Identifying COVID-19 Cases and Social Groups at High Risk of Transmission: A Strategy to Reduce Community Spread

As of December 2020, the coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continued throughout the United States. The initial COVID-19 pandemic response in most areas focused on mitigation measures—stay at home, social distancing, hand hygiene, face coverings, and limitations on indoor gatherings. However, starting in early summer 2020, many states relaxed some mitigation restrictions and reopened various businesses and other sectors of society. At the same time, many states began implementing a containment strategy of testing, case investigation, contact tracing, and isolation or quarantine. Routine community-based case investigation and contact tracing are usually successful in limiting transmission by isolating infected people and quarantining named contacts. Occasionally, however, people infected with SARS-CoV-2 may interact with many other people at group events, resulting in considerable undetected transmission. Little information or guidance is available to assist community-based contact-tracing programs in developing strategies and interventions to address these group exposure events. In this commentary, we propose a containment strategy that emphasizes the identification of cases at high risk of transmitting the virus to others through their interactions in social gathering groups.