Mosquitoes Test Positive For West Nile Virus In Cheshire: Health Department

CHESHIRE, CT — The Connecticut Agricultural Experiment Station (CAES) identified West Nile Virus-infected mosquitoes in Cheshire, according to a news release from the Chesprocott Health District.

Hilary Norcia, the acting director of the Chesprocott Health District, said Monday that a mosquito collected at Lock 12 in Cheshire has tested positive for West Nile virus (WNV). This is the first detection of WNV in Cheshire for the2025 season.

“West Nile virus is a recurring seasonal concern in our region,” Norcia said. “While no human cases have been reported, we urge residents to take simple but effective steps to protect themselves from mosquito bites.”

Cheshire is the latest of several Connecticut towns to find itself an infected mosquito haven. The first mosquitoes to test positive for WNV in Connecticut this season were detected in Bridgeport, collected on June 11 as part of the state’s routine surveillance program.

See Also: Mosquitoes Test Positive For West Nile Virus In Greenwich: Health Department

A mosquito becomes infected when it bites a bird carrying the virus. WNV is not spread by person-to-person contact or directly from birds to people.

General symptoms occur suddenly between five and 15 days following the bite of an infected mosquito and range from slight fever, headache, rash, swollen lymph nodes, nausea, malaise and eye pain, to the rapid onset of severe headache, high fever, stiff neck, disorientation, severe muscle weakness, gastrointestinal symptoms, coma or death, the Greenwich Department of Health said.
Most people who are bitten by an infected mosquito are able to fight off infection and experience mild or no symptoms at all.

Some individuals, including the elderly and persons with compromised immune systems, can experience serious illness that affects the central nervous system.

In a minority of infected persons, especially those over 50 years old, WNV can cause serious illness, including encephalitis and meningitis, according to the Greenwich Department of Health.
Infection can lead to death in three to 15 percent of persons with severe forms of the illness.

To reduce the risk of mosquito bites, residents are advised to:

• Use EPA-registered mosquito repellents
• Wear light-colored, loose-fitting clothing
• Ensure window and door screens are in good condition
• Use mosquito netting when sleeping outdoors or protecting children in strollers

The CAES operates 108 trapping stations in 88 municipalities across the state. Traps are rotated weekly, with increased frequency following any detection of viruses. Test results and public health alerts are shared with local health departments and posted online here.

The mosquito surveillance and response effort is a collaboration between CAES, the Department of Public Health, the Department of Energy and Environmental Protection, the Department of Agriculture, and the Connecticut Veterinary Medical Diagnostic Laboratory at UConn.