Eastern Equine Encephalitis (EEE)

On September 30, 2019, Quinnipiack Valley Health District (QVHD) received a report that the Bethany trapping station had a Cs. melanura mosquito pool collected on September 23, 2019 test positive for eastern equine encephalitis virus (EEEV). According to the CDC, “Cs. melanura is not considered to be an important vector of EEEV to humans because it feeds almost exclusively on birds.” 

QVHD advises residents of QVHD to protect themselves and their children by taking personal protective measures to prevent mosquito bites and minimizing outdoor activity from dusk to dawn, when mosquitoes are most active.

QVHD recommends the following precautionary measures:

  • The suspension of school and town sponsored activities from dusk to dawn, when mosquitos are most active.
  • If outdoor activity is unavoidable, especially around dawn or dusk, be sure to use insect repellent and cover bare skin.
  • Use insect repellent, according to label instructions, when it is necessary to be outdoors.
  • 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. Clothing should be light-colored and made of tightly woven materials that keep mosquitoes away from the skin.
  • Eliminate mosquito breeding sites by emptying standing water from buckets, barrels and other containers.
  • Consider mosquito-netting for carriages, strollers and tents.

 NOTE: These measures also help to protect against infection with West Nile virus, another virus transmitted by mosquitoes.

The Department of Public Health (DPH) continues to advise against unnecessary trips into mosquito breeding grounds such as marshes as the mosquitoes that transmit EEE virus are associated with freshwater swamps. Overnight camping or other substantial outdoor exposure in freshwater swamps in Connecticut should be avoided. 

Visit the EPA website to learn more about which safe and effective repellent is right for you and your family:             

                                                                                                      Eastern Equine Encephalitis (EEE)

                                                                                                           Frequently Asked Questions


What is eastern equine encephalitis?
Eastern equine encephalitis (EEE) is a rare but serious disease caused by a virus.

Where is the virus found?

This virus grows in birds that live in fresh water swamps and is generally found only in these birds and in mosquitoes that usually do not bite people. Sometimes the virus gets picked up by other types of mosquitoes that bite other birds, animals, and people.

How is this virus spread?

It is spread by the bite of an infected adult mosquito. The virus is not spread directly from person-to-person.

Who gets EEE?
Anyone can get EEE if bitten by an infected mosquito but most mosquitoes in Connecticut do not carry EEE. The greatest risk for being bitten by an infected mosquito is from late July to mid-October during activities near fresh water swamps.

What are the symptoms of EEE?
Early symptoms include high fever (103° - 106°F), stiff neck, severe headache, and lack of energy. The disease worsens quickly and some patients go into a coma within a week. Encephalitis (swelling of the brain) is the most dangerous symptom.

How soon do symptoms appear?
Symptoms can appear anywhere from 3 to 10 days after being bitten by an infected mosquito.

What is the treatment for EEE?
There is no cure for EEE. Three of every ten people who get the disease will die from it.

How can EEE be prevented?

The only way to protect yourself is to keep mosquitoes from biting you. 

  • If you are outdoors at dawn or dusk when mosquitoes are most active, wear long-sleeved shirts and long pants.
  • Consider using insect repellent, according to manufacturer's instructions.
  • Fix any holes in your screens and make sure they are tightly attached to all doors and windows.
  • Do not let stagnant water collect around your home. Mosquitoes can breed in water that collects in ditches, clogged gutters, old tires, wheelbarrows, or wading pools.
  • Do not camp overnight near freshwater swamps. 
  • Consider mosquito-netting for carriages, strollers and tents.

QVHD is in frequent, communication with state partners and local partners on precautionary measures to take regarding EEE and any new information pertaining to EEE in our district towns (Bethany, Hamden, North Haven, Woodbridge). The Health District will continue to monitor mosquito activity and update messages until the first hard frost.

How can I get more information on EEE?

Bethany, Hamden, North Haven & Woodbridge residents:

Contact QVHD, 203-248-4528

For specific questions on human infections, contact the Connecticut Department of Public Health at 860-509-7994.



Connecticut Department of Public Health

State of Connecticut Mosquito Management Program


Announcement Date: 
Tuesday, October 1, 2019