of the bite: Bites to the head or neck or deeper bites can increase risk because they are closer to the central nervous system
If the animal can be quarantined and observed for illness
Local rabies levels and alerts (some areas have more local circulation)

The bottom line is that whenever someone is bitten by an animal, they need to contact a medical provider and public health as soon as possible to discuss the best course of action.

West Nile virus increasing in Long Island and rest of state

West Nile virus continues to heat up this summer with more mosquito detections across the state and in New York City.

West Nile virus detections in New York. (Figure from the New York State Department of Health. Annotations by YLE.)

Now is the time to be wearing mosquito repellent at dawn and dusk, or consider wearing long sleeves if it’s not too hot. Annoyingly, I had a mosquito fly into my loose pants last week and bite me on the shins, so I’m switching to repellent. Also, dump standing water around your home — it’s the perfect breeding habitat for these pests.

Bottom line

You’re all caught up! See you next week. :)

Love,

Your New York Epi

How to avoid ticks and mosquitos this spring in New York City

2025-05-14T12:54:50+00:00

Warm weather is finally here in New York, and it’s the perfect time to get outside. But we’re not the only ones enjoying the sun — mosquitoes, ticks, and pollen are becoming more active, too. A little awareness goes a long way in staying healthy while soaking up the warmer days ahead. But first, some good news.

Good news: New York will provide school meals for all kids

New York just became the ninth state to pass universal school meals. Starting in the fall, 2.7 million students across New York state will receive free breakfast and lunch each day at school. This is an incredible public health victory, propelled by a silver lining of the pandemic: increased knowledge of the importance of school meals for children.

As early as 2015, hundreds of New York City schools began giving free meals to all students, regardless of socioeconomic status. A 2021 study by the Urban Institute found that New York City students who qualified for free or reduced-price meals were more willing to participate in school meals once their school implemented free meals for all, and that there was less bullying and fighting schoolwide. Free school meals for all reduced the stigma and had positive effects for all students, regardless of their socioeconomic status.

This new statewide initiative will open the doors for students across the state and ensure that no kid goes hungry while at school.

Mosquitoes: Why to avoid them and how

From now until roughly November, when temperatures drop, we can expect mosquitoes to hang around. This month, New York City started treating standing water for mosquito larvae, which helps reduce the mosquito population and disease risk. Spraying usually happens later in the summer when mosquitoes are even more active. (We’ll update you when that’s scheduled.)

Most mosquitoes do not carry pathogens that can hurt us. Among those that do, the most common is West Nile Virus. In 2024, 100 human WNV cases were reported across New York state, including in New York City. While most people who get WNV won’t show symptoms, it can be more dangerous for those over 60 years old or who have immunocompromising conditions.

The best thing you can do is avoid mosquito bites:

Wear EPA-approved mosquito repellent outside, especially during peak mosquito activity time: dawn and dusk. If you are using sunscreen, apply sunscreen first and insect repellent second.
Avoid being outside when mosquitoes are most active (the morning and evening)—but this can be really hard.
If it’s not too hot, long sleeves and long pants can protect against bites.
Dump standing water (think flower/plant saucers, buckets, fountains, toys that have been sitting outside, etc.) to eliminate mosquito habitats.

Ticks: Why to avoid them and how

We are in peak tick season in the Northeast, and this season is looking worse than last.

In New York, black-legged ticks (aka deer ticks) are the most common carriers of pathogens. These tiny ticks can transmit Lyme disease and other infections. Cases typically rise in the warmer months, especially from May through August, when ticks are most active.

Lyme disease is the most common tickborne illness in the United States — and New York reports some of the highest numbers in the country with more than 9,000 cases annually. Symptoms usually start with fever, fatigue, and a bullseye rash, though not everyone gets the rash or can see it if skin is darker — thanks, PHunkle, for highlighting this diagnosis challenge!

While rural areas like the Finger Lakes and Central New York have long been hotspots, ticks are increasingly found in parks and green spaces across all five New York City boroughs. Even city dwellers aren’t immune.

Protecting yourself and family means avoiding ticks:

Use repellent that contains 20% or more DEET, picaridin, or IR3535 on exposed skin.
Treat clothing and gear with products containing 0.5% permethrin.
Walk in the center of trails and avoid brushing against tall plants.
Do tick checks after spending time outdoors. For kids, especially check under arms, in and around ears, in the belly button, and in their hair.
Toss your clothes in a hot dryer for 10 minutes to kill any hidden hitchhikers.
Treat dogs for ticks. Dogs are very susceptible to tick bites and may also bring ticks into your home.

If you find a tick attached to your skin, remove it promptly with tweezers and monitor for symptoms. Early treatment is key to preventing severe illness.

New York pollen: high

Pollen has struck me this week, and my nose is like a mini Niagara Falls. 🤧🌊 The data confirm what my nose tells me — New York pollen counts are high or medium-high throughout the state this week.

Allergies are a nuisance, but they can also be dangerous for those with asthma. In New York City, emergency department visits for asthma spike when pollen counts increase.

About 1 in 12 children in New York and an additional 1.5 million adults have asthma. For those with asthma, tracking pollen levels and reducing exposure can help with prevention. Talking with your provider about managing asthma symptoms during allergy season is also a good idea.

Dr. Zachary Rubin, an allergist and immunologist, has a helpful post on managing and dealing with allergies.

Bottom line

You’re all caught up! And a belated happy Mother’s Day to all the moms out there — you are deeply appreciated. My own mom, a public school science teacher, inspired my love of science and health, and her unwavering support carried me through. Thanks, Mom!

Love,

Your NY Epi

California dengue cases prompt swift response from public health officials

2024-11-12T16:32:34+00:00

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Jason Farned and his team at the San Gabriel Valley Mosquito and Vector Control District had spent years preparing for the likely arrival of dengue, a dangerous virus typically found in tropical climates outside the mainland United States.

They’d watched nervously as invasive Aedes mosquito species that can carry the virus appeared in Los Angeles about a decade ago and began to spread, likely introduced by international trade and enticed to stay by a warming climate that makes it easier for mosquitoes to thrive.

Then, in October 2023, an email came from the Pasadena Public Health Department: A person in the city had contracted California’s first-known case of dengue from a local mosquito.

“When it happens in real time, real life, you know, it is very different,” Farned said. “There’s no room for error here. We have to be quick and effective in identifying the most at-risk areas and responding.”

Across California, public health and pest control authorities are facing a new reality as the Aedes mosquitoes bring the threat of dengue and potentially other tropical diseases, such as chikungunya, Zika, and yellow fever, that were once of concern only to international travelers.

So far this year, authorities have identified at least 13 cases of locally acquired dengue, up from two in 2023, with 11 in Los Angeles County and two in the San Diego area. The Aedes mosquitoes spread the disease by biting an infected person and then biting a previously uninfected person.

Illness prevention centers on mosquito control

Mosquito-borne viral illnesses, chiefly malaria, have long been a scourge in many tropical regions, and preventive measures focus mainly on controlling the mosquitoes. The Aedes mosquitoes, known for their aggressive, daytime biting, are now present in at least 24 California counties. They breed in water, in as little as a capful.

“When these locally acquired cases occur, … we want to act on them pretty quickly so that it does not become an endemic infection in our region,” said Aiman Halai, director of the Los Angeles County Department of Public Health’s Vector-Borne Disease Unit.

California officials are hoping to beat back dengue by expanding mosquito surveillance, developing detailed response plans for mosquito outbreaks and human infections, and improving data sharing across agencies. They’re also going door to door in neighborhoods to remove standing water sources and apply pesticides. Residents are advised to wear bug repellent and long-sleeved clothing and control mosquitoes around their homes to prevent biting and infection.

Some vector control districts — local agencies charged with managing disease-bearing insects and other animals — are even growing their own sterile mosquitoes to release into the wild to reduce local Aedes populations.

What you need to know about mosquitoes and West Nile virus

Outside California, locally acquired dengue cases have occurred in Arizona, Florida, Hawaii, and Texas. In March, Puerto Rico declared a public health emergency after a spike in cases there, where dengue is endemic. Meanwhile, worldwide dengue cases are on track to more than double this year, with 12.3 million documented through August, up from 6.5 million in 2023, according to the World Health Organization.

Most people who get dengue have no symptoms, but about 1 in 4 become ill. A mild case can feel like the flu and usually dissipates within a week, but about 5% of those infected with dengue become very sick, with symptoms that can include internal bleeding, shock, and organ failure, and the most severe cases can be fatal. People infected a second time are at especially high risk.

There is no specific medication to treat dengue. Japanese pharmaceutical company Takeda developed a vaccine that has won approval in Europe and elsewhere, though it withdrew an application to the U.S. Food and Drug Administration last year, saying it could not provide data requested by the agency. A vaccine developed in Brazil could soon be approved for use in that country. But the only FDA-approved vaccine is authorized only for children in narrow circumstances and will soon go out of production.

At the San Gabriel Valley Mosquito and Vector Control District, one of five agencies tasked with mosquito control across Los Angeles County, public health workers have put together an Aedes and dengue response plan based on updated guidance from the state.

When they discover a case, they identify all the properties and public spaces within 150 meters — roughly the distance an Aedes mosquito can fly — and then go door to door, removing standing water, where mosquitoes can breed; applying pesticides from backpacks or trucks; and educating residents about the risk of dengue and how to protect themselves. District officials also set traps to catch mosquitoes so they can figure out their prevalence and test them for dengue.

West Nile virus shows up early in NYC; travelers bring dengue

Since local dengue cases began to appear, the district has gotten more efficient in implementing its response plan, district manager Farned said. All full-time and seasonal staff members — about 40 people — have been trained in a variety of tasks, such as door-to-door education and coming in during off-hours to answer phones, Farned said.

While vector control teams respond to cases, separate teams from the Los Angeles County Public Health Department go door to door in the affected neighborhood when they determine that a dengue case was locally acquired, surveying residents and offering free dengue testing to try to identify others who may be infected.

Additionally, the department has been sending alerts to local health providers, advising them to be on the lookout for possible dengue cases and test for it when suspected, even among patients who haven’t traveled to a place where dengue is endemic. This advice follows a national alert put out by the Centers for Disease Control and Prevention in June. Health authorities are also emphasizing that people who travel to locations with dengue should continue to wear mosquito repellent when they get home, to reduce the risk of spreading the disease to local mosquitoes.

As happened during the Covid-19 pandemic, mistrust of public health authorities can make outreach challenging for health and pest control teams in some neighborhoods, officials said.

Pest control officers can seek a warrant to enter and treat a property for mosquitoes if a homeowner refuses to give access, said Jeremy Wittie, a former president and the legislative committee chair for the Mosquito and Vector Control Association of California, which represents the more than 70 mosquito and vector control agencies in California. This is easier in districts such as his, the Coachella Valley Mosquito and Vector Control District, that have warrants giving officials standing permission to enter a property after 24 hours without needing to ask a judge.

Aerial spraying, mosquito sterilization combat threat

In counties such as Santa Clara, where Aedes mosquitoes first appeared in 2022 but have yet to establish themselves, officials hope to suppress the threat with stepped-up surveillance, speedy eradication efforts, and more public outreach. Santa Clara County Vector Control District Manager Nayer Zahiri said the aim was to eliminate Aedes but acknowledged the climate conditions that encourage the mosquitoes’ spread are “totally out of our control.”

In some counties with pervasive mosquito problems, including San Diego, San Joaquin, and Stanislaus, officials have sprayed pesticides from planes or helicopters to address spikes in local mosquito populations, Wittie said. These sprayings typically aim to control the larvae of a different type of mosquito, Culex, that can spread West Nile virus and which — unlike the Aedes species, which thrive in urban habitats — are found in harder-to-reach rural environments, Wittie said.

Aerial spraying hasn’t been deployed to address the recent dengue outbreaks, which are in more urban environments where spraying from trucks is a better option, Wittie said. Drones are another option that some vector control authorities are exploring.

Some districts are experimenting with the decades-old sterile insect technique, commonly used for other pests such as fruit and screwworm flies, in which males are sterilized with radiation and then released to mate, resulting in eggs that don’t hatch. (Female mosquitoes are separated from the males before sterilization and not released. Only the females bite).

Ultimately, the public will have to take the mosquito threat more seriously and contribute to prevention efforts, Wittie said. “This mosquito is going to be here to stay, unfortunately. I hope it kind of wakes people up and pushes them to be part of that solution.”

This article was produced by KFF Health News, which publishes California Healthline, an editorially independent service of the California Health Care Foundation. KFF Health News is Healthbeat’s national reporting partner.

Mosquitoes linger as fall arrives

2024-10-09T11:00:00+00:00

Sign up for Your Local Epidemiologist New York and get Dr. Marisa Donnelly’s community public health forecast in your inbox a day early.

As the leaves change, we say goodbye to summer, but at least one thing remains for a couple more weeks — mosquitoes.

Yes, mosquitoes are annoying, but they can also pose serious health risks for New Yorkers. It’s worth grabbing mosquito spray for a couple more weeks.

Here’s what’s going on with mosquitoes in New York (state and city) and especially the two diseases making the news.

New York state reports human case of EEE

This is the first case in the state since 2015. The case was identified in Ulster County and the patient died.

Eastern Equine Encephalitis is a virus transmitted by the bite of a certain species of mosquito. Thankfully, most people infected with EEE won’t have any symptoms. But for those who develop symptoms, the illness can be severe and involve inflammation of the brain (encephalitis) and spinal cord (meningitis).

About one-third of people who develop severe illness die.
There is no specific treatment available.
People over the age 50 or younger than 15 are at greatest risk.

EEE rare in New York, but may be more active this year

Since 1971, only 12 human cases have been identified in the state, including the most recent one. Of these patients, seven died. A human case of EEE is a significant event.

There are some signs that this year might be worse than recent years. Typically, two or three New York counties detect EEE annually by testing mosquitoes, horses, and birds. This year, though, 14 counties have detected it all across the state. And this isn’t because there is more testing this year; the level of testing is similar to last year.

Counties in solid blue have detected EEE mosquitoes, with Ulster County detecting positive mosquitoes and a human case. Striped blue counties are testing mosquitoes for EEE but have not detected it. Data from the New York state mosquito activity report

West Nile virus is circulating in New York City and state

West Nile virus is also a disease spread by some mosquitoes and is more common than EEE.

So far, 42 human cases have been detected in New York state (excluding New York City) and 35 cases in New York City. Compared to the past few years, this has been a normal year.

West Nile virus cases in New York state, excluding New York City.

WNV has been detected in most of the New York counties that are testing for it. On the map below, solid light or dark orange and brown counties have had WNV detections in humans, mosquitoes, horses, or birds.

Counties where humans, mosquitoes, horses, or birds have tested positive for West Nile virus (solid light or dark orange and brown).

If we zoom in on New York City, we are also in the average range of WNV human cases. Over the past 10 years, the total number of annual cases has ranged from 6 to 46.

West Nile virus cases in New York City.

WNV-positive mosquitoes are almost everywhere in the city. Below, regions in blue are where West Nile virus has been detected in the past two weeks (light blue) and earlier this season (dark blue).

The number of WNV cases in the city is similar to the rest of the state (35 vs. 42) for two reasons:

The high population density in the city — more people are there to get bitten.
There is a lot of WNV activity. When adjusting for population size, Richmond (Staten Island) and Queens counties have some of the highest WNV case rates in the state.

Most people infected with WNV will not have symptoms or will have very mild illness. However, those over 60 years old or with immunocompromising conditions are at higher risk for severe illness, which can include inflammation of the brain (encephalitis) and spinal cord (meningitis), or muscle weakness or paralysis (acute flaccid paralysis).

What is being done to prevent more human cases?

A lot!

First, public health departments randomly test mosquitoes. Mosquitoes are collected in traps, identified in the lab, and tested in groups (for efficiency). We’ve been doing this for decades, and although imperfect, it gives us a good view of risk.

With consistent positives (in mosquitoes or humans), vector control units will then go to these areas and spray mosquito repellent in mass. Several factors go into the decision to spray:

Mosquito density and species
Persistence of the virus
Time of year
Proximity to human populations

While mosquito spraying is safe for humans and pets, if spraying is happening in your neighborhood and you have asthma or other respiratory conditions, it’s a good idea to try and stay inside during the spraying time.

There are no mosquito spraying events scheduled for New York City in the near future. You can check for schedule updates here. For spraying events in other areas of New York state, check with your local public health or mosquito control departments.

On top of ongoing mosquito control, New York state health commissioners issued a Declaration of Imminent Threat to Public Health in response to the Ulster County EEE case. This move:

Frees up additional state resources to go toward reducing mosquito-borne diseases, including more public outreach and strengthening public health surveillance to detect human cases and positive mosquitoes
Increases mosquito spraying throughout the state to reduce the adult mosquito population
Provides free insect repellent to visitors at New York state parks and campgrounds

When will the mosquitoes leave?

Mosquitoes can only transmit these diseases when it’s warm. Once average temperatures drop to around 60°F, mosquito biology makes transmission much more difficult. It likely won’t be that cool consistently in New York until late October or early November, so until that happens, we should all be diligent about protecting ourselves from mosquitoes.

To avoid contracting WNV or EEE, the best thing you can do is avoid mosquito bites:

Wear EPA approved mosquito repellent when outside and especially during peak-mosquito activity time: dawn and dusk.
Avoid being outside when mosquitoes are most active (the morning and evening) — but this can be really hard.
Dump standing water (think flower/plant saucers, buckets, fountains, toys that have been sitting outside, etc.) to eliminate mosquito habitats.

Bottom line

We are still in mosquito season. Because mosquitoes can carry some nasty diseases, keep that mosquito spray close for a few more weeks!.

Love,

Your Local Epidemiologist

Dr. Marisa Donnelly, a senior epidemiologist with wastewater monitoring company Biobot Analytics, has worked in applied public health for over a decade, specializing in infectious diseases and emerging public health threats. She holds a PhD in epidemiology and has led multiple outbreak investigations, including at the California Department of Public Health and as an Epidemic Intelligence Service Officer at the Centers for Disease Control and Prevention. Marisa has conducted research in Peru, focusing on dengue and Zika viruses and the mosquitoes that spread them. She is Healthbeat’s contributing epidemiologist for New York in partnership with Your Local Epidemiologist, a Healthbeat supporter. She lives in New York City. Marisa can be reached at mdonnelly@healthbeat.org.

West Nile virus a ‘moderate concern’ in Atlanta, with 7 cases reported

2024-09-09T19:27:26+00:00

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An increase in West Nile virus cases in Georgia – from two in August to seven last week – has spurred concern, as county health departments take steps to control mosquitoes, which spread the disease.

Nationwide, 377 cases have been reported this year, according to data from the U.S. Centers for Disease Control and Prevention.

“There’s clearly high risk circulating in the environment among the mosquitoes here … When there’s a cluster of cases, the likelihood for additional cases is higher than an average year,” said Emory University infectious disease expert Dr. Matthew Collins, who considers the disease a “moderate concern” in metro Atlanta.

Collins urged people to take precautions against mosquito bites, but said there’s no reason to panic.

“Driving in Atlanta is probably much higher risk than getting West Nile in Atlanta,” Collins said.

Two human cases of the virus have been identified in Fulton County, with one each in DeKalb, Cherokee, Hall, Richmond, and Chatham counties as of Sept. 3, according to the CDC.

Of the seven, four cases have been the more serious “neuroinvasive” type, which can affect a patient’s brain or spinal cord and lead to confusion, severe headache or loss of consciousness.

Officials doing West Nile virus surveillance

The Georgia Department of Public Health tracks West Nile virus by identifying birds, horses, and mosquitoes that test positive, which helps determine the areas where people are most at risk, spokesperson Nancy Nydam said.

Local public health departments focus on preventing mosquito breeding, but each county uses a slightly different approach.

In DeKalb County, public officials do not spray for mosquitoes but rather use larvicide. That is environmentally friendly and prevents mosquito larvae from becoming biting adults, spokesperson Eric Nickens said.

Photos help East Point show community’s challenges, but also joys

In Fulton County, if West Nile virus is detected in mosquitoes, officials will visit all residents within a quarter-mile of the area to urge precautions. Fulton uses insecticide spraying and larvicide to try to control mosquitoes, spokesperson Darryl Carver said.

“In Georgia, mosquito season lasts into October and sometimes into November, depending on weather conditions. As long as mosquitoes are active, and we know [West Nile virus] is circulating, elevated risk exists,” Nydam said.

Virus goes from birds to mosquitoes

West Nile is spread to humans by mosquitoes, typically Culex mosquitoes that become infected when they bite infected birds. The mosquitoes can then transmit the disease to people, horses, and other mammals, according to the CDC.

People are “dead-end hosts,” according to the CDC. An infected human will not pass the disease on to a mosquito if bitten. However, the disease can be transmitted from one human to another through blood transfusion or organ transplantation, as well as from mothers to babies through pregnancy, delivery or breastfeeding.

West Nile virus was first identified in the United States in New York City in 1999. It is named after the West Nile region of Uganda, where it was originally discovered in 1937.

The spread of West Nile is likely affected by climate change, Collins said. But it’s difficult to draw a direct line between increased temperatures and increased incidence of the disease. Rather, there are “multiple factors” that include the location of bird and mosquito populations, temperature and rain.

Severe cases of West Nile virus are rare

Many people infected with West Nile virus feel no or mild symptoms, and those cases are likely to go unreported, Collins said. Other people may have more moderate symptoms like rash, fever, headache, an upset stomach or diarrhea that will last for a few days and then subside.

West Nile virus cases reported in New York City

The “neuroinvasive” forms, which can cause paralysis, are rarer and more likely to develop in elderly people or those with other health conditions, Collins said.

About two-thirds of cases reported so far this year — 255 of 377 — have been neuroinvasive, according to CDC data. Four of Georgia’s cases have been neuroinvasive.

Testing for the disease is “not great,” Collins said. A simple blood draw can show evidence of past infection but may not indicate infection at the time of the test.

The most definitive diagnosis comes from testing spinal fluid obtained through a lumbar puncture, he said.

Strongest defense: Avoid mosquito bites

There is no commercially available vaccine or treatment for West Nile virus, beyond supportive care, which could include attempting to cool the body in the case of very high fever and breathing support if needed.

Preventing mosquito bites is the strongest line of defense, Collins and the state Department of Public Health emphasized.

Steps people to prevent bites include:

Limiting exposure at dusk and dawn, when mosquitoes are more likely to bite
Wearing longer-sleeved clothes and pants to reduce skin exposure
Using insect repellent with the chemical DEET
Ensuring that doors, windows and screens are tightly closed so that mosquitoes cannot come indoors
Emptying containers, including outdoor pools and buckets, that contain standing water where mosquitoes can breed.

Insect repellents with the chemical DEET are safe, Collins said.

Rebecca Grapevine is a reporter covering public health in Atlanta for Healthbeat. Contact Rebecca at rgrapevine@healthbeat.org.

Healthbeat's New York reporter discusses West Nile virus on WNYC

2024-08-27T19:21:17+00:00

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Healthbeat New York reporter Eliza Fawcett joined “The Brian Lehrer Show” on WNYC on Tuesday to give a public health update on several viral threats.

Fawcett’s recent reporting has focused on cases of West Nile virus in the city and what you need to know about the risk amid peak mosquito season.

“The best way to protect against it is to avoid being bitten by mosquitoes,” Fawcett said.

The city has been spraying neighborhoods with pesticides to mitigate the risk of West Nile virus.

Lehrer and Fawcett also discussed HIV, mpox and Covid in the city.

New Covid vaccines have been approved by the Food and Drug Administration and will be available soon. When people should get them depends on their personal risk factors — and whether they were recently infected during this summer’s spike in cases.

Eliza Fawcett is a reporter covering public health in New York City for Healthbeat. Contact Eliza at efawcett@healthbeat.org.

West Nile virus: What you need to know about the mosquito-borne illness

2024-08-26T19:01:12+00:00

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Human cases of West Nile virus have been reported throughout the United States this year. The virus, which is primarily spread through the bite of an infected mosquito, typically leads to asymptomatic or mild disease. In rare cases, however, the disease can be severe or even fatal.

Dr. Anthony Fauci, one of America’s most prominent infectious disease experts, was recently infected with the virus. The former director of the National Institute of Allergy and Infectious Diseases was hospitalized with a case of West Nile virus this month and is recovering at home, the New York Times reported.

Here’s what you need to know about the virus.

What is West Nile virus?

West Nile virus is the leading cause of mosquito-borne disease in the continental United States, according to the Centers for Disease Control and Prevention.

The virus is primarily transmitted to humans when mosquitoes feed on infected birds and then bite people. In very rare cases, West Nile virus is transmitted from person to person through blood transfusion and organ transplantation, or from a mother to her baby, according to the CDC.

There are no vaccines to prevent West Nile virus, and there is no treatment for it, although health care providers can help relieve patients’ symptoms.

Most West Nile infections are asymptomatic. About 1 in 5 people who are infected develop West Nile fever, the mild form of the disease, according to the CDC. Other symptoms can include headaches, weakness, muscle aches, joint stiffness, gastrointestinal issues, and rashes.

About 1 in 150 infected people develop a more severe form of the disease, West Nile neuroinvasive disease, according to the CDC. People 60 years and older or those with weakened immune systems are at increased risk for the neuroinvasive disease, which can include encephalitis, meningitis and acute flaccid paralysis (severe muscle weakness), and can be fatal.

Where is West Nile virus circulating?

At least 216 cases of West Nile virus disease in humans have been reported in 31 states this year as of of Aug. 20, according to the CDC. Of those cases, 142 have been cases of West Nile virus neuroinvasive disease.

Nationwide, Texas leads the count of West Nile virus human disease cases, with 37 cases as of Aug. 20. About 20 states have reported a handful of cases.

The New York City Department of Health and Mental Hygiene reported the city’s first human cases of West Nile virus last week. As of Monday, the Health Department has reported six cases of West Nile neuroinvasive disease and one case of West Nile fever. The Health Department has also reported three cases of West Nile virus among blood donors.

The number of mosquito pools — groups of up to 50 mosquitoes that the Health Department traps and tests — has more than doubled in the past month, to 1,413 positive pools across the five boroughs. The city appears on its way to surpassing its record high number of West Nile virus detections — 1,555 positive pools reported in 2022.

Georgia has reported two cases of West Nile virus disease in humans so far this year.

What can you do to prevent West Nile virus?

The best way to prevent West Nile virus is to avoid getting mosquito bites.

The CDC recommends using insect repellent, wearing long-sleeved shirts and pants, using screens on windows and doors and eliminating standing water, which can become breeding grounds for mosquitoes.

In New York City, August and September are the peak periods of activity for mosquitoes with West Nile virus.

During the summer, the Health Department sprays pesticides in neighborhoods throughout the city to reduce mosquito activity. Residents can reference the city’s pesticide spraying schedule online.

Property owners in the city are responsible for removing standing water, and violations in public and private locations can be reported to 311 from April through October.

Eliza Fawcett is a reporter covering public health in New York City for Healthbeat. Contact Eliza at efawcett@healthbeat.org.

New York City reports year's first human cases of West Nile virus

Mosquito season: West Nile virus shows up early, travelers bring dengue

New York City reports the year’s first human cases of West Nile virus

2024-08-19T21:53:23+00:00

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The New York City Department of Health and Mental Hygiene reported the year’s first human cases of West Nile virus, in four city residents, on Monday.

One person was diagnosed with West Nile fever and three others were hospitalized with West Nile neuroinvasive disease — a rare and serious condition — beginning in late July, the Health Department said. The four people with West Nile virus disease live in Manhattan and Queens.

The virus was also detected in the blood donations of three city residents, and the Health Department is investigating two possible cases of West Nile virus disease in the Bronx.

Health commissioner Dr. Ashwin Vasan said in a statement that the department continues to treat marshy areas and conduct mosquito spraying. Vasan also emphasized measures residents can take to keep themselves safe.

“Using an EPA-registered insect repellent is one very important tool, especially when outside at dusk and dawn, when the types of mosquitoes that transmit West Nile virus are most active,” he said. “You can also stop mosquitoes from laying eggs and reproducing in the water by emptying outdoor containers that hold water or calling 311 if you see standing water that you cannot empty.”

August and September are the peak periods of activity for mosquitoes with West Nile virus in New York City.

Mosquito pools — groups of up to 50 mosquitoes that the Health Department traps and tests — that are positive for West Nile virus have been reported in all five boroughs. This summer, the Health Department first detected the virus in the city’s mosquito population on June 5, the earliest identification on record.

The Health Department reported a total of 1,286 positive mosquito pools across the city as of Friday, a significant jump from the 703 positive pools reported in late July. At this point last summer, the city had reported 569 positive pools, according to the Health Department.

The New York State Department of Health reported the first statewide human case of West Nile virus earlier this month, in Suffolk County on Long Island.

Mosquito season: West Nile virus shows up early; travelers bring dengue

The vast majority of West Nile infections are asymptomatic. West Nile fever, the mild form of the disease, is characterized by headaches, weakness, muscle aches, joint stiffness, gastrointestinal issues, and rashes.

Less than 1% of infections result in West Nile neuroinvasive disease, the severe form of the disease. People 60 years and older or those with weakened immune systems are at increased risk for the neuroinvasive disease, which can include encephalitis, meningitis and acute flaccid paralysis (severe muscle weakness), and can be fatal.

Every year, New York City sees significant fluctuations in its annual West Nile virus cases, but climate change may lead to increased mosquito activity, Dr. Yesim Tozan, an assistant professor of global and environmental health at the NYU School of Global Public Health, told Healthbeat earlier this month.

In 2022, New York City hit a record high of 1,555 positive mosquito pools and 36 diagnoses of West Nile neuroinvasive disease. Last year, the Health Department reported 1,146 positive mosquito pools and 31 cases of West Nile neuroinvasive disease.

Over the past decade, an average of 17 city residents have been diagnosed with West Nile neuroinvasive disease per year, with a median age of 62 years and a case fatality rate of 10%, according to the Health Department.

Eliza Fawcett is a reporter covering public health in New York City for Healthbeat. Contact Eliza at efawcett@healthbeat.org.

Mosquito season: West Nile virus shows up early; travelers bring dengue

2024-08-08T16:04:08+00:00

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The New York City Health Department has identified West Nile virus in mosquitoes throughout the city, and there’s growing concern about cases of dengue, another mosquito-borne disease, among travelers returning to New York.

There have been no confirmed human infections of West Nile virus in the city or state as of late July, but the city Health Department has reported 703 positive results in mosquito pools across all five boroughs.

In 2022, the city hit a record high of 1,555 positive mosquito pools and 36 diagnoses of West Nile neuroinvasive disease. Last year, the Health Department reported 1,146 positive mosquito pools and 31 cases of West Nile neuroinvasive disease.

The vast majority of West Nile virus infections are subclinical or asymptomatic, according to the Health Department. Symptoms of West Nile fever, or mild disease, include headache, weakness, muscle aches and joint stiffness, gastrointestinal issues and a rash. Less than 1% of infections lead to West Nile neuroinvasive disease, which includes encephalitis, meningitis, or acute flaccid paralysis (severe muscle weakness), and can be fatal.

This summer, the Health Department first detected West Nile virus in the city’s mosquito population on June 5, the earliest identification on record, according to an advisory. But early detection doesn’t necessarily mean a worse year for outbreaks, said Dr. Nicholas DeFelice, an associate professor of environmental medicine and climate science at the Icahn School of Medicine at Mount Sinai, whose research focuses on forecasting diseases including West Nile.

“Every year is different. There’s a lot of moving parts to it, and a lot of things that need to line up well for spillover events to occur,” DeFelice said, referring to the cross-species transmission of the virus.

In New York City, mosquitoes with West Nile virus are present from July through October, with peak activity in August and September. This month marks a “critical point” in the transmission cycle of the virus, when it’s most important to wear mosquito repellent, DeFelice said.

“During this time of the year, the thing that you can do is wear bug spray when you go out,” he said. “Dawn and dusk is when the mosquito that transmits West Nile bites.”

The Health Department also encourages New Yorkers to eliminate standing water around their homes, which can become breeding grounds for mosquitoes.

Climate change may increase risk

The first cases of West Nile virus in the United States were identified in New York City in the summer of 1999, when Dr. Deborah Asnis, an infectious disease specialist in Queens, alerted the city health department about strange symptoms in two of her patients. As the outbreak spread in the city, seven people died and dozens of others fell sick.

In the 25 years since, New York has seen significant fluctuations in annual West Nile virus cases. But climate change could lead to increased mosquito activity, particularly given the city’s temperate climate, said Dr. Yesim Tozan, an assistant professor of global and environmental health at the NYU School of Global Public Health, who researches infectious disease prevention and control.

Climate change increases the risk of human exposure to the virus, as warmer temperatures accelerate mosquito development, biting rates, and disease incubation periods, according to the U.S. Environmental Protection Agency.

Still, it’s hard to know precisely how climate change will shape the transmission of mosquito-borne diseases, DeFelice said. While warmer, wetter conditions might encourage transmission, extreme heat waves could also kill off mosquito populations, he said.

Tozan stressed the importance of collective responsibility when it comes to mitigating outbreaks, from the city’s pesticide-spraying efforts to New Yorkers using bug spray and eliminating standing water.

“There are various points, in this big, complex cycle that is embedded in the environment, where we could go and do things to decrease this transmission force,” she said.

New York, Florida lead dengue count

The United States is also facing an increase in dengue cases among travelers returning from countries where the mosquito-borne viral disease is endemic. Outbreaks of dengue frequently occur in the Caribbean, Central America, South America, Southeast Asia and the Pacific Islands. Earlier this year, Puerto Rico declared a public health emergency after recording a rapid rise in dengue cases.

New York and Florida lead the dengue case count among the 50 states, according to data from the U.S. Centers for Disease Control and Prevention. All of New York’s cases are from returning travelers, not local transmission.

Travelers to countries where dengue is endemic should inform themselves about the risk before departure and take care to protect against mosquito bites while visiting, Tozan said. Swift diagnosis and treatment of the disease is key, she added. Symptoms of dengue may include a fever, aches and pains, nausea, and a rash, according to the CDC. Severe cases can be life-threatening.

In a June alert about the increased risk of dengue among travelers, the Health Department noted that a local outbreak was unlikely. Aedes aegypti, the type of mosquito that primarily transmits dengue, is not typically found in the city, although Aedes albopictus, a close relative, is.

There remains a chance that a viral disease like dengue could start to spread locally, particularly if ideal conditions for rain, temperature and infectious reservoirs are met, Tozan said.

“It is a real possibility,” she said. “It’s just that it may not necessarily cause very big outbreaks, but it will jump around through these chance encounters.”

Eliza Fawcett is a reporter covering public health in New York City for Healthbeat. Contact Eliza at efawcett@healthbeat.org.