JUL 29, 2021 7:00 AM PDT

Sewage Sleuths: Tracking COVID Variants in Wastewater

WRITTEN BY: Tara Fernandes

Since the dawn of the pandemic, one of the biggest challenges has been monitoring the crowned enemy as it spread through communities. Relying solely on diagnostic reports from hospitals and health care facilities for public health tracing isn’t ideal. There’s usually a lag time before these data are shared, plus those with mild or asymptomatic COVID-19 may not even end up getting tested. 

To bypass these hurdles, scientists have identified a valuable source of infection data: sewage. Analyzing wastewater for trace amounts of SARS-CoV-2 genetic material can help track trends in infection rates over time and pinpoint at-risk populations rapidly, all in a non-intrusive manner.

Now, an international team of scientists and data experts has come up with an inexpensive, open-source molecular detection method for measuring the B.1.1.7 (or Alpha) coronavirus variant in wastewater.

Despite the clear benefits of integrating wastewater surveillance into public health monitoring initiatives to control the spread of COVID-19, existing technologies to perform these tests aren’t optimal. For one, the technique has traditionally relied upon next-generation sequencing (NGS), a platform that is expensive to run and time-consuming. Moreover, because of the sensitivity thresholds of this technique, NGS is not suitable for detecting minute amounts of variant DNA in diluted sewage samples.

The newly-developed protocol uses RT-qPCR, a much more accessible platform for most health organizations and research institutes interested in wastewater surveillance. Validation of the innovative new tracing platform demonstrated how it could pick up variant proportions as low as 1 percent in a sample containing mixed SARS-CoV-2 strains.

The method has already been deployed to keep local health authorities in the US informed on the emergence of Alpha variant infections among their local communities. Future iterations of the monitoring platform will be adapted to detect other variants of the coronavirus.


Source: Environ. Sci. Technol. Lett.


About the Author
Doctorate (PhD)
Interested in health technology and innovation.
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