SARS-CoV-2 Genetic Material – COVID-19 Coronavirus – Found in Louisiana Raw Wastewater

Role of wastewater-based epidemiology in the detection of SARS-CoV-2. Credit: Masaaki Kitajima / Biorender

Group of scientists detected genetic material from SARS-CoV-2 Untreated wastewater samples collected in April 2020 from two wastewater treatment plants in Louisiana, USA.

Wastewater-based epidemiology (WBE) is a process of tracking the spread of disease in human populations by testing the wastewater. It is used to track the spread of polio and norovirus infections. Many groups around the world are working on how to develop ways to track WBE COVID-19 (New Coronavirus Infection) (# If there is no character limit, add parentheses when first appearing.. Using these methods, SARS-CoV-2 was detected in urban sewage in Australia, Spain, Italy, the Netherlands, and Japan.

Papers published in journals Total environmental science, Group of Researchers – Masaaki Kitajima with Samendra P. Sherchan of Tulane University, USA Hokkaido University – Reported detection of SARS-CoV-2 RNA An untreated wastewater sample collected in April 2020 from Southern Louisiana. This is the first report to detect a virus in North American wastewater.

Detection of SARS-CoV-2 RNA in wastewater from southern Louisiana, USA and confirmation of COVID-19 cases in two regions (WWTP A and WWTP B). Circles, squares, and triangles represent the sampling date and sampling type. Black circles indicate detection of SARS-CoV-2 in wastewater. Credit: Samendra P. Sherchan, et al. , Science of the Total Environment, June 30, 2020

Samples were collected monthly between January and April 2020 from two anonymous wastewater treatment plants, with populations of 244,627 (WWTP A) and 45,694 (WWTP B), respectively. The sample contained untreated wastewater, pre-chlorinated treated wastewater, and chlorinated wastewater. Scientists have tried to recover SARS-CoV-2 from these samples by one of two methods: ultrafiltration (filtering the sample through a very fine filter to collect virus) or adsorption elution (virus). By passing the sample through a membrane that binds to and then rinsing the virus). The amount of virus recovered was determined by reverse transcription quantitative PCR, a standard method for testing SARS-CoV-2.

Of the 15 total samples, scientists detected SARS-CoV-2 in only 2 samples. Virus was detected in the samples processed by ultrafiltration, but not in the samples concentrated by adsorptive elution. In addition, the virus was only detected in untreated waste and not in treated wastewater samples. This indicates that standard wastewater treatment can remove and/or destroy the virus. Finally, the virus was only detected in samples collected in April (WWTP A on April 29 and WWTP B on April 8). During the sampling period, the total number of confirmed cases in the area served by the wastewater treatment plant was the highest this month.

Masaaki Kitajima, Hokkaido University (left) and Samendra P. Shachan, Tulane University (right). (Photo courtesy of Masaaki Kitajima). Credit: Photo provided by Masaaki Kitajima

Scientists have concluded that ultrafiltration is an excellent method for virus recovery, but other factors may interfere with virus detection. However, further testing with a larger sample size is needed to understand the limitations of this method and compare it with other methods currently tested in the same way. In general, COVID-19 WBE requires better virus concentration and detection methods.

“A recent report on the detection of SARS-CoV-2 RNA from multiple countries, including Japan and the US, validated the WBE concept for COVID-19 surveillance,” says Masaaki Kitajima. “I hope that the COVID-19 WBE research will be accelerated globally through international cooperation.”

Assistant Professor Kitajima is currently involved in a number of studies related to applying WBE to track the epidemic of COVID-19 pandemics. In this effort, he collaborated with many scientists and research groups around the world and was part of a team that first detected SARS-CoV-2 in Japanese wastewater.

See also: “First Detection of SARS-CoV-2 RNA in North American Wastewater: A Study in Louisiana, USA” Samendra P. Sherchan, Shalina Shahin, Lauren M. Ward, Sarmila Tandukar, Tiong G. Aw, Bradley Schmitz, Warish Ahmed and Masaaki Kitajima, June 30, 2020, Science of the whole environment..
DOI: 10.1016 / j.scitotenv.2020.140621

This research is promoted by the Council (LEQSF (2018-21)-rd-a-21) and the Japan Society for the Promotion of Science (JSPS) for joint international research (Promotion of Joint International Research (B), JP18KK0270).