### New York Confronts Rise in Eastern Equine Encephalitis (EEE) Incidents Amid Mosquito Boom
New York is presently dealing with an unexpected increase in mosquitoes that transmit the lethal Eastern Equine Encephalitis (EEE) virus, which has already led to a rare death and compelled state authorities to declare an “imminent threat” to public health. This year, the virus has been identified in mosquitoes across 15 counties, a notable rise from the usual two or three counties affected each year.
State Health Commissioner James McDonald underscored the seriousness of the issue, stating, “Eastern equine encephalitis is distinct this year.” He recommended that New Yorkers adopt precautions, such as utilizing insect repellents, donning long-sleeved attire, and eliminating stagnant water around residences to prevent mosquito breeding sites. McDonald also indicated that mosquitoes would continue to pose a danger until the area undergoes multiple nights of sub-zero temperatures.
On September 20, New York confirmed its first EEE-related fatality since 2015, occurring in Ulster County. This unfortunate incident prompted a Declaration of an Imminent Threat to Public Health, issued by McDonald, along with statewide preventive measures announced by Governor Kathy Hochul. The disease is exceptionally rare in New York, with just 12 recorded cases between 1971 and 2024, seven of which were deadly.
### What is Eastern Equine Encephalitis (EEE)?
EEE is an uncommon yet fatal mosquito-borne virus that mainly affects birds but can also infect humans and other animals, especially horses. The virus is most commonly found in the northeastern United States, typically appearing from mid-June to early October, before colder weather eliminates mosquito populations.
The virus is especially deadly for horses, with mortality rates reaching 90%. In humans, the illness is considerably rarer, with an average of only 11 cases reported annually in the U.S., according to the Centers for Disease Control and Prevention (CDC). Nonetheless, when the virus does infect people, the consequences can be severe. Approximately 4–5% of individuals bitten by an infected mosquito develop symptoms, and those who do are at high risk for serious illness or death.
### Symptoms and Risks
For individuals who develop EEE, the virus initially triggers nonspecific symptoms such as fever, headache, joint pain, nausea, and vomiting. In extreme cases, the virus can invade the brain, leading to encephalitis (inflammation of the brain), which may result in seizures, altered mental states, and other neurological issues. Children under 15 and adults over 50 are at the greatest risk of severe illness.
The death rate for severe EEE instances is around 30%, though this statistic can vary. For example, in Massachusetts, about 50% of EEE cases have resulted in death. Survivors of the illness frequently endure lasting neurological damage, and some may die within a few years due to complications. Presently, there is no vaccine or specific treatment for EEE, making prevention through mosquito control and personal protective strategies essential.
### Nationwide Context
While New York is witnessing an atypical surge in EEE-positive mosquitoes, the total number of cases across the U.S. remains relatively stable. As of this year, the CDC has recorded 10 cases from six states, including Massachusetts, Vermont, New Jersey, Rhode Island, Wisconsin, and New Hampshire. The New York case would increase the total to 11, which aligns with the national average.
The death in New York marks the second confirmed EEE-related fatality in the U.S. this year. In August, New Hampshire reported the death of a previously healthy 41-year-old man from Hampstead, who succumbed to the virus. Massachusetts, which has recorded four EEE cases this year, even advised residents in certain towns to adhere to an evening curfew to diminish the risk of mosquito bites.
### Historical Perspective
EEE is an uncommon disease, but it has generated significant concern in recent times. The highest occurrence of cases in a single year took place in 2019, when 38 cases were documented across the U.S. From 2003 to 2023, the virus has remained rather rare, but its high mortality rate and serious long-term effects on survivors present a significant public health issue.
### Preventive Measures
Given the absence of a vaccine or specific treatment for EEE, prevention is critical. Health officials advise the following measures to lower the risk of mosquito bites:
1. **Use Insect Repellents**: Apply EPA-registered insect repellents containing DEET, picaridin, or oil of lemon eucalyptus.
2. **Wear Protective Clothing**: Donning long-sleeved shirts, long pants, and socks can minimize skin exposure to mosquitoes.
3. **Eliminate Standing Water**: Since mosquitoes breed in stagnant water, it’s important to remove any standing water around homes, like in flowerpots.
