- Department of Public Health
Media Contact for State public health officials announce eighth human case of West Nile virus in Massachusetts
Katheleen Conti, Assistant Director of Media Relations
Boston — The Massachusetts Department of Public Health (DPH) today announced an additional human case of West Nile virus (WNV) in the state, bringing the total number of WNV cases this year to eight. The individual is a male in his 40s, who was exposed to WNV in Middlesex County.
Most WNV virus activity this year has continued to be focused in an area around Boston and includes parts of Norfolk, Middlesex, and Essex counties. Information about current mosquito activity will continue to be updated regularly and can be found here. In 2019, there were five human cases of WNV infection.
WNV is usually transmitted to humans through the bite of an infected mosquito. While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe disease.
When present, WNV symptoms tend to include fever and flu-like illness. In rare cases, more severe illness can occur. However, most people infected with WNV will have no symptoms.
People have an important role to play in protecting themselves and their loved ones from illnesses caused by mosquitoes. DPH recommends the following precautions:
Avoid Mosquito Bites
Apply Insect Repellent when Outdoors. Use a repellent with DEET (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), 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% 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 the evening or early morning.
Clothing Can Help Reduce Mosquito Bites. Wear long-sleeves, long pants, and socks when outdoors to 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 either draining or discarding items that hold water. Check rain gutters and drains. Empty any 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 of your 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 at least once a week during the summer months 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 WNV and Eastern Equine Encephalitis (EEE). If an animal is diagnosed with 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 DPH by calling 617-983-6800.
More information, including all WNV and EEE positive results, can be found on the Arbovirus Surveillance Information web page or by calling the DPH Epidemiology Program at 617-983-6800.