Data shows that Covid cases in the US have peaked just weeks after the last uptick in infections.
Scientists tracking the spread of the virus by testing sewage nationwide say the number of positive samples has fallen by 5 percent in the past week.
Dr. Cristin Young, an epidemiologist involved with the wastewater monitoring project, said: “All fingers crossed, this wave is leveling off and may be subsiding.”
If true, it would put an end to several months of rising infection levels – spurred by two highly contagious new variants, Eris, or EG.5, and Pirola, or BA.2.86.
The sharp increase – which never translated into a major increase in deaths or intensive care admissions – left many hospitals, schools and businesses requiring face masks again.
Americans wear face masks as they wait in line to vote in the 2020 presidential election. Some colleges and businesses are reinstating mask mandates as Covid cases rise in the US
Scientists tracking the spread of the virus by testing sewage nationwide say the number of positive samples has fallen by 5 percent in the past week (shown)
The decline was driven by declining positive sample rates in mid-Atlantic states such as Virginia and Maryland. In contrast, collection sites in the Midwest and Northeast are showing a steady increase in Covid spread
Dr. Young and his team at Biobot Analytics are using wastewater from 257 locations across the country to track the spread of the virus – a technique developed during the pandemic.
Their results show that the daily number of new Covid cases in the week to September 13 was estimated to be around 60,000, a drop of around 5 per cent in a week.
The decline was driven by declining positive sample rates in mid-Atlantic states such as Virginia and Maryland.
In contrast, collection sites in the Midwest and Northeast are showing a steady increase in Covid spread.
Biobot’s findings are supported by surveillance in North Carolina, said Jessica Schlueter, associate professor in the department of bioinformatics and genomics at the University of North Carolina at Charlotte.
She is responsible for testing wastewater at a dozen locations in her state.
The increase in Covid wastewater samples over the past six months “appears to be peaking and starting to decline,” she said, which could mean a drop in cases.
Official data shows the pace of increase in Covid hospital admissions has also slowed, after rising 7.7 per cent in the most recent week data is available – marking the slowest rise since early July, when hospital admissions reached a record low.
The latest data shows there were 20,538 Covid admissions to US hospitals in the week to September 9.
There are also signs that Covid-19 deaths are starting to level off.
A total of 844 were recorded in the week to August 19, the latest available. Data for the following week is incomplete, but currently indicates that 860 fatalities linked to the virus were recorded during this period – an increase of 1.8 percent.
But not everyone is so optimistic.
Dr. Amy Kirby, head of the CDC’s wastewater monitoring program, shared NBC News: “We’ve seen enough data over the years to know that we’ll see some increases around the time school starts.”
These are expected to “plateau” and then come down again before another winter surge, she warned.
Wastewater surveillance has “demonstrated benefit as a robust, highly adaptable platform for community-level surveillance for SARS-CoV-2 transmission,” according to a report from the CDC last week.
Weekly Covid hospitalizations are increasing, according to the latest CDC data
Deaths are starting to decline again, but are rising from near historic lows
With Covid testing largely scrapped, wastewater surveillance is one of the few ways officials can track the spread of the virus in the US.
In a pilot study during last year’s flu and RSV season, concentrations of RSV and influenza in wastewater samples from three major Wisconsin cities were collected and compared to the number of emergency room visits related to the viruses in the area .
Testing for flu and RSV is not widely practiced, so wastewater can be an important early warning sign.
Anyone infected with a virus sheds small fragments of their DNA in their poop.
Higher concentrations in sewage were associated with more emergency room visits for influenza and RSV.
Higher levels of the viruses in wastewater often preceded ER visits and indicated a surge was coming, the CDC said.
This could be used as an effective alert system for emergency medical personnel of an impending outbreak in the area.
“Hopefully with updated vaccinations we won’t see a big winter surge like in the past,” Dr. Kirby said. “But it’s actually too early to tell.”
