Acknowledging factors that complicate the accuracy of official case counts, Dr. Debra L. Bogen, director of ACHD, announced at a March 16 press conference that the health department has begun to move away from viewing case numbers as a primary metric to assess the extent of community spread of COVID-19.
“As our case data becomes less usable because more and more people are, fortunately, able to test themselves at home, we are less able to rely on that as a source of information,” Bogen said at the press conference, “and hospitalizations lag so we can’t use that in real time.”
“We are really switching from trying to prevent all cases to trying to prevent severe outcomes — hospitals and deaths — and trying to protect the health care system so that they can do the other important work out there,” Bogen told the Pittsburgh Post-Gazette on March 17.
Going forward, ACHD plans to release weekly reports of COVID data every Thursday, which will include familiar pandemic measurements, such as numbers of hospitalizations, deaths, and new cases, as well as less-familiar metrics pertaining to the concentrations of COVID-19 found in the county’s wastewater.
Because people infected with COVID-19 shed the virus in their feces before showing symptoms, the CDC says wastewater monitoring can be an effective early warning indicator of increasing COVID transmission in a community.
“Wastewater is a wonderful opportunity to look at our population as a whole and how much virus we are shedding into our sewershed."
“Wastewater is a wonderful opportunity to look at our population as a whole and how much virus we are shedding into our sewershed,” said Bogen. She added that ACHD has been collecting samples of the county’s wastewater three times a week and sending them to a Fla. lab for analysis, although they plan to develop local testing capacity.
ACHD hopes wastewater monitoring can help bypass some of the problems presented by official COVID testing data. In contrast to official case numbers, which require individuals to go out and get a COVID test in order to make it into health department data, individuals don’t have to opt into wastewater monitoring. Wastewater also captures the viral shedding of asymptomatic people, who may never think to get tested for COVID in the first place.
Dr. Bogen said that wastewater monitoring can provide data on 80% of the population of Allegheny County.
“We know from our historical data that our case data really overlies very nicely with the wastewater data, so we can see how that will predict what’s happening in the future,” said Bogen.
Beyond that, ACHD continues to encourage people to get a booster, if they haven’t already. “It’s really important for people to get that third dose,” said Bogen.
“This is not a farewell to the pandemic,” Dr. Bogen stressed. “We are not claiming victory or shifting to treating COVID like we do influenza. COVID is not done. We may face more surges. We may ask people to wear masks again for some limited time. New variants may emerge … The health department will continue to analyze data, provide guidance, do our best to anticipate trends, and keep people as safe as we possibly can.”