Massachusetts health officials reported an additional nine human West Nile virus (WNV) cases Friday, bringing the total to 38 for the year. This breaks the previous record of 33 human cases reported in 2012.


“The forecast includes some warm fall temperatures,” said Public Health Commissioner Monica Bharel, MD, MPH.  “Mosquitoes might still be active and it remains important for people to use mosquito repellent and wear long sleeves to reduce exposed skin.”

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. Most people infected with WNV will have no symptoms. When present, WNV symptoms tend to include fever and flu-like illness. In rare cases, more severe illness can occur.

As of today, Massachusetts has recorded 190 human WNV cases since the first case was reported in 2001.

Nationally, 1,611 cases of West Nile virus disease in people have been reported to CDC as of Oct 2, including 68 deaths.