Dec 3, 2020 - Health

Study: Increased COVID-19 testing can reduce transmission

picture of a health professional wearing PPE taking a nasal swab sample from a patient
Photo: Faris Hadziq/SOPA Images/LightRocket via Getty Images

Increasing the number of coronavirus tests performed relative to a country's caseload was the strategy most associated with reducing the transmission rate of the virus, according to a new study published in Health Affairs.

Yes, but: The U.S. overall had a low testing intensity between March and June, which means that "testing mostly diagnosed and isolated the most symptomatic cases, which has limited impact on transmission."

  • Even though we're now doing more than a million tests a day, it's not enough to keep up with our ever-rising caseloads.

Details: A tenfold increase in the ratio of tests to new cases reduced average transmission by 9%, the study found.

Between the lines: "Around half or more of COVID-19 transmission is caused by people who are asymptomatic or who have only minor symptoms, so only increases in PCR testing make it possible to increase detection and isolation of infectious cases, and then to increase the numbers of their potentially infectious contacts who are isolated," the authors write.

  • "This remains the only known approach that blocks person-to-person transmission sufficiently to stop the epidemic."

Bonus: The study also found that "being a US territory was also significantly associated with a 12.7% ... increase in transmissibility compared to the rest of the world."

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