Wastewater surveillance to infer COVID-19 transmission: A systematic review

Wastewater Surveillance for SARS-CoV-2 RNA in Canada

Wastewater surveillance for SARS-CoV-2 RNA is a relatively recent adaptation of long-standing wastewater surveillance for infectious and other harmful agents. Individuals infected with COVID-19 were found to shed SARS-CoV-2 in their faeces. Researchers around the world confirmed that SARS-CoV-2 RNA fragments could be detected and quantified in community wastewater. Canadian academic researchers, largely as volunteer initiatives, reported proof-of-concept by April 2020. National collaboration was initially facilitated by the Canadian Water Network.

Many public health officials were initially skeptical about actionable information being provided by wastewater surveillance even though experience has shown that public health surveillance for a pandemic has no single, perfect approach. Rather, different approaches provide different insights, each with its own strengths and limitations. Public health science must triangulate among different forms of evidence to maximize understanding of what is happening or may be expected. Well-conceived, resourced, and implemented wastewater-based platforms can provide a cost-effective approach to support other conventional lines of evidence. Sustaining wastewater monitoring platforms for future surveillance of other disease targets and health states is a challenge. Canada can benefit from taking lessons learned from the COVID-19 pandemic to develop forward-looking interpretive frameworks and capacity to implement, adapt, and expand such public health surveillance capabilities.

Surveillance of SARS-CoV-2 in Sewage Treatment Plants between January 2020 and July 2021 in Taiwan

An outbreak of a new type of coronavirus pneumonia (COVID-19) began in Wuhan, Hubei Province, China, at the end of 2019, and it later spread to other areas of China and around the world. Taiwan reported the first confirmed case from an individual who returned from Wuhan, China, in January 2020 for Chinese New Year. Monitoring microbes in environmental sewage is an important epidemiological indicator, especially for pathogens that can be shed in feces such as poliovirus. We have conducted additional SARS-CoV-2 sewage testing since January 2020 using a well-established poliovirus environmental sewage surveillance system in Taiwan. Wastewater samples were collected from 11 sewage treatment plants from different parts of Taiwan twice a month for laboratory testing. By the end of July 2021, 397 wastewater specimens had been tested, and two samples were positive for SARS-CoV-2. These two wastewater samples were collected in the northern region of Taiwan from Taipei (site A) and New Taipei City (site C) at the beginning of June 2021. This result is consistent with the significant increase in confirmed COVID-19 cases observed in the same period of time. As the pandemic ebbed after June, the wastewater samples in these areas also tested negative for SARS-CoV-2 in July 2021.