Press Releases

09/04/2019

Risk of Mosquito-Borne Diseases Continues: Eastern Equine Encephalitis Positive Mosquitoes Found in 10 Connecticut Towns

West Nile Virus Detected in 17 Connecticut Towns

New Haven, CT – The State Mosquito Management Program is warning Connecticut residents about the risk of infection by eastern equine encephalitis (EEE) and West Nile virus (WNV) this season.  So far, the Connecticut Agricultural Experiment Station (CAES) has detected EEE-infected mosquitoes in: Chester, Haddam, Hampton, Killingworth, Madison, North Stonington, Plainfield, Shelton, Stonington, and Voluntown.  In addition, WNV-infected mosquitoes have been detected in: Bridgeport, Chester, East Haven, Greenwich, Groton, Hartford, Manchester, New Haven, North Haven, North Stonington, Norwalk, South Windsor, Stamford, Voluntown, West Hartford, West Haven, and Wethersfield.

"We continue to see exceptionally high numbers of mosquitoes carrying EEE virus especially in communities in southeastern Connecticut,” said Dr. Philip Armstrong, Medical Entomologist at the CAES. “In addition, we are detecting WNV in numerous towns throughout the state. Late summer-early fall is the critical time of the year when virus activity reaches its peak in the mosquito population."

“We are experiencing an extremely active season for EEE throughout much of the northeastern US, with multiple human and horse cases now being reported in Massachusetts, New York, New Jersey and Rhode Island.  We strongly encourage residents throughout the state to take simple steps to prevent mosquito bites,” said Dr. Theodore Andreadis, Director of the Center for Vector Biology & Zoonotic Diseases at the CAES.  "This includes applying insect repellent and covering bare skin, especially during dusk and dawn when biting mosquitoes are most active.”

2019 Eastern Equine Encephalitis Activity

 

2019 West Nile Virus Activity

There are no reported human cases of EEE or WNV infection so far this year in Connecticut.  Two horse cases of EEE (Colchester and Columbia) and one horse cases of WNV infection (Easton) have been reported in Connecticut this year.

Eastern equine encephalitis is a rare but serious mosquito-borne viral disease in people and horses. On average, there are 6 human cases reported each year in the United States. The mortality rate of hospitalized patients is one-third and approximately one-half of survivors suffer from permanent neurological damage. In Connecticut, outbreaks of EEE have occurred sporadically in horses since 1938 and the first locally-acquired human case and fatality occurred in the fall of 2013.

West Nile virus is the most common mosquito-borne viral disease in the United States and reemerges every summer in Connecticut. One hundred fifty-seven human cases of West Nile virus, including 4 deaths, have been diagnosed in Connecticut residents since 2000.

To reduce the risk of being bitten by mosquitoes residents should:

  • Minimize time spent outdoors between dusk and dawn when mosquitoes are most active.
  • Be sure door and window screens are tight-fitting and in good repair.
  • Wear shoes, socks, long pants, and a long-sleeved shirt when outdoors for long periods of time, or when mosquitoes are more active. Clothing should be light colored and made of tightly woven materials that keep mosquitoes away from the skin.
  • Use mosquito netting when sleeping outdoors or in an unscreened structure and to protect small babies when outdoors.
  • Consider the use of mosquito repellent, according to directions, when it is necessary to be outdoors.

The State of Connecticut Mosquito Management Program is a collaborative effort involving the Department of Energy & Environmental Protection, the Connecticut Agricultural Experiment Station, the Department of Public Health, the Department of Agriculture, and the University of Connecticut Department of Pathobiology and Veterinary Science. These agencies are responsible for monitoring the potential public health threat of mosquito-borne diseases.

The CAES maintains a network of 92 mosquito-trapping stations in 72 municipalities throughout the state. Mosquito traps are set Monday – Thursday nights at each site every ten days on a rotating basis. Mosquitoes are grouped (pooled) for testing according to species, collection site, and date.  Positive findings are reported to local health departments and on the CAES website at https://portal.ct.gov/CAES/Mosquito-Testing/Introductory/State-of-Connecticut-Mosquito-Trapping-and-Arbovirus-Testing-Program.

For information on West Nile and eastern equine encephalitis viruses and how to prevent mosquito bites, visit the Connecticut Mosquito Management Program Website at https://portal.ct.gov/mosquito.