First Human Case Of West Nile Virus In Massachusetts This Year Is Woman In 80's From Middlesex County

BOSTON (CBS) – A woman in her 80's is the first human case of West Nile Virus in Massachusetts this year, the state announced Wednesday.

According to the Department of Public Health, she was likely exposed in Middlesex County, which is currently at a moderate risk level.

The state did not identify the woman or the town where she lives.

"There are no risk level changes associated with this finding; there have been no deaths this year associated with WNV," DPH said in a statement.

Acting Public Health Commissioner Margret Cooke said West Nile risk has been slow to increase this year. But, even though it's late in the season, the agency said the high amount of rain in July and the recent hot weather have led to a boost in the population of the Culex species of mosquitoes, which is known to spread West Nile.

There were five human cases of West Nile virus in Massachusetts last year.

The virus is usually spread through bites from infected mosquitos. It can cause a mild fever or more serious diseases like encephalitis or meningitis.

Most people infected will have no symptoms but people over 50 are at higher risk for severe disease, according to DPH.

West Nile Virus was first identified in the U.S. in 1999. For more information, click here.