The Massachusetts Department of Public Health (DPH) Wednesday announced the second human case of West Nile virus (WNV) in the state this year. The woman is a resident of Middlesex County in her 40’s who was hospitalized, but has been released and is recovering. Both cases this year were from Middlesex County.

West Nile virus
Culex quinquefasciatus

This finding raises the risk level to “Moderate” in the following communities: Melrose, Reading, Saugus, Stoneham, Wakefield, Winchester and Woburn.

“While cooler weather reduces mosquito activity, risk for mosquito-borne illness remains a concern until the first hard overnight frost,” said State Public Health Veterinarian Dr. Catherine Brown. “Residents need to continue to take steps to protect themselves against mosquito bites: use insect repellant, cover up, and avoid outdoor activities at dusk and after nightfall when mosquitoes are at their most active.”

This is the second human case of WNV in the state this year. In 2013, there were eight human cases of WNV infection identified in Massachusetts. While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe disease. WNV is usually transmitted to humans through the bite of an infected mosquito.  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.

Nationally as of September 9, a total of 45 states and the District of Columbia have reported West Nile virus infections in people, birds, or mosquitoes. Overall, 579 cases of West Nile virus disease in people have been reported to CDC .