If the last two years have taught us anything, it’s that testing for viral diseases is complicated. Tests are sometimes difficult to do, as in the early days of COVID-19. And even if people have access to testing, they may not feel they need it. People with COVID-19 usually no symptoms and may not always know to be checked. And now, with the availability of home self-testing methods, most people test themselves and don’t report results. With other diseases — such as monkey smallpox—Blurs around the disease and the most affected group can prevent access to testing.
These restrictions hinder health authorities’ ability to learn more about infectious diseases and control their spread. If you can’t detect the problem, you can’t direct resources to help fix it.
Wastewater analysis can help with some of these problems. Scientists have been tracking COVID-19 through wastewater since the beginning of the pandemic, and now they’re doing the same for monkeypox. A new program led by researchers at Stanford University, Emory University, and Verily, a company part of Alphabet Inc., is tracking smallpox cases in monkeys by analyzing wastewater from 41 communities in 10 state. To date, they have detected monkeypox virus in 22 of them. As the number of smallpox cases in monkeys across the country continues to rise, such information is proving valuable as doctors and patients grapple with testing challenges. “We have now detected monkeypox DNA in the sewers before any cases were reported in those counties,” said Bradley White, senior scientific officer at Verily. The team is planning to publish their first findings from their monkey smallpox study in a pre-print. Other academic and public health groups are working with their local wastewater facilities to monitor the virus, but this program, known as Wastewater SCANfocus on getting a national picture of ongoing cases.
The data is shared publicly on website hosted by Stanford, and the team is sharing its findings with the US Centers for Disease Control and Prevention (CDC).
Because the wastewater is aggregated from thousands of people, it provides an ideal, anonymous way to detect virus levels in a community. “We are capturing cases even when people are asymptomatic,” said Marlene Wolfe, professor of environmental health at Emory and co-investigator of WastewaterSCAN. “When testing capacity is limited and there’s stigma associated with this disease, it’s really powerful to measure the extent to which a population of infections is unaffected by those things.”
Another reason why sewage is such a sophisticated way to track monkeypox has to do with the fact that it contains sewage not only from urine and feces, where the virus can be excreted, but also from water. foam and water escape while people brush their teeth and shower. Because monkeypox virus is active in skin lesions, such secretions are a particularly effective means of trapping and detecting the virus.
Researchers have been analyzing wastewater for decades, most notably during the 1940s, to monitor polio in the United States. The COVID-19 pandemic has proven its utility on a large scale. Studies have shown that waste samples often show signs of SARS-CoV-2 up to a week before regional clinics start recording positive cases. Wastewater can even detect new variants of SARS-CoV-2—Something a quick test can’t do.
At the end of 2020, the CDC released National wastewater monitoring system (NWSS), the first federal system track an infectious disease pathogens — in this case, SARS-CoV-2 — in wastewater. It is an attempt to standardize the way wastewater is collected, analyzed, and interpreted. The NWSS currently includes data from local programs — like WastewaterSCAN — and cities with their own tracking systems. For example, New York City’s Biological Surveillance Program has been testing wastewater for signs of SARS-CoV-2 since February, and now 11 hospitals in the group will start scanning for smallpox in monkeys and poliowas detected in New York City wastewater.
When monkeypox cases first started appearing in the US, researchers at Stanford, Emory and Verily saw an opportunity to apply sewage lenses to the disease, especially because of testing for the disease. Smallpox in monkeys is not widespread. They tracked SARS-CoV-2 at several locations in California through Drain Coronavirus Alert Network (SCAN) as of November 2020, and added analyzes of other viruses, including influenza and RSV. As cases of monkeypox began to spread around the world, and while access to testing remained limited, they added that virus to their investigation and expanded their network to include more sites around the country. WastewaterSCAN was born.
Wolfe said the team’s background in isolating the bacterial genetic material made it relatively easy to create the right test to detect monkeypox virus in mid-June. They targeted a portion of the relatively unique monkeypox genome, and the probe successfully identified the virus in their laboratory tests. However, White says, “the first few tests that we ran on wastewater samples didn’t pick up anything.” That could be because the virus concentration in the wastewater at that time was too low. While the WastewaterSCAN probe is designed to collect very dilute amounts of virus, at the time of testing there were very few cases in northern California. On June 19, WastewaterSCAN began testing samples supplied daily from two treatment plants in the San Francisco area. The next day, both sites tested positive for monkeypox.
Read more: What it really feels like to have monkeypox
The genetic material of the monkeypox virus is different from the genetic material of SARS-CoV-2 because it is in the form of DNA, while the COVID-19 virus and all of the team’s previous tests were against RNA. However, White says, “DNA is much more stable than RNA, so as long as genetic material is extracted from the sample, we’re pretty confident that if humans shed viruses in wastewater, they’ll be able to get rid of the virus.” I will find it eventually.”
Scientists say there are still some important unanswered questions about monkeypox in wastewater. They don’t have enough data to say with certainty how much time sewage can give health officials about rising cases, compared with testing at clinics and hospitals. They are also continuing to analyze the data to better understand how much virus needs to circulate in a community, or how many cases need to accumulate in a given area, before their analysis can detect it. for signs of viruses in wastewater. That could give doctors an important head start in preparing enough tests, vaccines and treatments before cases peak.
The WastewaterSCAN team is now applying what they’ve learned from COVID-19 and monkeypox to explore ways to monitor flu, RSV, and other seasonal illnesses. In the case of RSV, a respiratory infection that often infects infants, knowing where cases are starting to circulate can help doctors treat the most vulnerable children with antibiotics. monoclonal organisms before they are exposed, and thus save them from contracting a potentially dangerous disease.
The key to having such a national system, however, is coordination among partners who share their findings, says Wolfe. “Having a network of sites using the same collection and analysis methods so we can compare data gives us a national picture of what is going on,” she said. “We want more federal investment in systems like this.”
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