Building case investigation and contact tracing programs in U.S. state and local health departments: a conceptual framework

The COVID-19 pandemic and earlier health events have demonstrated that when effectively implemented, case investigation and contact tracing (CI/CT) can break chains of transmission by promptly identifying, quarantining, and monitoring the contacts of infected cases, thereby limiting further spread of a disease in a community. Many public health experts agree that implementing CI/CT at the early stages of an outbreak can be an extremely effective approach to controlling an outbreak; as such, health departments must have CI/CT capacities in place prior to the detection of an outbreak to ensure readiness to respond. At the onset of the COVID-19 pandemic, and to this day, U.S. state and local public health departments lack comprehensive CI/CT guidelines that clearly define the capabilities, capacities, outcomes, and impacts of CI/CT programs. This research has resulted in the first comprehensive analysis of the goals, capabilities, and capacities of CI/CT programs, as well as a conceptual framework that represents the relationships between these program components and considerations. Our findings highlight the need for further guidance to assist U.S. state and local public health departments in shifting CI/CT program goals as outbreaks evolve. Moreover, training the public health workforce on making decisions around CI/CT program implementation during evolving outbreaks is critical to ensure readiness to respond to a variety of outbreak scenarios.