Testing at scale during the COVID-19 pandemic

Assembly and publication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome in January 2020 enabled the immediate development of tests to detect the new virus. This began the largest global testing programme in history, in which hundreds of millions of individuals have been tested to date. The unprecedented scale of testing has driven innovation in the strategies, technologies and concepts that govern testing in public health. This Review describes the changing role of testing during the COVID-19 pandemic, including the use of genomic surveillance to track SARS-CoV-2 transmission around the world, the use of contact tracing to contain disease outbreaks and testing for the presence of the virus circulating in the environment. Despite these efforts, widespread community transmission has become entrenched in many countries and has required the testing of populations to identify and isolate infected individuals, many of whom are asymptomatic. The diagnostic and epidemiological principles that underpin such population-scale testing are also considered, as are the high-throughput and point-of-care technologies that make testing feasible on a massive scale. Population-scale testing is an essential component of responses to the COVID-19 pandemic and is likely to become increasingly important in public health. Here, Mercer and Salit describe the roles of testing during the COVID-19 pandemic, including in genomic surveillance, contact tracing and environmental testing.

Automated summary

The assembly and publication of the SARS-CoV-2 genome in January 2020 allowed for immediate development of tests and led to the largest global testing programme in history. Despite efforts to control the spread, widespread community transmission of the virus has become entrenched in many countries, necessitating population-scale testing to identify and isolate infected individuals. Testing plays a crucial role in the response to the COVID-19 pandemic and is likely to continue to be vital in public health.