Massachusetts Reports 12th West Nile Virus Case as Norfolk County Exposure Lifts Risk Levels in Milton and Quincy
A woman in her 60s who was likely exposed in Norfolk County represents the 12th human case of West Nile virus identified in Massachusetts this year, according to the Massachusetts Department of Public Health. Health officials elevated the virus risk level to high in Milton and Quincy following the exposure.
Elevated Risk Areas Across Massachusetts
Risk levels for West Nile virus remain high in Boston, Brookline, Cambridge, Chelsea, Everett, Malden, Newton, Revere, Somerville, Watertown, and Winthrop. Most remaining parts of the state currently sit at moderate risk. The threat from the virus will persist until the first hard frost of the season occurs.
The state identified its first positive mosquito sample of the year on June 16. Since then, testing has confirmed 340 mosquito samples positive for the virus across Barnstable, Berkshire, Bristol, Dukes, Essex, Franklin, Hampden, Hampshire, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester counties. Zero animal cases have emerged this season.
Eastern Equine Encephalitis Surveillance
Eastern equine encephalitis continues to circulate among mosquito populations in Massachusetts. Testing detected 27 positive mosquito samples this year, while human and animal cases remain at zero. Daily updates on surveillance and community risk levels are published online through the Massachusetts Arbovirus Update web page by the Department of Public Health.
Personal Protection and Mosquito Prevention
Residents can reduce their risk of mosquito-borne illness by applying insect repellent containing EPA-registered ingredients such as DEET, permethrin, picaridin, or oil of lemon eucalyptus according to product labels. The Department of Public Health advises avoiding outdoor activities during peak biting hours from dusk to dawn and wearing long sleeves, long pants, and socks outside.
Homeowners should eliminate standing water around properties by draining unused flowerpots, wading pools, and clearing rain gutters. Installing tight-fitting window and screen doors also keeps mosquitoes out of living spaces. Animal owners need to flush out water troughs weekly and keep horses in indoor stalls at night to minimize exposure.
What Restrictions Apply to Insect Repellents for Children?
What restrictions apply to insect repellents for children?
DEET products must not be used on infants under two months of age and should be applied in concentrations of 30 percent or less on older children. Oil of lemon eucalyptus is prohibited for use on children under three years of age.
What steps should horse owners take to protect their animals?
Horse owners should stable horses indoors at night to reduce mosquito exposure. Owners must also consult veterinarians regarding approved animal repellents and vaccinations for West Nile virus and Eastern equine encephalitis.
Where should suspected animal cases of West Nile virus be reported?
Suspected animal cases require mandatory reporting to the Department of Agricultural Resources Division of Animal Health at 617-626-1795 and the Department of Public Health at 617-983-6800.
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