Press Release  State health officials announce 11th human case of West Nile virus and EEE risk level change

Boston — The Massachusetts Department of Public Health (DPH) today announced the 11^th human case of West Nile virus (WNV) in the state this year. The person is a man in his 60s with recent out-of-state travel.

Although the person’s recent travel outside of Massachusetts means the exact location of exposure is uncertain, there is a possibility he could have been exposed within the Greater Boston area, which is already known to be at high risk for WNV.

Additionally, DPH announced today it is raising the Eastern equine encephalitis (EEE) risk levels to high in Concord in Middlesex County due to two consecutive weeks of EEE-positive mosquito findings in species known to be able to spread the virus to humans. This is an expansion of an area already considered to be at high risk from EEE.

"It may be mid-September, but warm and humid weather continues across Massachusetts, keeping the risk of both EEE and West Nile elevated," said Public Health Commissioner Robbie Goldstein, MD, PhD. "There will continue to be risk from mosquito-borne disease until the first hard frost, and I encourage everyone to continue to take measures to protect themselves by using mosquito repellent with an EPA-registered active ingredient when outdoors, wearing long sleeves and pants, and being aware of peak mosquito hours."

There have been 314 WNV-positive mosquito samples so far this year detected from Barnstable, Berkshire, Bristol, Dukes, Essex, Franklin, Hampden, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester counties. There have been 95 EEE-positive mosquito samples, four human cases, and two horse cases reported in Massachusetts so far this year.

People have an important role to play in protecting themselves and their loved ones from illnesses caused by mosquitoes.

Avoid Mosquito Bites

Apply Insect Repellent when Outdoors. Use a repellent with an EPA-registered ingredient, such as DEET (N,N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), or oil of lemon eucalyptus (p-menthane-3,8-diol (PMD) or IR3535) according to the instructions on the product label. DEET products should not be used on infants under two months of age and should be used in concentrations of 30 percent or less on older children. Oil of lemon eucalyptus should not be used on children under three years of age.

Be Aware of Peak Mosquito Hours. The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning in areas of high risk.

Clothing Can Help Reduce Mosquito Bites. Wearing long sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.

Mosquito-Proof Your Home

Drain Standing Water. Mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by draining or discarding items that hold water. Check rain gutters and drains. Empty unused flowerpots and wading pools and change the water in birdbaths frequently.

Install or Repair Screens. Keep mosquitoes outside by having tightly fitting screens on all windows and doors.

Protect Your Animals

Animal owners should reduce potential mosquito breeding sites on their property by eliminating standing water from containers such as buckets, tires, and wading pools – especially after heavy rains. Water troughs provide excellent mosquito breeding habitats and should be flushed out to reduce mosquitoes near paddock areas. Horse owners should keep horses in indoor stalls at night to reduce their risk of exposure to mosquitoes. Owners should also speak with their veterinarian about mosquito repellents approved for use in animals and vaccinations to prevent West Nile virus (WNV) and EEE. If an animal is suspected of having WNV or EEE, owners are required to report to the Department of Agricultural Resources, Division of Animal Health by calling 617-626-1795, and to the Department of Public Health by calling 617-983-6800.

More information, including all WNV and EEE positive results, can be found on the Arbovirus Surveillance Information web page at Mosquito-borne Diseases | Mass.gov, which is updated daily, or by calling the DPH Division of Epidemiology at 617-983-6800. 

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