COVID-19 Contact Tracing as an Enduringly Important Public Health Tool
Melanie M Taylor, Kimberly D. Spencer, Henry T. Walke · JAMA Health Forum · 2021
Case investigation and contact tracing are primary mitigating interventions used to control and prevent person-to-person spread of infectious diseases by identifying persons with confirmed and probable diagnoses (cases) and notifying, monitoring, and supporting the individuals who have been exposed and possibly infected (contacts).[1][2][3][4] These are routine public health activities for sexually transmitted diseases, HIV, and tuberculosis, for which treatment can be offered to contacts who are infected, thereby interrupting the chain of transmission.Rapid identification and isolation of each new case and quarantine of any contacts who are potentially infected were key interventions that effectively limited secondary transmission resulting from the importation of Ebola virus to the US in 2014.However, until the COVID-19 pandemic, contact tracing had never been needed on such a large scale in the US. DeliveryCase investigation and contact tracing succeed if persons with COVID-19 are promptly diagnosed, notified, and rapidly isolated and are willing and able to identify their close contacts during their infectious period-and if those contacts, on being notified of exposure, are willing and able to begin immediate quarantine, ideally before they themselves develop COVID-19 or transmit the causative virus (SARS-CoV-2).Even in the context of increasing cases and expanding COVID-19 vaccine availability, case investigation and contact tracing are cornerstone interventions of the US COVID-19 response.Because SARS-CoV-2 can spread through persons who are asymptomatic or presymptomatic, these public health services are most effective as part of a multifaceted response that includes other nonpharmaceutical interventions, including avoiding gatherings, universal masking, physical distancing, increasing testing, and other key mitigation strategies.2-5 Support to Health Jurisdictions The primary role of the Centers for Disease Control and Prevention (CDC) during a pandemic is to provide guidance and technical assistance to state, tribal, local, and territorial health department partners.During the COVID-19 pandemic, the CDC has also provided guidance for use by health departments to train new and existing staff in effective delivery of case investigation and contacting tracing.The CDC also encourages the use of innovative technologies to enhance these interventions, including anonymous notification of persons with exposures through smartphone applications and various digital tools to automate daily symptom monitoring.Using funds from the Coronavirus Aid, Relief, and Economic Security Act, Paycheck Protection Program, and Health Care Enhancement Act, the CDC awarded almost $11 billion to 64 state, county, and territorial jurisdictions through the Epidemiology and Laboratory Capacity for Prevention and Control of Emerging Infectious Diseases (ELC) cooperative agreement.An additional $19.1 billion has been approved through the Coronavirus Response and Relief Supplemental Appropriations Act of 2021 to continue to support state, local, and territorial health departments to build capacity around COVID-19 mitigation activities, including enhancing the ability to identify and investigate cases, conduct contact tracing, and implement containment measures.As such, the estimated number of case investigators reported by these jurisdictions increased by more than 50% (from approximately