CConcerns about the dangers of mosquito-borne viruses are growing after the first New Yorker since 2015 to contract Eastern equine encephalomyelitis (EEE) died last weekend, New York Governor Kathy Hochul announced Monday.
“Eastern equine encephalomyelitis is different this year. While we typically see these mosquitoes in two to three counties each year, so far this year they have been in 15 counties and scattered throughout New York State,” State Health Officer James McDonald said in a news release Monday. “There is no commercially available vaccine for humans for this life-threatening mosquito-borne disease and it must be taken seriously. Mosquitoes, once a plague, are now a threat.”
The virus, transmitted through the bite of an infected mosquito, is on the rise throughout the Northeast. Coastal towns in Massachusetts have closed parks and playgrounds to better protect residents, amid concerns about the disease’s deadliness. According to the Centers for Disease Control and Prevention (CDC), about 30% of people who contract a severe case of EEE die, although that number can be even higher in some years.
“The peak period for these cases is currently between July and September,” says Erin Staples, a medical epidemiologist at the CDC.
In 2024, only 10 people were infected with EEE, but the data was last updated on September 17 and does not yet include the New York case.
What is EEE?
Eastern equine encephalomyelitis virus is a rare disease transmitted by several species of mosquitoes. Experts say that while cases are rare and most people who contract the disease are asymptomatic, the most severe cases can be fatal.
“In individuals who survive Eastern equine encephalomyelitis, we often see that people have long-term virologic deficits. So it’s definitely one of our more serious arbovirus infections,” says Jennifer White, director of the Vector-Borne Disease Program at the New York State Department of Health.
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The virus causes inflammation in the brain, which, according to Staples, can trigger other symptoms such as fever, headache, vomiting, weakness, etc. In more severe cases, sufferers can also experience seizures and fall into a coma.
Because EEE is a virus, there is no treatment for those infected. And unlike other mosquito-borne viruses, the Eastern equine encephalomyelitis virus can affect people of all ages.
Experts stress that caution is all the more important because there is no treatment for the virus. “There are no specific drugs or antivirals for viral diseases transmitted to humans through mosquito or tick bites,” says Staples. “The doctor can prescribe medications for more subtle symptoms … (but) for severe diseases like Eastern equine encephalomyelitis, patients will need to be hospitalized, and the health system and doctors will provide supportive care to try to get through the acute illness.”
Why are electrical and electronic devices more common in the Northeast?
EEE is found in mosquitoes living in hard-water freshwater swamps in the northeastern United States, but it is also found in the Midwest, coastal regions of the East, and the Gulf Coast.
Cases involving electrical and electronic equipment have been reported this year in New Jersey, Massachusetts, Rhode Island, New Hampshire, New York, Vermont and Wisconsin.
Staples said it’s difficult to predict when arbovirus diseases will be on the rise because the spread of the disease can depend on several factors, including the spread of the disease to other animals, such as birds and horses. The highest number of cases ever recorded in a year was 38 in 2019, according to an article in the National Library of Medicine Journal.
“If there’s less or more water, there are hurricanes or other things, that can obviously affect the ecosystem that the birds live in. The CDC worked with New Jersey a few years ago to figure out why things were changing with the EEE. Part of it was human usage patterns and changing ecology that was affecting where the virus was,” says Staples.
How to protect yourself from electrical and electronic devices
The CDC urges people to listen to their local and state authorities to best protect themselves from electrical and electronic equipment.
In New York, Hochul called on state authorities to increase access to insect repellent at state parks and facilities and to increase public education about the disease. Local health departments in the state are also expected to reduce park hours during what they consider to be peak mosquito activity times. White says officials are particularly concerned about EEE this year because there have been reports of the virus in mosquitoes, emus and horses in 15 counties. “What made this year so unprecedented is the geographic range in which we’re seeing EEE this year,” White says. “That’s raised everyone’s concern a little bit, and we’re also seeing high levels of West Nile virus — we’re seeing more human cases than ever before.”
The best way to protect yourself is to protect your skin to avoid bites. “That means wearing long sleeves and long pants at dawn and dusk when mosquitoes are most active,” White says, also mentioning the importance of using insect repellent. Staples adds that people should make sure to use EPA-recommended brands and check that their window screens are intact. Since water attracts mosquitoes, it’s also important to avoid standing water in your yard.
“Basically, you should make your property and any place with standing water inhospitable to mosquitoes,” says Staples. “If you have a birdbath, tip it over before mosquito larvae have a chance to develop into adult mosquitoes.”
“We are not telling people not to go outside, but when you are outside, you should take steps to prevent mosquito-borne disease and protect yourself from mosquito bites whenever possible,” she adds.
