State Reports Positive Mosquitoes for West Nile Virus in Milford

First WNV-Positive Mosquito Pool of Season

MEDIA CONTACT:
Dr. Philip Armstrong
The Connecticut Agricultural Experiment Station
203-974-8510; Philip.Armstrong@ct.gov

John Shepard
The Connecticut Agricultural Experiment Station
203-974-8517; John.Shepard@ct.gov

New Haven, CT – The State of Connecticut Mosquito Management Program (MMP) announced that mosquitoes trapped in Milford on June 29 tested positive for West Nile virus (WNV). These results represent the first WNV positive mosquitoes identified in the state by the Connecticut Agricultural Experiment Station (CAES) this year. Connecticut residents are reminded to protect themselves from mosquito bites and mosquito-borne diseases.

“The first West Nile virus positive mosquitoes of the season have been identified,” said John Shepard, Medical Entomologist at the CAES. “The recent rainfall, high humidity, and warm temperatures are expected to increase mosquito activity and virus build-up in the weeks ahead. We will continue to closely monitor mosquitoes for virus infection from now through October.”

"This serves as an important reminder for people to protect themselves from mosquito bites," said Dr. Philip Armstrong, Chief Scientist at the CAES. " We encourage everyone to take simple precautions, such as wearing mosquito repellent and covering bare skin, especially during dusk and dawn when mosquitoes are most active."

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

Minimize time spent outdoors between dusk and dawn when mosquitoes are most active.
When it is necessary to be outdoors, use mosquito repellents containing an EPA-registered active ingredient, including DEET, Picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol (PMD), or 2-undecanone. EPA registration of skin-applied repellent products indicates that they have been evaluated and approved for human safety and effectiveness when applied according to instructions on the label.
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 loose-fitting and made of tightly woven materials that keep mosquitoes away from the skin.
Wear clothing and gear treated with permethrin. Permethrin is an insecticide that kills or repels mosquitoes and ticks.
Be sure door and window screens are tight-fitting and in good repair.
When sleeping outdoors, use tents or mosquito netting in an unscreened structure. Treat camping gear with permethrin when possible.
Cover strollers and baby carriers with mosquito nets when outside.

Last year, WNV was detected in 230 mosquito samples from 37 towns in 6 counties in Connecticut. The majority of WNV activity occurred in urban and suburban regions in Fairfield, Hartford, and New Haven counties. The virus is detected in the Northeast every summer and has become the leading cause of mosquito-borne disease in the region.

In 2025, six Connecticut residents were hospitalized with WNV disease; one death was reported among these. Most human infections are acquired from mosquito bites occurring during July through September. The majority of people infected with WNV do not develop symptoms. Approximately 80% of infected individuals remain asymptomatic, while about 20% develop a mild illness characterized by symptoms such as fever, headache, body aches, joint pain, vomiting, diarrhea, or rash. Fewer than 1% of infected individuals develop severe neuroinvasive disease, which can affect the brain, spinal cord, or surrounding tissues and may result in hospitalization, long-term neurological complications, or death.

Connecticut Mosquito Management Program

The response to mosquito transmitted diseases in Connecticut is a collaborative inter-agency effort involving the Department of Energy and Environmental Protection (DEEP), the Connecticut Agricultural Experiment Station (CAES), the Connecticut Department of Public Health (DPH), the Department of Agriculture, and the Connecticut Veterinary Medical Diagnostic Laboratory (CVMDL) at the University of Connecticut (UCONN). These agencies are responsible for monitoring mosquito populations and the potential public health threat of mosquito-borne diseases.

CAES maintains a network of 108 mosquito-trapping stations in 88 municipalities throughout the state. Mosquito traps are set Monday – Thursday nights at each site every 10 days on a rotating basis and then at least once a week after detection of virus. 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.

For information on WNV and Eastern equine encephalitis (EEE), what can be done to prevent being bitten by mosquitoes, the latest mosquito test results, and human infections, visit the Connecticut Mosquito Management Program website.