To prevent the spread of West Nile virus, the Philadelphia Department of Health is spraying parts of Germantown with a mosquito insecticide Monday night.
The city’s Vector Control staff will apply the treatment around dusk in Wister Woods and Wakefield Park. Mosquito samples from the area have shown that adult mosquitos potentially carry the disease, so the spraying is a preemptive measure.
Only certain species of mosquitos carry the West Nile virus, which can cause encephalitis — inflammation of the brain — when transmitted to humans. There are more than 3,000 mosquito species worldwide, but only 200 in the United States and 60 in Pennsylvania. In urban areas, the most common species is the northern house mosquito, which is thought to transmit the most West Nile cases in Pennsylvania, according to Penn State Extension…