Five dead birds found in Mercer County have tested positive for West Nile virus, the state Department of Health said Thursday.

Testing positive were crows found in Fredonia, Mercer, Sharon and Pymatuning Township and a blue jay found in Hermitage.

Those results are added to previous confirmations of the virus in birds found in Mercer and East Lackawannock, West Salem and Hempfield townships.

No new counties were added to the list Thursday, but 21 counties where the virus previously was found added confirmed cases in samples of chickens, blue jays, crows and mosquito pools.