The Connecticut Department of Public health says mosquito samples in Greenwich, Stamford, Darien and Bridgeport have recently tested positive for the West Nile Virus.
Officials say there are no reported human cases of West Nile this season.
A state program tests mosquitoes across the state every ten days.
Experts are tracking West Nile virus, Eastern Equine Encephalitis, Zika and the emerging Jamestown Canyon virus.
Officials say reducing your time outdoors at dusk and dawn can reduce the potential for mosquito bites.
