BOSTON (CBS) – The state health department announced four more cases of West Nile Virus in Massachusetts. There have now been seven cases in the state this year.
Three men, one in his 40s, one his 60s and one in his 80s were exposed in Middlesex County.
A female under the age of 19 was exposed in Bristol County.
Health officials have elevated Cambridge, Newton, Somerville and Watertown to high risk for West Nile Virus.
WNV is usually transmitted to humans through the bite of an infected mosquito. Most WNV virus activity this year has been focused in an area around Boston and includes parts of Norfolk, Middlesex, and Essex counties.
Health officials recommend using insect repellent, avoiding being outdoors at dusk and dawn and covering bare skin to prevent becoming infected.