The signs are already up. At the airport and on SEPTA buses and Regional Rail trains, the city’s Department of Public Health has posted ads zoomed in on a mosquito with the warning, “Keep These Suckers Out.” Underneath, a slogan reads, “Fight the bite. Prevent Zika.” In another ad, the Department of Health warns, “Mosquitoes aren’t the only ones that spread Zika. Wear a condom.”
The department’s goal is to get the word out quickly in hopes of curbing a Zika problem. While Philadelphians need not worry as much as residents of southern states, the disease is expected to be a bigger issue than last summer. Of the approximately 200 cases Pennsylvania has experienced since late 2015, about 25 percent were in Philadelphia. Steve Alles, bioterrorism and public health preparedness manager for the Department of Public Health, said he expects that number of infections to rise this summer compared to last year.
“The biggest concern we have,” he said, “is not letting Zika get into our own mosquito pools.”
Philly does not have the mosquito that’s been carrying Zika, the Aedes aegypti. Every one of the 50 or so cases Philly saw last year came from people who contracted the virus during a visit to an infected country.
“The way we could get a Zika outbreak here,” said Dr. Kathleen Hall Jamieson, director of the Annenberg Public Policy Center at Penn, “is through our airport.”
The CDC expects the Aedes aegypti to carry the virus into parts of the southern United States, like Florida, Texas and other Gulf states. This breed of mosquito has been found farther north in rare cases, including once in Bucks County.
Philadelphia does have the Asian Tiger mosquito, known as the Aedes albopictus. It’s the same genus as the aegypti but a different species. It can carry Zika but would have to get it from a host.
So when Alles speaks of the concern, he’s referring to the possibility of Philadelphia’s Asian Tiger mosquitoes contracting Zika by biting somebody who returns from a southern state or foreign country with the virus. For every case last year, Zika patients were successfully prevented from spreading the virus in that fashion.
To reduce the possibility of Zika-carrying mosquitoes, which again are highly unlikely in Philadelphia, Jamieson recommends being mindful of standing water and making sure screens in houses are repaired. Another concern regarding Zika here — and elsewhere — is the spread of the disease through sexual contact. Both men and women can spread it sexually.
About 80 percent of people who contract Zika show no symptoms, but they can still pass on the virus. Those with symptoms experiencing a sickness similar to the flu (here’s the CDC’s guidelines on Zika).
Pregnant women or women about to become pregnant face the greatest risk. They can give birth to children with microcephaly or other development conditions. Last year, the CDC tracked 442 pregnant women in the US who had Zika and six percent had a child with Zika-related birth defects.
“Though it will have low impact on our city,” Alles said, “it will have high impact on people that get the disease.”
Jamieson said the Health Department’s warnings about practicing safe sex after visits to infected areas and controlling the mosquito population are important to make people aware of these risks. She recommends making sure screens on windows are prepared and preventing mosquitos from breeding in watery areas.
“I pass West Philly and see tires on the side of the street,” she said. “If I’m in that community I should tip those tires or they’re going to gather water. These mosquitoes can breed in a bottle cap.
“We don’t know the extent to which we are vulnerable. We do know the preventive actions to take are good things to do anyway because we don’t want to breed mosquitoes.”