Polio and monkeypox left out of Philly's wastewater testing program

Since polio was found in wastewater samples in New York last month, health officials have tracked the virus from sewage systems in two southeastern counties, Rockland and Orange, to New York City.

• But detecting viruses like polio won't be as easy in Philly.

Driving the news: Philly started wastewater surveillance for COVID-19 earlier this year, but the city cannot expand the program to test for other infectious diseases at this point in time, James Kyle, a health department spokesperson, told Axios.

• That's due to limitations around the federal funding that pays for it, Kyle said.
• "COVID wastewater testing is funded through federal COVID funds, and currently there is no funding for monkeypox or polio," he said.

The big picture: While there was some level of wastewater surveillance in the U.S. before the pandemic, COVID supercharged it by prompting the creation of the National Wastewater Surveillance System, Axios' Tina Reed and Arielle Dreher report.

• Several universities have since banded together to build their own networks of wastewater testing, such as Stanford-based WastewaterSCAN, which has expanded its work to other viruses like influenza A, respiratory syncytial virus (RSV) and now, monkeypox.

How it works: Virus levels in wastewater typically rise several days before an area sees an increase in clinical cases, providing a harbinger of disease spread.

• But wastewater sampling is not perfect. The sludge can't be used to pinpoint individual cases, so it isn't viewed as a replacement for test-and-trace and other public health tools.
• Experts say the size of the sewershed that samples are drawn from can lead to more diluted results.

Of note: No polio cases have originated in the U.S. since 1979, per the CDC.

• While a confirmed case in New York has prompted concerns among a pandemic-weary public about the resurgence of the disease, experts say the U.S. is highly protected from the widespread transmission of polio, at least in areas that are highly vaccinated.

Zoom in: "Virtually every neighborhood" in Philadelphia exceeds the 80% rate of polio vaccination that is believed to be necessary for herd immunity, city health commissioner Cheryl Bettigole told Axios in a statement.

• But in some neighborhoods in South Philly, fewer than 60% of children are vaccinated against polio.
• The citywide polio vaccination rate for children under 5 is 90%.

Between the lines: Philly has seen child vaccination rates for recommended vaccines drop during the pandemic.

• The school district requires the polio vaccination for K-12 students.

Meanwhile, monkeypox continues to spread in Philly, with cases eclipsing 200 as of last week, according to the city's online dashboard.

• The CDC issued new guidance last week saying that the risk of monkeypox transmission among children is low.

What's next: The city is exploring the possibility of testing for monkeypox with the CDC, Kyle said.

• "But, again, there are rules regarding how we can use grant funds and help from the CDC would be very helpful," he said.