MERRIMAC — Town health officials ask residents to take precautions after the discovery of mosquitoes infected with West Nile virus in nearby Haverhill.
The insects were among those trapped at a specific mosquito surveillance site, Merrimac Health Agent Deborah Ketchen and the town’s Board of Health announced in a news release Thursday night.
The state Department of Public Health later confirmed that the mosquitoes tested positive for the potentially deadly virus, the health officials said.
The Health Board urged local residents to take proper precautions and offered tips, noting that the town’s risk level for West Nile virus remained the same.
It was not noted whether these mosquitoes were among those that tested positive for West Nile virus and Eastern equine encephalitis in Haverhill on July 30.
Last week, Newburyport confirmed a case of West Nile virus in the city and urged its residents to take precautions. None of the cases in either community involve infected humans.
Haverhill Mayor Melinda Barrett announced on the city’s website Aug. 2 that spraying for mosquitoes would begin three days later in a northeastern section of the community due to the positive findings.
Trucks from the Northeast Massachusetts Mosquito Control District were to begin spraying the insecticide Zenivex E4 RTU in an area “bounded by Main Street to Kenzoa Avenue to Amesbury Road to Kenzoa Street to Center Street to Millvale Road to East Broadway to Old Ferry Road to Lincoln Avenue to Water Street then back to Main Street,” the city said.
Public health surveillance is conduced in the state for both mosquito-borne illnesses. The highest risk for contracting WNV or EEE is from late July to the first fall frost, according to Merrimac officials.
Mosquitoes receive WNV and EEE by biting infected birds. People and animals contract these diseases by being bitten by an infected mosquito.
Most people bitten by mosquitoes carrying WNV will either have no symptoms or very mild symptoms and recover on their own. People over age 50 have the highest risk of becoming seriously ill, the Merrimac officials said. Additional monitoring and testing of mosquitoes in Haverhill was expected.
Merrimac health officials and Barrett encourage the public to take precautions, including using DEET mosquito repellant, wearing long sleeves and pants, and avoiding outdoor activities from dusk to dawn.
Residents are also asked to check their property for containers of standing water that could attract mosquitoes. Tightly fitted screens are needed for windows and doors, the officials said.
More information about WNV and EEE is available by calling the state Department of Public Health recorded information line at 1-866-MASS-WNV (1-866-627-7968), or the DPH Epidemiology Program at 617-983-6800.
A fact sheet is available at mass.gov/doc/wnv-factsheet-english/download.