Three more human cases of West Nile Virus have been confirmed in Middlesex County, according to the Massachusetts Department of Public Health.
In response, the DPH has raised the WNV threat level to “high” in the following communities: Chelsea, Everett, Lexington, Malden, Medford, Melrose, Revere, Saugus and Winthrop.
Earlier this week, DPH officials raised the threat level to “high” in Newton after a Newton woman was confirmed as having the state’s fourth human case of WNV.
Also, the threat level is being raised to “moderate” in other towns: Bedford, Burlington, Lincoln, Stoneham, Wakefield, Winchester and Woburn.
WNV mosquito cases have been confirmed in 97 towns statewide this year and the state is on pace to having the highest number of WNV cases since 2000, according to the DPH.
Last month, West Nile Virus was confirmed in Newton mosquitoes.
WNV cases are up 40 percent since last week, the Centers for Disease Control and Prevention (CDC) announced on Wednesday.
As of Aug. 28, 48 states have reported WNV infections in people, birds or mosquitoes, according to the CDC, with 1,590 cases of human infection — including 66 deaths — reported to the CDC. Of those human cases, 56 percent were classified as neuroinvasive disease, such as meningitis or encephalitis, and 44 percent were classified as non-neuroinvasive disease.