COVID-19 Contact Tracing Outcomes in Washington State, August and October 2020

Abstract

Introduction: Case investigation and contact tracing are important tools to limit the spread of SARS-CoV-2, particularly when implemented efficiently. Our objective was to evaluate participation in and timeliness of COVID-19 contact tracing and whether these measures changed over time.Methods: We retrospectively assessed COVID-19 case investigation and contact tracing surveillance data from the Washington State centralized program for August 1–31, 2020 and October 1–31, 2020. We combined SARS-CoV-2 testing reports with contact tracing data to compare completeness, reporting of contacts, and program timeliness.Results: For August and October respectively, 4,600 (of 12,521) and 2,166 (of 16,269) individuals with COVID-19 were referred to the state program for case investigation. Investigators called 100% of referred individuals; 65% (August) and 76% (October) were interviewed. Of individuals interviewed, 33% reported contacts in August and 45% in October, with only mild variation by age, sex, race/ethnicity, and urbanicity. In August, 992 individuals with COVID-19 reported a total of 2,584 contacts (mean, 2.6), and in October, 739 individuals reported 2,218 contacts (mean, 3.0). Among contacts, 86% and 78% participated in interviews for August and October. The median time elapsed from specimen collection to contact interview was 4 days in August and 3 days in October, and from symptom onset to contact interview was 7 days in August and 6 days in October.Conclusions: While contact tracing improved with time, the proportion of individuals disclosing contacts remained below 50% and differed minimally by demographic characteristics. The longest time interval occurred between symptom onset and test result notification. Improving elicitation of contacts and timeliness of contact tracing may further decrease SARS-CoV-2 transmission.

COVID-19 contact tracing during first delta wave, Lebanon, 2021

“…In similar analysis, in the USA, in June-July 2020, 57% of cases were interviewed, 1.15 was the median of contacts per case (28). The percentage of cases sharing lists of contacts ranged from 27% in Jun-Jul 2020 up to 45% in Oct 2020, and the average of contacts per case reached 2.6 to 3 in Washington State (29, 30). In USA Connecticut, the percentage of contacts notifiers reached 28% (31).…”

Addressing External Shock in Urban Agglomeration: Implications From the Transmission Pattern of COVID-19 in the Beijing-Tianjin-Hebei Area

“…The epidemic will then spread within the individual contact network. Thus, contact tracing is the most effective approach to reducing transmission risk ( 21 , 40 ), which is still implemented in China. To maximize the contact network boundary, the first step is to interview the infectors and publish information on their movement, and the micro individual approach should be adopted to identify the infected cases.…”

The United States public health services failure to control the coronavirus epidemic

“…“HHS Agencies Offices.” Text. HHS.gov, October 27, 2015 , Berg et al, 2022 , Bonacci et al, 2021 , “Case Surveillance History and Modernization | CDC,” July 11, 2022 , CDC. “Cases, Data, and Surveillance.” Centers for Disease Control and Prevention, February 11, 2020 , CDC, 2022 , CDC, 2020 , ———.…”