People infected with COVID-19 often shed the virus in their feces. Sewage pools of local wastewater can therefore allow scientists to monitor the prevalence of SARS-CoV-2 in an entire community. While detecting virus particles in highly variable water samples is a challenge, monitoring wastewater can offer extensive data about a large population where comparable levels of individualized testing might not be feasible.
Led by civil and environmental engineering professor Kara Nelson, scientists at UC Berkeley have created a lab in conjunction with wastewater utilities and public health agencies to monitor for the virus. The COVID Wastewater Epidemiology for the Bay Area Project (COVID-WEB) includes Plant & Microbial Biology graduate students Alex Crits-Christoph and Basem Al-Shayeb, as well as Energy & Resources Group alumna Sasha Harris-Lovett, who now serves as the external relations specialist of the Berkeley Water Center.
Upon the request of professor Nelson last spring, Harris-Lovett developed COVID-WEB as a steering committee of public health officials, wastewater professionals, and researchers. Harris-Lovett facilitates committee meetings used to discuss logistics, strategically plan sampling locations and frequencies, and determine ways to integrate results into public health responses. As the lab continues to analyze 30 samples each week, public health officials are able to use the data to keep track of outbreaks in neighborhoods where people may not be able to access tests and health care.
"Having a regional wastewater monitoring system is like having a fire lookout on a mountaintop,” says Harris-Lovett. “We want to be able to see smoke and marshall resources to put out the fire before it becomes an inferno."
Bioinformatics tools developed in Environmental Science, Policy, and Management professor Jill Banfield’s lab at the Innovative Genomics Institute (IGI) have also helped COVID-WEB sequence the RNA of individual SARS-CoV-2 virus strains. Crits-Christoph and Al-Shayeb have aided this work, by completing computational analyses of sequencing data and testing different methods of virus RNA discovery, respectively.
"Testing millions of individuals per day for coronavirus is a logistically daunting and financially prohibitive task, but the amazing thing about studying wastewater is that with a single sample, you can effectively test thousands of households in a community for genotypes of multiple infectious diseases," says Al-Shayeb, a graduate student in the Banfield lab. "The implications extend well beyond this pandemic."
Comparing the sequences found in the wastewater with those found through nasal swabs, the team found additional strains that had not yet been observed in California. Recognizing individual strains of COVID-19 will help improve test accuracy as the virus continues to mutate.
—This article was adapted from a Berkeley News article.