11 West Nile virus infections found in Philly

The West Nile virus is here. On Friday, the Philadelphia Health Department announced that it had confirmed 11 cases of West Nile in Philadelphia

Ten of those patients, eight of whom were over 50 years old, had neuro-invasive infections and had to be hospitalized. (The 11th patient only developed a fever).

None of these infections were fatal, but one out of 150 patients who catch West Nile virus can develop inflammation of the brain or spine, causing aseptic meningitis, encephalitis, or flaccid paralysis, which could be fatal.

Now, the Philadelphia Department of Public Health is spreading the word about the West Nile virus’ presence in the city and asking for the public’s help combatting the further spread of the disease. Officials urged residents to follow two key steps: wearing bug spray and dumping any standing water around their homes, which can be a breeding ground for mosquitoes.

“We all have a role in preventing the spread of West Nile Virus,” Philadelphia Health Commissioner Thomas Farley said in a statement Friday. “It’s easy to do: wear mosquito repellent and dump out standing water.”

To prevent the spread of West Nile, the Philly Health Department’s Vector Control Services program has been working to control mosquito populations. So far this year, they have treated 57,000 storm drain inlets with larvicide to prevent the species from breeding and potentially spreading West Nile, they said. Four aerosol sprays were conducted in areas of Philly where West Nile was found, they said. (See map below).

A 2018 map of mosquito pools and human infections. (Courtesy of Department of Public Health)

West Nile infections reported in Philadelphia have ranged from zero to 24 over the last two decades. The peak seasons were in 2003, 2010, and 2012, but recent years have been “relatively mild,” the Health Department said. Only three cases were reported in 2017. From 2012 to 2017, Philadelphia reported between one to six neuroinvasive West Nile Virus infections, and up to two deaths occurred per year.

But earlier in 2018, Pennsylvania Department of Environmental Protection sounded the alarm about West Nile appearing this year, stating that they were seeing the most activity in the state since the disease first appeared here in 2000.

In Philadelphia, Health Officials testing mosquito colonies this year found a mosquito with the West Nile virus in 35.8 percent of them – far higher than the historic median rate of 3 percent, and higher than past peak years of 2010 (19 percent) and 2012 (24 percent). (That number does not reflect the overall rate of Philly mosquitoes carrying West Nile virus, which has not been ascertained as of this time.) 

What is West Nile virus?

West Nile virus is a viral infection spread by mosquito bites. Though most people — 8 out of 10, according to the Centers for Disease Control and Prevention — infected do not have any symptoms, the virus can cause high fever and flu-like illness. In rare cases, people can develop severe, sometimes fatal, illness.

There are currently no vaccines to prevent, nor medication to treat West Nile virus in humans. West Nile virus can infect anyone, but those over the age of 50 are at a higher risk for more severe disease.

The first 2018 infection in Pa. was reported in July in Allegheny County, and since then, more than two dozen have since been reported, including the 11 in the Philadelphia region. 

Homeowners are urged to check any place where standing water can collect, whether that be soda bottle caps, children’s wading pools, pet food bowls or discarded tires, and dump them, to further cut down on mosquitoes breeding and spreading the West Nile virus.

Health officials also urged citizens to make sure window and door screens are well-fitted, and to use bugsprays that contain one of the following ingredients: DEET, Picardin, Oil of Eucalyptus, or PMD. Wearing long-sleeved clothes, and staying indoors at dawn, dusk and in the early evening can also reduce the risk of potential West Nile infections from mosquito bites.

Anyone experiencing unexplained headaches, weakness, and fatigue, is urged to visit a doctor.

To report mosquito problems in your neighborhood, call the Philadelphia Health Department’s Mosquito Complaint hotline at 215-685-9000. Reports will lead to inspections and possible treatment by city officials. To learn more, visit phila.gov/health.

Additional reporting by Kristin Toussaint