Vol.40  「New Frontier in Infectious Disease Surveillance: Wastewater Test for COVID-19」

Last Updated 22 April 2022. Cellspect Co., Ltd.

After the outbreak of Covid-19, wastewater surveillance, a new tracking system, has begun to play a critical role in the field of public health. 

In a March 2020, a study published in The Lancet Gastroenterology and Hepatology confirmed that confirmed that the novel coronavirus can appear in feces within three days of infection, which is much earlier than the time required for people to develop symptoms. Other studies show that the median duration of SARS-CoV-2 presence in feces was 22 days, which was significantly longer than in respiratory (18 days; P = .002) and serum samples (16 days; P < .001). Regardless of the infectious disease, since pathogens end up in wastewater treatment facilities, wastewater testing or wastewater-based epidemiology (WBE) may be useful in understanding the actual incidence of COVID-19 in the region. Early warning of a COVID-19 outbreak is effective.


After the Covid-19 pandemic began, countries all over the world began to monitor wastewater one after another. In Japan, the novel coronavirus was detected in wastewater for the first time in June, 2020. The CDC also officially launched the National Wastewater Surveillance System (NWSS) in September 2020. What started as a civic-based effort by academic researchers and wastewater treatment agencies has quickly become a nationwide monitoring system. The NWSS provides community-level information, specifically on COVID infections in the community, to understand which communities are experiencing rising and which are declining. The NWSS has been so successful that it allows the government to identify where infection hotspots are and deploy more resources to contain the spread.


Data from wastewater surveillance are uniquely powerful because they can capture infections in both symptomatic and asymptomatic people. And they're not affected by whether a patient has access to health care or clinical testing. These advantages can inform important public health decisions, such as where to allocate mobile testing and vaccination sites. And this system has its advantages even more for the Omicron variant, which mostly infected patients are asymptomatic. For example, on December 25 last year in Texas in the United States, through the analysis of samples collected by 35 sewage plants out of 39 in the city, it was found that the positive rate of Omicron variant increased by 164%, which also timely warned the trend of the outbreak of Omicron variant.


The U.S. NWSS system was built for COVID as part of COVID prevention, but wastewater surveillance can be applied to a wide variety of epidemic problems. The United States is now expanding wastewater surveillance platforms to collect data on other pathogens. Targets include antibiotic resistance, foodborne infectious pathogens such as E. coli, Salmonella, Norwalk influenza and emerging fungal pathogens. Japan currently does not have a surveillance system similar to NWSS, but Japan also started the " Promotion Plan for Wastewater Surveillance " in November 2021. The purpose is also to speed up the verification and analysis of wastewater surveillance, and put it into practical application as soon as possible. We look forward to its future applications.


  1. Akihiko Hata et al, June 12, 2020 “Detection of SARS-CoV-2 in wastewater in Japan by multiple molecular assays-implication for wastewater-based epidemiology (WBE)”. medRxiv

  2. Eiji Haramoto et al., published online 2020 Jun 20. “First environmental surveillance for the presence of SARS-CoV-2 RNA in wastewater and river water in Japan”. Sci Total Environ. 2020 Oct 1; 737: 140405.

  3. Yongjian Wu et al, published Online March 19, 2020 “Prolonged presence of SARS-CoV-2 viral RNA in faecal samples” Lancet Gastroenterol Hepatol. 2020 May;5(5):434-435.

  4. US Centers for Disease Control and Prevention, Newstarget,CCTV2

  5. 下水サーベイランスに関する推進計画 https://corona.go.jp/surveillance/

Regarding the information on this website (disclaimer):

The information on this website represents the best information currently available to us and is given in good faith but without warranty. We are not responsible for any loss caused by using this website. Please note that we may make changes to the information posted on this website without notice. In addition, the operation of the website may be suspended or stopped.