Seventh human West Nile virus case reported in Mass.

A seventh human case of West Nile virus this year has been confirmed in Massachusetts.

The Massachusetts Department of Public Health announced on Friday that a man in his 60s was exposed to West Nile virus in Worcester County.

As a result, the risk levels for West Nile virus were raised to moderate in most of the state, the department said. Dukes and Nantucket counties as well as Provincetown and Truro remain at low risk.

Risk levels continue to be high in Boston, Brookline, Cambridge, Chelsea, Everett, Malden, Newton, Revere, Somerville, Watertown, and Winthrop, officials said.

The virus was first detected in mosquitoes in the state on June 16. Since then, 370 mosquitoes with the virus have been detected in Barnstable, Berkshire, Bristol, Dukes, Essex, Franklin, Hampden, Hampshire, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester counties, the department said.

“Because some risk will continue until the first hard frost, I want to encourage everyone to keep using mosquito repellent and take other protective measures, such as wearing long sleeves and pants to reduce exposed skin when spending time outdoors,” Public Health Commissioner Robbie Goldstein said in the announcement.

To prevent contracting West Nile virus, wear insect repellent when outdoors, especially from dusk to dawn, and wear long clothing, the department said. At home, drain standing water where mosquitoes could lay eggs and install or repair window and door screens.

There have been no animal cases of the virus this year, officials said.

The state maintains an online map of where the risk of West Nile virus is highest in the state. The Department of Public Health will provide an update on the status of the virus in the state every Friday.