By: Laura Soukkavong
Massachusetts has reported its 13th human case of West Nile virus this year, and the mosquito threat will persist until the first hard frost, according to the Department of Public Health. The latest case involves a woman in her 40s who was likely exposed in Middlesex County.
Eleven communities remain at high risk: Boston, Brookline, Cambridge, Chelsea, Everett, Malden, Newton, Revere, Somerville, Watertown and Winthrop. Most of the rest of Massachusetts is at moderate risk. DPH is urging residents to protect themselves from mosquito bites and check local risk levels regularly.
Since announcing the season’s first West Nile-positive mosquitoes on June 16, DPH has recorded 344 positive mosquito samples. Those samples came from Barnstable, Berkshire, Bristol, Dukes, Essex, Franklin, Hampden, Hampshire, Middlesex, Norfolk, Plymouth, Suffolk and Worcester counties. No animal cases of West Nile virus have been reported this year.
Eastern equine encephalitis is also being detected in Massachusetts mosquitoes. DPH reported 27 EEE-positive mosquito samples this year, with no human or animal EEE cases reported so far. The mosquito findings underscore the need for continued precautions even as the season advances.
DPH advises using insect repellent according to its label and wearing long sleeves, long pants and socks outdoors. Many mosquitoes are most active from dusk to dawn, and residents in high-risk areas should consider moving evening or early-morning outdoor activities to another time.
Families should follow age restrictions on repellents. DPH says DEET products should not be used on infants younger than two months, and concentrations should be 30 percent or less for older children. Oil of lemon eucalyptus should not be used on children younger than three.
At home, residents should drain or discard items holding standing water, check gutters and drains, empty unused flowerpots and wading pools, and frequently change birdbath water. Tight-fitting window and door screens should be installed or repaired to keep mosquitoes outside.
Animal owners should also remove standing water and flush water troughs at least weekly during summer. DPH recommends keeping horses in indoor stalls at night and consulting a veterinarian about animal-approved repellents and vaccinations against West Nile virus and EEE.
Suspected animal cases must be reported to the Department of Agricultural Resources’ Division of Animal Health at 617-626-1795 and DPH at 617-983-6800. DPH updates its Massachusetts Arbovirus Update and Arbovirus Surveillance Information web pages daily. Residents can also call the DPH Division of Epidemiology at 617-983-6800 for more information.