What does the discovery of COVID-19 virus in wastewater in multiple countries mean?

Experts from the Federal University of Santa Catarina in Brazil announced locally on the 2nd that they found the novel coronavirus in sewage samples from Florianópolis, the capital of Santa Catarina state, in November. 。

This discovery is two months earlier than the official announcement of the first confirmed case of COVID-19 in the Americas —in 1 Month 21 Day, the United States confirmed its first case—and three months earlier than the Brazilian government's announcement of the first confirmed case at the end of 2 Month.

In addition, the novel coronavirus has been detected in wastewater in many parts of the world. June 18 On the Day, a study by the Italian Higher Institute of Health also showed that the novel coronavirus RNA was detected in wastewater samples from Milan and Turin, two cities in northern Italy, in December last year. 。

6 Month 26 Day, the University of Barcelona also issued an announcement that a research team led by the university's leadership detected the novel coronavirus in wastewater samples collected in 3 Month last year in Barcelona. In addition, traces of the novel coronavirus have been detected in sewage in the Netherlands, the United States, and Sweden.

“ If the research results are correct, it indicates that the virus may have been circulating much earlier, but it was not discovered. Perhaps the virus was not highly contagious at that time, and its contagiousness increased as it spread among the population. ” Wang Guangfa, chief physician of the Respiratory Department of Peking University First Hospital, commented on the detection of the novel coronavirus in wastewater.

“ The detection of the novel coronavirus in wastewater most likely indicates that there has been a population infection with the novel coronavirus in that area, and the contaminated wastewater was directly discharged without disinfection. ” Yu Chengbo, chief physician of the Department of Infectious Diseases at the First Affiliated Hospital of Zhejiang University School of Medicine, once said in an interview with the Health Times.

Many studies have shown that the coronavirus genome exists in the fecal excretions of COVID-19 patients, and the virus genes will eventually mix into wastewater. This is the theoretical basis for studying the COVID-19 epidemic based on wastewater.

In February, academicians Zhong Nanshan and Li Lanjuan's teams respectively isolated the novel coronavirus from fecal samples of COVID-19 patients, confirming that live viruses do exist in the patient's excrement. Theoretically, the novel coronavirus cannot survive for a long time in wastewater, but the wastewater was stored frozen. The specific conditions are unknown, so the possibility of survival cannot be completely ruled out, but it at least indicates that there were once virus corpses.

2020 Year 6 Month 15 Day, a joint report titled "Analysis of Urban Drainage Network Prevention and Control Measures during the COVID-19 Epidemic" released by the School of Basic Medicine, Fudan University, and the Shanghai Municipal Urban Planning and Design Research Institute mentioned that the novel coronavirus can be completely inactivated after household sewage is disinfected with sodium hypochlorite and other effective disinfectants at wastewater treatment plants.

Although designated isolation hotels do not have centralized sewage treatment facilities, the virus can also be promptly disinfected by adding sodium hypochlorite tablets for sanitation and disinfection to indoor flush toilets.

Chief Physician Yu Chengbo also reminded that “ sewage in medium- and high-risk areas must undergo strict disinfection treatment before discharge. Individuals must also minimize contact with sewage, and water sources must be strictly treated water. ”

(Source: Health Times)