BOSTON (AP) _ The Massachusetts Department of Public Health says a Middlesex County man is the first person to contract West Nile virus in Massachusetts this year.

The agency says the unidentified man in his 40s was diagnosed following testing that was completed Thursday.

The Department of Public Health is trying to determine where the man most likely was exposed to infected mosquitoes. An assessment of the risk areas of West Nile virus areas will depend on the findings.

State Public Health Veterinarian Catherine Brown says Massachusetts is in peak season for possible West Nile virus infection for people.

Six human cases of West Nile virus were recorded in Massachusetts last year. It's usually transmitted to humans by a bite by an infected mosquito.

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