The West Nile virus has already been found this summer in mosquitoes in areas close to the Saucon Valley, according to the PA West Nile Virus Program, which monitors the spread of the disease.
On July 3, a sample mosquito in Quakertown borough tested positive for the virus. And on June 26, a mosquito in the City of Bethlehem tested positive, the website reports.
West Nile-positive mosquitoes have been already recorded in every southeastern Pennsylvania county this year, with higher concentrations recorded in the southernmost counties near the Maryland border.
A total of 15 mosquitoes in Bucks County have tested positive, three in Northampton County have tested positive and four in Lehigh have been found to carry the virus.
No human cases of West Nile virus have been reported in the state as of July 14.
In 2017 a total of 20 human cases of West Nile virus were reported in Pennsylvania, including one case in Northampton County and one case in Lehigh County, according to historical data from the PA West Nile Virus Control Program
The virus was found in a mosquito in Lower Saucon Township in late August 2017.
Typically reported cases rise as the summer progresses, peaking in late summer.
The virus can cause a variety of symptoms in humans, including headache, body aches, joint pains, vomiting, diarrhea and rash, although most infected people (about 80 percent) do not develop any symptoms, according to the U.S. Centers for Disease Control.
In rare cases the virus can lead to encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes around the brain and spinal cord). Among people who develop these serious symptoms approximately one in 10 will die, according to the CDC.
“Severe illness can occur in people of any age; however, people over 60 years of age are at greater risk,” the CDC says. “People with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease and people who have received organ transplants, are also at greater risk.”