West Nile virus detected in Radnor Twp. park in Delaware CountyOfficials are reminding people to take precautions against mosquito bites after West Nile Virus was detected in a park in Delaware County. Officials are reminding people to take precautions against mosquito bites after West Nile Virus was detected in a park in Delaware County. Officials are reminding people to take precautions against mosquito bites after West Nile Virus was detected in a park in Delaware County. RADNOR TWP., Pa. (WPVI) -- Officials are reminding people to take precautions against mosquito bites after West Nile Virus was detected in a park in Delaware County.