STAMFORD - State health officials say a mosquito trapped in Stamford last week has tested positive for the West Nile virus.

Experts say the unseasonably warm weather earlier this year may be responsible for an early start to the season and could lead to a spike in cases.

The state Department of Health urges residents to stay covered when possible and to wear bug repellent to decrease their risk.

Health officials say they will now test mosquitoes in designated sites two to three times per week instead of just once. Researchers say the virus usually first appears mid-July to August.