West Nile Virus Detected in Danbury Mosquitoes, Health Officials Urge Precautions

DANBURY, CT — Mosquitoes collected in Danbury have tested positive for West Nile virus, the Connecticut Mosquito Management Program confirmed Tuesday, marking the first detection in the city this season.

The virus was identified at a local testing site and follows prior detections in Danbury in 2007, 2020, 2023, and 2024. Statewide, West Nile virus has been present since 1999. No human infections associated with the virus have been reported in Danbury this year, and officials say the risk to the public remains low with proper precautions.

Related: Mosquitoes Test Positive For West Nile Virus In Greenwich

"Simple measures such as using insect repellent, wearing protective clothing, and eliminating standing water can significantly reduce the risk of infection," said Fernanda Carvalho, director of Danbury’s Department of Health and Human Services. The city manages more than 5,500 catch basins each summer as part of its mosquito control program.

West Nile virus is transmitted through the bite of an infected mosquito. While many people experience no symptoms, others may develop fever, headache, joint pain, vomiting, or rash. Severe cases can lead to neurological complications such as encephalitis or meningitis, particularly among individuals over 60 or with weakened immune systems.

To limit the risk of infection, public health officials recommend:

• Avoiding outdoor activity between dusk and dawn, when mosquitoes are most active.
• Using EPA-registered insect repellents containing DEET, Picaridin, IR3535, oil of lemon eucalyptus, PMD, or 2-undecanone.
• Wearing long-sleeved shirts, pants, socks, and shoes when outdoors, especially during mosquito-prone hours.
• Ensuring window and door screens are in good repair.
• Using mosquito netting in outdoor or unscreened sleeping areas.

According to state health data, 180 human cases of West Nile virus, including four fatalities, have been reported in Connecticut since 2000.

Related: Connecticut Confirms Season’s First West Nile Virus-Positive Mosquitoes

The Connecticut Mosquito Management Program will continue monitoring mosquito populations across the state. For local inquiries, contact the Danbury Health Department at 203-797-4625 or email healthdept@danbury-ct.gov.