Will COVID-19 spread to sewage? | Science

The virus that causes COVID-19, SARS-CoV-2, usually enters humans through the eyes, nose, and mouth. However, once established in the respiratory tract, pathogens do not always remain in the respiratory system.

Recent evidence suggests that the new coronavirus may spread to parts of the body such as the intestine. The virus then uses the intestine as a starting point to enter the feces of some patients, where researchers have detected its genetic footprint.

Experts are still convinced whether SARS-CoV-2 can survive in feces or wastewater, or if feces can constitute another way of moving COVID-19 from person to person. Is not … Health authorities maintain it The risk of this mode of transmission is low..

However, when researchers race to find the answer, the SARS-CoV-2 fecal signature actually turns out to be a weapon for wielding COVID-19, where and how the disease spreads. Helps track what you are doing. By analyzing some of the genetic material of the virus in sewage, scientists can identify the population at highest risk of infection and most in need of lockdown, without struggling to sample all It may be possible. Individual test We are still short of supply.

No one can take a diagnostic test. But everyone is poo.

“This is an opportunity to better understand prevalence … [of the new coronavirus]”Is called Andrea Silberman, A civil and urban engineer specializing in wastewater treatment at New York University. “If we could sample the entire community at once, the potential benefits would be huge.”

Body journey

SARS-CoV-2 travels from person to person mainly via individual coughs, sneezes, speaking, or droplets that appear when speaking Probably breathe.. From the beginning of the outbreak, it’s clear that the virus can leave calling cards in the feces. However, whether COVID-19 can spread in this way is an open question.

Discovered by researchers and doctors Large amounts of SARS-CoV-2 RNA, Or genetic material, To feces sample Took From Infected patients,To tell Saurabh Mehandru, Mt. Gastroenterologist and immunologist at the. Ikan Medical School in Sinai. These genetic signatures remain long after the virus itself is destroyed. In an example where scientists looked for a viable virus in stools, A few, But Not all, Have Found them..

of Center for Disease Control and Prevention And World Health Organization The risk of spreading the virus via the faeces is low. So far, there have been no reported cases of COVID-19 exposed to contaminated stool.

Still, there is still no consensus on whether SARS-CoV-2 can leave the body intact. Just say “the possibilities are true” Lifuan Yuan, Veterinary University of Maryland, Virginia, is studying enteric viruses. To understand that, researchers need to investigate more patient stools and conduct controlled experiments on animal models and cells cultured in the laboratory.

Presumably, these SARS-CoV-2 RNA fragments were simply debris, and viral debris was swallowed from the respiratory tract into the digestive tract where digestive chemicals and enzymes shred them. But if the virus survives this dangerous journey through the gastrointestinal tract, it will Maybe … Infect theoretically Enterocytes, Which display Same surface protein New coronavirus Used to enter cells of the respiratory tract..

Mehandru states that intestinal SARS-CoV-2 infection is plausible because it is likely due to the large amounts of RNA in some fecal samples. However, the new coronavirus is covered by a delicate, fatty outer layer called the pathogenic envelope Sensitive to harsh chemicals— It’s like the human digestive tract. “It’s a very hostile environment,” he says. “This virus Damaged in transit.. “

If SARS-CoV-2 sometimes seeds satellite populations in the intestine, it may explain why About one third Many patients with COVID-19 have symptoms such as nausea and diarrhea. Mehandru said the fort in the gut could excrete the virus, or at least its genetic material, in the feces, hooking the car from the body.

Sewer signal

Whether or not active SARS-CoV-2 persists in human excreta, the presence of its RNA in the stool may benefit disease surveillance. In the world, researcher Now Turning To Wastewater monitoring As a means of tracking the spread of the virus in urban and suburban communities.

In areas where the toilet is connected to the sewer system, flushed waste Gradually integrated into a large pipe On the way to the water treatment facility. According to Silberman, sampling somewhere along this path provides a quick and comprehensive picture of the health of a particular city, borough or neighborhood.

Finding SARS-CoV-2 in sewers is very similar. Diagnostic test For human patients. Researchers extract genetic material from wastewater and then search a set of RNAs dedicated to SARS-CoV-2. Public health officials have previously used similar forms of surveillance, Polio, Hepatitis A, Norovirus And Antibiotic resistant bacteria..

Given that large-scale patient testing continues to stagnate, this strategy may prove to be particularly useful for COVID-19. Some infected individuals may begin to shed some of SARS-CoV-2 Before they feel symptoms,To tell Aaron pacman, Civil Engineering Engineer at Northwestern University. Homing to these sewage clues may help identify people who may unknowingly spread the disease or may give the hospital notice of an imminent outbreak. Hmm.

Early results It seems to support this theory. Researchers sampling a Dutch wastewater treatment plant have discovered that viral RNA has invaded local sewers Before the city reports confirmed cases of COVID-19.. Investigation Massachusetts Found higher than expected concentrations of SARS-CoV-2 genetic material in local sewage, suggesting that far more people were infected with coronavirus than was identified in the test.

Silberman warns that this method is still being improved and is not accurate enough to determine the number of individuals infected in a particular wastewater zone. To achieve that amount of resolution, “we need to know how much viral RNA each person is excreting,” she says. However, the amount varies from person to person and can fluctuate during the course of the disease. Currently, scientists are expanding the lens to monitor a wide range of trends in the decline of viral RNA levels over time.

“If you start seeing a virus, that’s an early warning that intervention is needed,” Pacman says. Conversely, the gradual reduction of pathogens in urban wastewater could inform local authorities that the blockade is functioning and help residents along a tentative path toward resumption.

Virginia pizzaAs an epidemiologist at Yale University, wastewater monitoring helps to allocate tests and other limited resources to where they are most needed. “It’s easier than going out and testing all the inhabitants,” she says. But even if the community tests positive for sewage, researchers still need to find out who has the coronavirus in their body and who doesn’t. “This is not a substitute for individual tests,” says Pizzer.

Universal clean water

If it turns out that the new coronavirus can spread through feces and contaminated water, the risk is Very low in parts of the world with good hygiene.. Wastewater is usually treated with harsh chemicals, SARS-CoV-2 is unlikely to persist in sewageSays Silberman. In addition, the virus must infect living cells in order to replicate. If they can’t find the target, they disappear.

But experts are worried that people who live in areas without adequate sanitation may be at increased risk of getting the virus from their wastewater. “The focus of all our containment efforts was very localized,” says Pacman. “Water is a long-distance pathway. It can spread disease much sooner than expected.”

Other coronaviruses Infects animals like pigs It is known to be transmitted via feces. You may have played the stool too Small role For a small handful SARS Outbreaks that started in 2002 say E. Susan Amilian, Rice University epidemiologist. Several people living in an apartment in Hong Kong may have been infected when a faulty sewage system aerosolized a waste plume.

To date, there is no evidence that the same applies to SARS-CoV-2. However, “when the virus is excreted in the feces in its viable form … Billions WHO Sanitary facilities not available“Silverman says. This basic need is particularly lacking in places like Sub-Saharan Africa, South Asia and East Asia.

In America Not everyone Clean water is available on a regular basis. And many communities lacking clean water Already vulnerable to illness It is overcrowded due to infrequent access to health care and a high incidence of other health conditions. they again, Many pathogens It is known to be carried from place to place by contaminated water. Many of these concerns are Navajo Nation, COVID-19 cases and deaths Keeps swelling..

“We are on the other side of this pandemic Widening gap Between what I have and what I don’t. ” Matthew Miller, A biologist at the University of Oklahoma. “It’s a very cool reality.”