News Release

Less COVID-19 transmission seen in countries with more intense testing

Peer-Reviewed Publication

Health Affairs

Lacking vaccines, countries have relied on multiple non-pharmaceutical interventions to control COVID-19 transmission. Despite the urging of the World Health Organization (WHO) in March to "test, test, and test," policy makers disagree on on how much testing is optimal. A new study, by Ravindra Prasan Rannan-Eliya and coauthors from the Institute for Health Policy in Colombo, Sri Lanka, uses data from multiple online sources to quantify testing impact on COVID-19 transmissibility in 173 countries and territories (accounting for 99 percent of the world's cases) between March and June 2020. The authors found that among interventions, testing intensity had the greatest influence: a tenfold increase in the ratio of tests to new cases reported reduced average COVID-19 transmission by 9 percent. The authors note that this helps explain why countries such as China, Australia, and New Zealand achieved near elimination of COVID-19 and why lockdowns and other interventions failed to slow spread of the virus in others, such as India and Peru. "Even the wealthiest countries, such as the US, UK, and Qatar, cannot expand testing and tracing fast enough to achieve epidemic control," the authors conclude. "Early and continuous aggressive testing to keep incidence within capacity to test, trace and isolate may be the best implementation of flattening the curve."


Health Affairs is the leading peer-reviewed journal at the intersection of health, health care, and policy. Published monthly by Project HOPE, the journal is available in print and online. Late-breaking content is also found through, Health Affairs Today, and Health Affairs Sunday Update.

Visit Health Affairs' COVID-19 resource center for peer-reviewed articles, published within two weeks of submission, as well as Health Affairs Blog's COVID-19 content.

Health Affairs now has a new podcast series, A Health Podyssey, hosted by Editor-In-Chief Alan Weil, where conversations go beyond the pages of Health Affairs to tell stories behind the research and share policy implications as we journey to the intersection of health, health care, and policy.

Project HOPE is a global health and humanitarian relief organization that places power in the hands of local health care workers to save lives across the globe. Project HOPE has published Health Affairs since 1981.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.