AUSTIN, Texas – Contact tracing programs were deployed around the globe to slow the spread of COVID-19, but these programs could not prevent the multiple waves of transmission and loss of life that have occurred since March 2020. In a new study published in the Proceedings of the National Academy of Sciences, researchers at The University of Texas at Austin found that a five-day delay between identifying a case and isolating contacts was the Achilles' heel of a contact tracing program in a large U.S. city.
Using a mathematical model to analyze data collected by the program between October 2020 and January 2021, the study concludes that shortening that delay from five days to a single day would prevent 26.6% more infections under certain conditions. The findings can inform cities' efforts to increase the effectiveness of contact tracing programs, including those intended to mitigate the effects of emerging threats.
