Nature’s WeChat official account on April 11th, sewage detection may be used as an early warning method for outbreaks, and early detection of signs of a comeback.

Several dozen research groups around the world have begun to analyze whether the sewage contains new coronaviruses, hoping to use this to assess the overall scale of infection in the community-given that most people do not Will be tested. Scientists say this method may be used to detect whether the new coronavirus “returns” to the community. So far, researchers have found traces of the new coronavirus in sewage from the Netherlands, the United States and Sweden.


Scientists have found traces of the new coronavirus in several sewage treatment plants in the Netherlands.

Analysis of wastewater—wastewater that enters treatment facilities through a drainage system—is a way researchers can track infectious diseases; in urine or feces Will contain related viruses, such as SARS-CoV-2.

Gertjan Medema, a microbiologist at the Dutch KWR Institute of Water Resources, said that a sewage treatment plant can treat wastewater produced by more than one million people. Sewage monitoring on this scale can predict the scale of the outbreak better than human testing, because sewage monitoring can include those who have not been tested or have only mild or asymptomatic symptoms. He has detected the genetic material of SARS-CoV-2, viral RNA, at several sewage treatment plants in the Netherlands. He said: “The health facility only saw the tip of the iceberg.”

However, the researchers said that to quantify the scale of infection of a group through sewage samples, they must first understand the feces How much viral RNA will be excreted, and then estimate the number of infections in a group based on the concentration of viral RNA in the sewage sample.

Scientists from the Queensland Environmental Hygiene Science Alliance in Australia stated that researchers need to ensure that the samples are representative, not to miss a million, and to ensure their testing methodsLaws can detect low concentrations of viruses; not only that, sewage monitoring should be operable and cannot occupy individual detection resources. (The Queensland Environmental Hygiene Science Alliance, as a research center, is responsible for providing state governments with advice on environmental health risks.)

Environmental Engineer Kyle Bibby of the University of Notre Dame, Indiana, USA Due to the closure of universities and laboratories and the lack of testing reagents (the same reagents used in clinics), some virus monitoring efforts have stalled. “We don’t want to exacerbate the global reagent shortage.” He said.


Warning signal

Infection prevention and control measures, such as controlling social distance, may be able to suppress the current pandemic, but once these measures are cancelled, the epidemic may be Make a comeback. Routine sewage monitoring may be used as a non-invasive early warning tool to remind communities of the risk of new coronavirus infection , said Ana Maria de Roda Husman, an infectious disease researcher at the Dutch National Institute of Public Health and Environment. Previously, the institute detected outbreaks of norovirus, drug-resistant bacteria, polio virus, and measles by monitoring wastewater.

De Roda Husman ’s team in the Netherlands used clinical testing to confirm the first patient with new coronary pneumonia just 4 days after being in sewage from Amsterdam ’s Schiphol Airport Traces of new coronavirus were detected. Now, they plan to expand the sampling scope to the capital cities of all 12 provinces in the Netherlands and 12 other places where there are no confirmed cases. Medema’s team detected viral RNA there before the city of Amersfoort reported an infection in the community.


Studies have shown that SARS-CoV-2 can appear in an individual ’s feces within three days of infection, and the individual develops symptoms that are severe enough to require medical attention for up to two weeks before He was formally diagnosed, said environmental virologist Tamar Kohn of the Federal Institute of Technology in Lausanne. Tracking viral particles in sewage may give early warnings to public health officials to help them decide whether to take measures such as closures. “The time difference of 7-10 days has a great impact on the progress of the epidemic.”

Bibby said that early detection that the virus has entered the community may limit the health and economic damage caused by new coronary pneumonia, especially if it breaks out again in the coming year.

Charles Gerba, an environmental microbiologist at the University of Arizona in Tucson, said that sewage monitoring has been used to evaluate the effectiveness of vaccination against poliovirus for decades. At this time, it may be possible to use this method to measure the effectiveness of interventions such as controlling social distance. He detected traces of new coronavirus in untreated sewage in Tucson.


The original article was published in the “Nature” news on April 3, 2020 with the title “How sewage could reveal true scale of coronavirus outbreak” by Smriti Mallapaty

(Originally titled “Sewage testing or helpful to assess the true scale of the epidemic”)