United States: Health experts in Philadelphia are warning people to be extra careful after mosquitoes carrying the West Nile virus were found near Pennypack Park in the city’s Northeast area.
The city’s Public Health Department checks for this virus regularly. Their recent testing found the first infected mosquitoes of the season. That led to a health alert on July 7, asking doctors in the area to stay alert and be ready to test patients for West Nile until the end of October—or sooner if the weather gets cold fast.
Doctors Told to Watch for Symptoms
Doctors and nurses are being asked to keep an eye out for certain signs in patients—especially if someone has unusual symptoms like brain swelling or spinal issues. If they see anything suspicious, they should test for West Nile virus.
Any cases they find, even if they’re just suspected, should be reported right away to the city’s health department, according to the reports by inquirer.com.
Talk to Your Doctor About Mosquito Safety
Health workers are also being reminded to talk to patients about ways to prevent mosquito bites. This is especially important for people who work outside or are planning to travel to warmer areas where mosquito-borne illnesses are more common.
Most People Don’t Get Sick—But Some Do
The good news is most people who are bitten by infected mosquitoes won’t get sick at all. Even among those who do get infected, many will feel fine. According to Emily Kehoe, the city’s expert on mosquito-borne diseases, only about 1% of people get seriously sick. But for that small group, the illness can be dangerous—and sometimes even deadly.
The virus can cause swelling in the brain or around the spine. Older adults and people with weak immune systems are at higher risk of these serious problems.
Around 20% of infected people might get flu-like symptoms such as fever, rash, upset stomach, vomiting, headaches, tiredness, body pain, or joint aches.
There’s no vaccine or exact medicine for West Nile. The usual advice is to rest, drink fluids, and take something for the pain. Most people recover without issues.
Between 2020 and 2024, the city reported 4 to 9 serious cases each year, and at least one death every year. As of now in 2025, no cases have been confirmed yet in Philadelphia.
Other Infections to Be Aware Of
West Nile isn’t the only concern. Other rare viruses spread by mosquitoes or ticks—like Powassan virus or Jamestown Canyon virus—have also been found in the area in recent years, as reported by inquirer.com.
But don’t panic—these are still very rare in Philadelphia.
More Mosquito Testing Underway
Every year, the health department finds mosquitoes carrying West Nile virus in various parks. Pennypack Park is often one of the first spots. It’s a huge park with woods, open fields, and wetlands—perfect breeding ground for mosquitoes.
As the city keeps testing other areas, they expect to find more infected mosquitoes over the next few weeks.
How You Can Stay Safe
Here are some simple ways to protect yourself and your family:
- Use mosquito repellent with DEET, picaridin, or oil of lemon eucalyptus.
- Wear long-sleeved shirts and pants when outside, especially in the evening.
- Make sure your windows and doors have screens that fit well.
- Get rid of standing water around your home—empty buckets, flowerpots, birdbaths, and plastic kiddie pools every day.
- If you have mosquito problems, call the city’s Mosquito Hotline: 215-685-9000.
- If you find a dead bird, call the PA Game Commission at 833-742-9453. Some birds can carry the virus too.