Chemistry trio reunite in new literature review highlighting the efficacy of wastewater-based epidemiology to track and mitigate the spread of COVID-19

by Sam Kealhofer, Intern on the A&S Research Support Team

To provide relevant data on the occurrence, persistence, analysis and disinfection of COVID-19 in water and wastewater systems, as well as to guide future research and policy decisions, Mississippi State University Department of Chemistry faculty members Charles Pittman, Todd Mlsna, and Dinesh Mohan collaborated on a new literature review, “Coronavirus (SARS-CoV-2) in the Environment: Occurrence, Persistence, Analysis in Aquatic Systems and Possible Management,” which is in press with Science of the Total Environment, a peer-reviewed journal.

The review investigates the viral shedding in fecal matter and urine, explaining the impacts this contamination can have on connected aquatic systems. The researchers said SARS-CoV-2 genomes have been discovered in wastewaters, sewage sludge and river waters around the world, which creates concerns about the potential environmental spread of COVID-19 through water and soil.

The review explains that, historically, viral diseases in water and wastewater can cause community-level transmission, which poses particular risk to hospitals and healthcare buildings, as well as to developing countries where sewage runs directly into surface waters where downstream it is used for drinking or bathing. Viruses also can spread within or between buildings when they enter water and wastewater systems. The review estimates that contaminated water sources can deliver the equivalent of about 100 infectious doses with 100 mL of water or less in countries with high infections.

SARS coronaviruses can survive up to four days in stool samples and up to several weeks in sewage and water, according to the MSU researchers, who said the contaminated waterways can lead to more infections by contaminating surface waters or other vectors.

The researchers said common disinfectants like bleach, ethanol, sodium hypochlorite and hand soap solution can be used to disinfect contaminated wastewater. The researchers also highlight remediation efforts discussed in their previous work on pharmaceutical pollution like oxidation, filtration, radiation and adsorption and the contribution they could make in wastewater disinfection.

The review stresses the science of wastewater-based epidemiology (WBE), or wastewater surveillance, to combat the virus. The MSU team said several studies have demonstrated that SARS-CoV-2 monitoring of the wastewater flow into a treatment plant allows the observation of RNA fragments from the entire catchment basin of that plant on a daily basis. This could provide an early indication of the number of COVID-19 cases in a community.

Because viral shedding starts before the detection of COVID-19 infections, as in asymptomatic and presymptomatic cases, SARS-CoV-2 monitoring in sewage sludge, which is both concentrated and a well-mixed sample, could become an early indicator of an outbreak in a given community. The researchers said this method could prove much more accurate than current strategies because they do not have a way to track asymptomatic and presymptomatic individuals, who account for about 18-31% of those infected.

The researchers said the science is relatively inexpensive and many countries already have systems capable of analyzing waste. The science was used by Barcelona, Spain, during the onset of the pandemic to predict viral RNA in wastewater 41 days before the first case was reported, validating WBE as an asset for pandemic surveillance.

Pittman, Mlsna, and Mohan once again find themselves on the forefront of research, investigating some of the most pressing issues of the moment. Their innovative and collaborative spirits enable them to apply their wealth of knowledge in crucial ways, suggesting avenues of research critical to informing future viral tracking methods.

In an effort to contribute solutions to the various challenges facing the nation, as well as insight into other points of interest, the College of Arts & Sciences will continue to highlight faculty research in our “Research in the Headlines” series each Monday and Wednesday. For more research in the headlines, visit https://www.cas.msstate.edu/research/researchintheheadlines/; and for information about the College of Arts & Sciences or the Department of Chemistry visit https://www.cas.msstate.edu/ or https://www.chemistry.msstate.edu/.