West Nile virus spreading in mosquitoes across the state

Mosquitoes are flourishing in this year's rainy season, spreading West Nile virus across Massachusetts, state health experts said this afternoon.

West Nile virus-infected mosquitoes have been trapped in Merrimac, Abington, Worcester, Springfield, Chicopee, Fall River, Somerset, and Dedham, according to the state Department of Public Health. A blue jay in Boston has tested positive for the virus, the second bird with the illness in the city among 10 across the state this summer. No human cases have been reported.

"People should consider the virus as being established in these areas for the summer," state epidemiologist Dr. Al DeMaria said in a statement. "We are continuing to find virus in new areas; the warm, wet summer is continuing to support mosquito populations and allowing the virus to spread.”

West Nile virus is transmitted to humans through the bite of an infected mosquito. Six people contracted the illness last year in Massachusetts. Most people aren't aware they are infected, but in one of five who are, it can lead to flu-like symptoms. In an even smaller number, about 1 in 150 infected people, the illness is a more serious infection of the brain or spinal cord.

To avoid mosquito bites, health experts recommend staying inside from dusk to dawn or using clothing or insect repellent to cover bare skin when outdoors. Drain standing water outside your home to discourage mosquito breeding and keep mosquitoes outside with tight screens.