The single mosquito pool that tested positive for West Nile virus in Harvard contained Coquillettidia perturbans, a mosquito species that breeds in swamp-like habitats on the stalks of cattails or marshy grasses. Although this is one of the most prevalent species in the state, Harvard’s positive West Nile test result on this species is the only one in the state so far this year. The test was conducted Aug. 27, and the Harvard Board of Health was notified by the Massachusetts Department of Public Health (MDPH) of the positive result.
Dr. Catherine Brown, MDPH veterinarian, said that Harvard’s traps were collected in the southwest quadrant of the town. She added that the state does not release exact addresses because it doesn’t want people to focus on one location. “If there is one positive test, it’s in the area,” said Dr. Brown.
Board of Health response
News of the positive test result initially sparked some concern among residents, as evidenced by posts on Nextdoor Harvard and phone calls to the health board. At the board’s Sept. 9 meeting, board Chairman Tom Philippou said, “The board feels that we’ve done an adequate job of informing the public of this ever-present concern. A single positive result attests to the concern.”
Mosquito testing
The MDPH conducts random mosquito tests in towns such as Harvard that are not members of any of the 11 mosquito control projects in the state. Mosquitoes are trapped and sorted by species into groups of 10 to 50 called “pools.” The MDPH reported that this summer, as of Sept. 9, of the 3,743 pools tested, 116 tested positive for West Nile virus.
Risk is still low but present
The MDPH identifies Harvard’s West Nile risk as low, meaning that infection is unlikely. But in this week’s MDPH report on mosquito-borne illnesses, the department advises that the current weather patterns in the state continue to support the mosquito species that spread West Nile. The report also stated that September is when people are most likely to be exposed to infected mosquitoes. For more information on mosquito-borne diseases and how to protect yourself, go to the Harvard Board of Health website at http://harvard.ma.us/Pages/HarvardMA_BComm/BOH/index or the MDPH website at www.mass.gov/dph/mosquito.
