October 27, 2020 | General

Testing Wastewater For COVID-19 Virus

Top: Microscopic view of the virus which causes Coronavirus disease.
Credit: NIAID, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) and the Michigan Department of Health and Human Services (MDHHS) created a $10 million grant for a three-month pilot program this fall to fund local public health department efforts to coordinate with counties, universities, and other institutions across the state on COVID-19 wastewater testing programs. Local monitoring has the potential to be an early warning system for the spread of COVID-19 within a specific community or for coronavirus outbreaks on college campuses and at other densely populated facilities. The grant funds, sourced from Michigan’s allocation of federal money under the Coronavirus Aid, Relief, and Economic Security Act (CARES), are targeting existing COVID-19 wastewater surveillance programs in the state to establish a standardized and coordinated network of monitoring systems that began operating by October 1, 2020.

Testing wastewater for viruses, such as the SARS-CoV-2 virus that causes COVID-19, can be an effective tool for monitoring transmission of COVID-19 within a local community or at individual facilities. The virus is shed in human waste, including people who are not ill or have not yet become ill. The virus can then be detected by testing samples taken from sewers and wastewater treatment plants, with results often being available earlier than human clinical samples. These results can then inform local public health actions to prevent further spread within that community. During the three-month pilot project, EGLE is coordinating sample collection, lab analysis, data reporting, and communication with the local monitoring teams across Michigan. MDHHS is providing project support to participating local health departments, including how to integrate local wastewater data with other types of COVID-19 surveillance and public health responses.

As part of the program, Michigan will leverage its existing network of laboratories involved in monitoring the state’s beaches for E. coli. These labs are equipped to test for viruses like the SARS-CoV-2 virus that causes COVID-19 and are capable of supporting local wastewater testing. Northern Michigan University (NMU) in Marquette is a case in point. NMU Biology Professor Josh Sharp and students in his lab are monitoring Marquette wastewater for COVID-19, applying the same methods they have used to test local beach water for E. coli. For both testing applications, Sharp relies on real-time Polymerase Chain Reaction (PCR), a molecular microbiology technique that amplifies targeted DNA molecules. “All PCR requires is that you have a unique gene sequence you can amplify,” Sharp explained in a recent NMU press release. “It doesn’t matter what organism it is, you can tailor PCR to detect whichever one you’re interested in. So it’s just a matter of adapting it for COVID-19.” He adds that PCR’s effectiveness was demonstrated recently in East Lansing. The technology was able to detect COVID-19 in the wastewater at Michigan State University about five days before there were reports of a spike in cases tied to a local restaurant and brew pub.

“Depending on where you sample from the sewer, you can localize it,” said Sharp. “In Marquette, we’ll take it from the wastewater treatment plant for a snapshot of the city as a whole. There’s also the potential to sample from various stations that service different areas of city, or even campus specifically.” With the state funding for the COVID monitoring project, NMU purchased a more sophisticated PCR instrument. Digital droplet PCR (ddPCR) is more sensitive than conventional PCR and allows for easier quantitation of viral levels in a specific sample, noted the press release. It will also support a research technician to help analyze multiple samples per day and train students in the procedures. “Acquiring ddPCR technology enables NMU students to participate in pathogen detection research that utilizes the most current advances in PCR technology,” noted Sharp, adding that students are seeing “public health research in action.”

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