Photo by Martin Brechtl on Unsplash

What if we could detect an outbreak a week before testing shows it, using minimal effort and something readily available? If something smells fishy, it’s not fish; it’s poo.

Case counts climb at light-speed, and once we realize the virus is spreading, it can take weeks to bend the curve via distancing measures. Getting a seven-day lead on the virus means we can act to stop the silent spread, the thing that has troubled containment efforts from the beginning.

Where the influenza virus may incubate for 24-48 hours, a person could share the coronavirus for over a week before feeling sick, if that person ever feels sick at all. The virus appears in stool samples regardless of whether someone has symptoms.

  1. For the data to show an outbreak, there has to be widespread testing.
  2. For testing to reflect rapid spread, people must seek testing.
  3. People must feel ill before they seek testing, but many infected people have no symptoms.

The disease remains silent in many people, meaning we miss or underestimate how many people the virus has infected and we realize late.

Around 250 million Americans already send their waste to one of 16,000 American treatment plants. This information has literally been flushed down the toilet. The dispatched waste (sewage) travels to a central location where—to put it delicately—the solids separate from the liquid into sludge. Scientists described it as a “well-mixed” sample.

Checking sludge for rapid upticks in the virus’s concentration may give real-time evidence. A May 22, 2020 study speculated this colonic canary could be the “leading indicator of outbreak dynamics within a community.” The original study examined the sewage from a Connecticut town of 200,000.

Peccia et al., 2020

The red line shows viral concentration. The grey represents confirmed COVID-19 cases. The virus showed up in the sewage a full week before testing revealed climbing case counts.

Screening sewage could reveal a more accurate picture of infection rates where testing has been scarce. This stinky solution offers an affordable way to keep tabs on the real-time movement of the virus. It could work for wealthy and poor nations alike.

In the words of the questionable fictional doctors J.D. and Turk: “Everything comes down to poo.”

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The study referenced above is SARS-CoV-2 RNA concentrations in primary municipal sewage sludge as a leading indicator of COVID-19 outbreak dynamics by Jordan Peccia, Alessandro Zulli, Doug E. Brackney, Nathan D. Grubaugh, Edward H. Kaplan, Arnau Casanovas-Massana, Albert I. Ko, Amyn A. Malik, Dennis Wang, Mike Wang, Daniel M. Weinberger, Saad B. Omer, a preprint study. This article has not yet been peer-reviewed.

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