Health & Environment Police & Fire

Boston Mosquito Pools Test Positive for West Nile Virus

Announcement from Boston Public Health Commission:

Mosquito pools in Back Bay/Fens and South Dorchester have tested positive for West Nile Virus (WNV), the Boston Public Health Commission reported today. In July, positive samples were found in mosquito pools in East Boston, North Dorchester, Hyde Park, Jamaica Plain, and West Roxbury. In June, a positive mosquito pool was found in Roslindale. There have still been no confirmed human cases of WNV in Boston this year.

“As we have seen so far this summer, mosquitoes infected with West Nile Virus can be found anywhere in Boston. It’s very important than people take some simple precautions to avoid mosquito bites,” said Dr. Anita Barry, director the Infectious Disease Bureau at the Public Health Commission.

These steps include using insect repellant when outdoors, especially from dusk to dawn when mosquitoes are more likely to be biting and, when possible, wearing clothing that includes long sleeves and pants.  People can avoid attracting mosquitoes in their homes by making sure that their window and door screens are in good repair to prevent mosquitoes from getting into the house.

To prevent mosquitoes from breeding, BPHC advises limiting places around the home where standing water can collect. People should turn over unused flower pots, buckets, wheelbarrows, and garbage cans; remove leaves and other debris that can clog gutters and trap water; dispose of or cover old tires; and cover swimming pools and kiddie pools when not in use.

While WNV is most commonly transmitted to humans by the bite of a mosquito infected with the virus, it poses very low risk to humans. The risk can be further reduced by following the precautionary measures above. In addition, the city has been applying larvicide in catch basins throughout Boston to reduce the adult mosquito population.

Please see the fact sheet (pdf) to help protect yourself and family from WNV.

For more information on WNV, call the Boston Public Health Commission at 617-534-5611 or visit