BEVERLY — A batch of mosquitoes collected in Beverly last week has tested positive for West Nile virus.
The discovery, announced Friday by the Massachusetts Department of Public Health, emphasized that no human or animal cases of the virus have been identified this year in Beverly, or elsewhere on the North Shore.
But while neither state nor local health officials indicated where in Beverly the disease-carrying sampling of mosquitoes was found, the report brings West Nile the closest yet this season to Cape Ann. The Beverly Farms area borders on the town of Manchester — the only one of Cape Ann’s four communities that has signed on this year to participate in the Northeast Massachusetts Mosquito Control District.
Beverly health officials said they will “consider” targeted spraying for mosquitoes.
“The city of Beverly has worked closely with the Massachusetts Department of Public Health and the Northeast Massachusetts Mosquito Control District throughout this season to reduce the risk of illness spread by mosquitoes,” William Burke, Beverly’s public health director, wrote in a prepared statement. “Mosquito pools are tested twice weekly from May to September in order to help identify infected mosquitoes. In addition, larvicide treatment of catch basins (where certain mosquitoes lay their eggs) was performed throughout the city.”
Spread through mosquitoes, West Nile virus can cause illness ranging from a mild fever to more serious disease such as encephalitis or meningitis, according to the Massachusetts Department of Public Health.
While the majority of people infected with West Nile exhibit no symptoms, a small percentage exhibit flu-like symptoms and less than 1 percent of people infected with West Nile develop severe illness. The elderly are more at risk of developing severe illness, health officials say.
The confirmation means that Beverly is among six Essex county towns where health officials have collected West Nile-positive mosquitoes over the past month; the others are Amesbury, Lynn, Merrimac, Newbury and Rowley.
Health officials around the region — including Rockport Health Agent Leslie Whelan and Gloucester Health Agent Noreen Burke — have urged residents to step up their protection against mosquitoes and, by extension, West Nile Virus and the potentially far more dangerous Eastern equine encephalitis.
Their tips, outlined last week in a joint letter to the Times, urged residents to avoid going outside at dusk and dawn — peak biting times for mosquitoes — to wear long-sleeved clothing and pants, and to apply insect repellent when outdoors
Residents and business owners are also advised to clear any standing puddles or pools of water, which can become especially prime breeding places for mosquitoes.
Neither Rockport nor Gloucester, however, are part of the Northeast network, and therefore do not participate in the regional body’s mosquito testing for West Nile or EEE.
Eastern equine encephalitis carried by mosquitoes was blamed in two area deaths last year; an Amesbury woman who contracted EEE and died last Sept. 24; a Georgetown man with the virus died Sept. 27.