Eastern Equine Encephalitis Confirmed in Mosquito Pools in Onondaga and Oswego Counties

New York State Department of Health Reminds New Yorkers to Protect Themselves Against Mosquito-Borne Diseases

ALBANY, N.Y. (August 8, 2018) - The New York State Department of Health is advising New Yorkers to take personal protective measures to avoid mosquito bites, after confirming the presence of Eastern Equine Encephalitis Virus (EEE) in mosquitoes in some areas in Onondaga and Oswego Counties.

"Through our partnership with county health departments, we have learned that mosquito pools in Onondaga and Oswego counties have tested positive for Eastern Equine Encephalitis Virus," said State Health Commissioner Dr. Howard Zucker."To help protect the residents in these counties I have issued an Imminent Threat to Public Health designation which financially aids the localities with prevention measures."

EEE is a rare, but extremely serious viral disease spread by mosquitoes that can affect people and horses. People of all ages are susceptible to infection, but people over 50 and younger than 15 are at greatest risk for acquiring the virus. While most people bitten by an infected mosquito will not develop any symptoms, severe cases begin with the sudden onset of headache, high fever, chills and vomiting. The illness may then progress into disorientation, seizures, encephalitis and coma. Approximately a third of patients who develop EEE die, while many patients who survive EEE experience neurologic impairment.There have been no human cases of EEE to date this year.Since 1971 there have been 11 confirmed human cases in New York State, the most recent (3) being in 2015.

There is no commercially available human vaccine for EEE, so the best way to protect yourself is to keep mosquitoes from biting you. One of the best ways to do this is to take steps to reduce the number of mosquitoes around your home or property, including eliminating standing water in yards.

Repellents also provide protection against tick and mosquito bites. The federal Centers for Disease Control and Prevention (CDC) recommend choosing a repellent that contains DEET, IR3535, or oil of lemon eucalyptus for use on skin. Clothing and gear, such as boots, pants, socks and tents, can be treated with products containing permethrin. (Permethrin should not be used on skin.) Treated clothing or gear remains protective through several washings. Pre-treated clothing is also available and remains protective for up to 70 washings. For all repellents, follow the label directions and apply in small amounts, avoiding contact with the eyes, nose or mouth. Use only small amounts when applying repellents on children.

Onondaga County Health Commissioner Dr. Indu Gupta said,"The Onondaga County Health Department is making preparations to conduct aerial spraying of the Cicero Swamp and immediate surrounding areas as early as next week. This proactive measure is done in an attempt to interrupt the virus cycle in the mosquito population. Reducing the number of mosquitoes (although it is temporary) can reduce the number of mosquitoes available to transmit virus to humans. The timing of the spraying will be determined by weather conditions and other factors, and the actual date will be announced to the public through the news media and other communication channels."

Oswego County Director of Public Health Jiancheng Huang said,"People in Oswego County should continue to use insect repellents when participating in outdoor activities and take measures to reduce mosquito breeding sites around the home."

Components of the state health department's 2018 mosquito plan include:

Mosquito Education and Outreach

At the Governor's direction, the Department of Health has issued a seasonal mosquito-borne disease health advisory to all local health departments and health care providers, on symptoms and diagnostic procedures for West Nile virus, Eastern Equine Encephalitis virus and Zika virus.This information will also be available on the Department's website and social media platforms to provide further public education emphasizing personal protection. For further information throughout mosquito season, a weekly mosquito-borne disease activity report published by the Department can be found here.

In order to protect pets and animals that may also contract or carry these diseases, DOH also provides information to veterinary medical practitioners on the appropriate procedures for diagnosing mosquito-borne illness.

In addition, the Department provides educational materials about mosquito-borne diseases at The Great New York State Fair.This year, the Department will also provide mosquito repellent wipes and larvicide at The Fair, which runs from August 22 - September 3.

Mosquito Surveillance and Assistance

  • Mosquito surveillance:Working with various county health departments, starting in early summer, the Department coordinates the weekly collection and identification of mosquitoes from traps located in key habitats for mosquitoes.Staff use the data to identify areas of disease risk and track trends in infections by geographic area and guide local decision-making and technical assistance regarding local mosquito control measures.
  • Human surveillance:Each summer, the Department sends alerts to increase healthcare providers' awareness of the symptoms of WNV, EEE and Zika. When providers suspect a mosquito-borne illness, the Department in cooperation with county health departments investigates and samples can be tested at the DOH Wadsworth Laboratory.
  • Animal surveillance:The Department and counties maintain veterinary surveillance for encephalitis in horses. Horses are very sensitive to EEE and infection is often fatal.Suspect cases are tested at the Department's Wadsworth Laboratory to confirm infection. Vaccines are available to help protect horses from EEE and WNV. Horse owners should also minimize exposure to infected mosquitoes by frequently changing water in troughs and buckets and eliminating other standing water sources.

Mosquito Prevention Tips

The Department recommends the following precautions to reduce risk of infection from mosquito-borne diseases:

  • Cover your skin as completely as possible while outside when mosquitoes are present and active. Wear long sleeves, pants and socks.
  • Use insect repellent recommended for use on exposed skin.
  • Always follow label directions before using any kind of repellent.
  • Reduce or eliminate all standing water in yards.
  • Remove discarded tires and turn over containers in which water can collect.
  • Make sure all windows and doors have screens and are free of rips, tears or holes.
  • Clean and chlorinate swimming pools, outdoor saunas and hot tubs.
  • Drain water from pool covers.
  • Clean vegetation and debris from the edges of ponds.
  • Larvicide can be used according to label directions on areas where water collects and cannot be removed or drained - see guidance here.

For more information on eastern equine encephalitis virus visit: https://www.health.ny.gov/diseases/communicable/eastern_equine_encephalitis/fact_sheet.htm