State Health Officials Announce First Human Case of West Nile Virus in Massachusetts

BOSTON — On Thursday, the Massachusetts Department of Public Health (DPH) announced the first human case of West Nile virus (WNV) in the state this year. The individual is a female in her 70s who was exposed to the virus in Suffolk County.

“This is the first time that West Nile virus infection has been identified in a person in Massachusetts this year,” Public Health Commissioner Margret Cooke said. “August and September are the months when most cases of West Nile virus occur. Although the significant drought conditions that exist across the Commonwealth have kept the populations of the Culex mosquito species that are most likely to spread WNV relatively small, today’s news is an important reminder that we all need to take steps to protect ourselves and our families from mosquito bites.”

In 2021, there were 11 human cases of WNV infection identified in Massachusetts. WNV is usually transmitted to humans through the bite of an infected mosquito. While it 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.

No human or animal cases of Eastern equine encephalitis (EEE) have been detected so far this year.