The risk of contracting a vector borne infection such as West Nile Virus increases during the summer months as mosquitoes become active. Taking a few simple precautions can greatly reduce the risk of infection and keep you healthy this summer season.

West Nile Virus (WNV) and Eastern Equine Encephalitis (EEE)

Both West Nile Virus and EEE are spread to humans through the bite of an infected mosquito. The mosquitoes that transmit EEE are most frequently found near freshwater, hardwood swamps.

Approximately 80% of those infected with West Nile Virus will show no symptoms and when symptoms do appear they are generally mild, resolve on their own, and do not require hospitalization. A small percentage of individuals (1%) infected with WNV will develop severe disease, almost always requiring hospitalization. Approximately 10% of individuals displaying severe disease will die from WNV. Symptoms of WNV include:  headache, fever, nausea, body aches, swollen lymph glands, skin rash, and vomiting.  Severe disease can lead to encephalitis or meningitis.

EEE is a very rare disease, with fewer than 100 cases in Massachusetts since 1938. There is no treatment for EEE; approximately 50% of those infected will die from the disease. The symptoms of EEE include: high fever (103°-106°F), stiff neck, headache, and fatigue. Symptoms generally appear 3-10 days after the bite of an infected mosquito. Encephalitis is the most serious complication of EEE.

To protect yourself from WNV and EEE: mosquito

  • Use insect repellant containing DEET, picaridin, IR3535, or some oil of lemon eucalyptus, as directed on bottle
  • Eliminate sources of standing water such as buckets, flower pots, and wheelbarrows where mosquitoes breed
  • Avoid outdoor activity at dusk when mosquitoes are most active
  • Secure all windows and doors; patch window screens
  • Wear long sleeves and pants while outside