Mosquitoes carrying the West Nile virus have been found in six Pennsylvania counties, along with one human case.
The state's West Nile Control Program said the mosquitoes were found Friday in Berks, Bucks, Chester, Delaware, Lancaster and Philadelphia counties.
The human case of West Nile virus was discovered in Chester County.
Friday was the last routine surveillance and reporting day for 2019, according to the state Department of Environmental Protection's website.
West Nile virus is a mosquito-borne sickness that may cause encephalitis, a brain irritation. Mild infections can produce fever, headaches, body aches, skin rash and swollen lymph glands.