Wastewater monitoring becomes more targeted in the search for poliomyelitis, monkeypox and Covid-19
In the United States, some disease sleuths are scaling back their wastewater monitoring efforts to focus on specific buildings and identify hotspots for a growing list of diseases.
“Some wastewater monitoring is done at the community level, and some at the building level, which is a little more nuanced in terms of message targeting,” said Lori Tremmel Freeman, executive director of the National Association of County. and municipal health officials.
“For example, in some of our jurisdictions they will monitor a large hotel or a prison,” she said. “If it spawns there, you can target messaging directly to that building.”
A building-level wastewater monitoring approach is underway at all 11 hospitals in the NYC Health + Hospitals integrated healthcare system in New York City.
“With rapid testing increasing and federal funding for Covid response declining this spring, sewage testing was an affordable and easy way for us to track the presence of Covid in the community without the need for patients to pass. a test,” Dr. Mitchell Katz, president and CEO of NYC Health + Hospitals, said in the announcement. “Now, with the arrival of monkeypox and polio in New York, we have a system in place to test for these viruses and use that data to inform our response.”
‘A good secondary backup’
The health system‘s surveillance program successfully identified Covid-19 and influenza viruses in wastewater from its NYC Health + Hospitals/Elmhurst hospital up to two weeks before viral infections were clinically identified among hospital patients, said Leopolda Silvera, global health assistant at NYC Health + Hospitals/Elmhurst.
Using data from the sewage tests, “we were able to say about 10 to 14 days before when we’re going to see our patients coming in sick,” Silvera said.
“People clear the virus when they use the bathroom,” she said. “So if we test our sewage, then we can tell whether or not there is an increase in the virus in the community at that particular time. And then it ends up showing when people start showing symptoms 10 to 14 days later.”
Silvera described wastewater monitoring data as giving clinicians a warning signal of a potential increase or decrease in disease, which can help inform efforts to prevent or treat disease and increase staff and supplies to meet needs.
“If we can get direct tests from our patients, like our Covid tests, that’s our primary way of being able to treat and know what’s going on with our patient population,” she said. “But having our sewage monitoring is a good secondary safeguard for us to know what’s going on in our community and so we can plan accordingly.”
Seeking to understand in waste water
“Sewage monitoring, the reason it works so well is because everyone in the community contributes their sample to the sewer system daily,” she said. “For some places it could be that most of the population of the county contributes to that one factory, and for some places it might be that even in a single city there are multiple factories that cover different parts of the population. . “
Then, of course, there could be building-level monitoring, like in a hospital.
Sampling wastewater at different levels within a community can range from “the treatment plant being the highest level down to an individual building,” Wolfe said. “There is also a kind of intermediate level, which is in the sewer network.”
Since then, sewage monitoring has been used to help track infectious diseases globally – but the technique was far from common before the emergence of Covid-19. This coronavirus is the first respiratory virus tracked with sewage, Wolfe said.
“This Rockefeller survey was really well done, but most of the surveys were done before the Omicron surge. This surge was a time when we anecdotally saw a significant increase in interest from health services public using the information and the media and the public showing interest in the data as a trusted source,” Wolfe said.
She hopes that wastewater monitoring can continue to be used as a public health tool.
The WastewaterSCAN initiative, based at Stanford University and completely separate from the CDC system, was launched in November 2020 to analyze wastewater samples for SARS-CoV-2, the virus that causes Covid-19 . Since then, the program has expanded to monitor more treatment plants and track more pathogens.
Since last week, the initiative – which involves a partnership between universities, nonprofits and research firm Verily – has been monitoring 48 treatment plants in 16 states for the coronavirus and its BA.4 subvariants and BA.5, as well as monkeypox, influenza A and respiratory syncytial virus.
When new threats emerge, it’s “relatively easy” to use sewage samples from the initiative to immediately test whatever that threat is, Wolfe said.
“That’s what we’ve been able to do recently for monkeypox, which was really exciting because we were able to deploy it very quickly, and we’ve seen in a number of places, including Atlanta, that we have detectable monkeypox DNA in the sewage from when we started surveillance, which was quite early in the outbreak,” she said. “That’s the benefit of having this kind of population-level network that allows us to talk about general trends in infectious disease outbreaks.”
“If you’re not looking for something, you won’t see it”
Wastewater monitoring proved useful at a time when it was critical to monitor pathogens not typically seen in the United States, such as poliomyelitis and monkeypox, said Dr. Daniel Rhoads, co-chair of the College of American Pathologists Microbiology. Committee.
Clinically, in the United States, “we stopped testing for polio because the polio was gone. We never tested for monkeypox because it’s a zoonotic disease in an endemic area of Africa, so we didn’t even need to worry about it one day today,” said Rhoads, who is also a pathologist at the Cleveland Clinic in Ohio.
Still, wastewater monitoring “opens our eyes collectively – in medicine, public health and society – and makes us realize that if you’re not looking for something, you won’t see it,” Rhoads said.