The Allegheny County Health Department on Monday confirmed that additional mosquito samples have tested positive for West Nile Virus. The health department will treat areas for mosquitoes in the communities of Hazelwood,

The disease causes serious illnesses in about 1 in 150 infected people, and can prove fatal. No human cases have been reported in Pennsylvania or New Jersey this year.

The person who died was identified as an older adult with underlying health conditions. So far this year, 17 human cases of West Nile have been confirmed in the county.