State officials have confirmed a second case of West Nile virus this year.
The victim, a woman in her 40s who lives in Middlesex County, was hospitalized by the disease, but has been released and is recovering, according to the state's Executive Office of Health and Human Services.
State officials have not identified the woman nor her hometown. The finding raises the West Nile virus risk level to "moderate" in Melrose, Reading, Saugus, Stoneham, Wakefield, Winchester and Woburn.
In 2013, according to state health officials, there were eight human cases of WNV infection identified in Massachusetts. People over the age of 50 are at higher risk for severe disease, according to the state. The virus is usually transmitted to humans through the bite of an infected mosquito.
According to the Centers for Disease Control and Prevention, most people infected with the virus will have no symptoms, one in five will develop a fever, among other symptoms, and less than 1 percent develop a serious, sometimes fatal neurologic illness.