Alliance for Pandemic Preparedness

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Tag: contact tracing

June 4, 2021

COVID-19 Case Investigation and Contact Tracing in the US, 2020

A cross-sectional study of contact tracing programs in 13 US health departments and 1 Indian Health Service Unit across 11 states found that 2 out of 3 individuals with SARS-CoV-2 infection (N=74,185) were either not reached for interview or named no contacts when interviewed. A mean of 0.7 contacts per case were reached by telephone…

May 5, 2021

Effect of Manual and Digital Contact Tracing on COVID-19 Outbreaks: A Study on Empirical Contact Data

A model assessing the impact of contact tracing on epidemic size reduction suggests that for manual contact tracing, as the fraction of contacts correctly recalled increases there are linear reductions in epidemic size while reductions were quadratically reduced with digital contact tracing via apps, as both case and contact need to be running the app….

April 9, 2021

Notes from the Field : COVID-19 Case Investigation and Contact Tracing Program — Spirit Lake Tribe, North Dakota, September–November 2020

In September 2020, a CDC-assisted, tribally managed COVID-19 case investigation and contact tracing program for the Spirit Lake Tribe in North Dakota was implemented in response to increasing incidence of COVID-19. Between September 29 and November 20, 2020, 317 persons with confirmed COVID-19 and 667 close contacts were reported. 80% of patients with confirmed COVID-19…

March 29, 2021

Stochastic Sampling Effects Favor Manual over Digital Contact Tracing

A study using a stochastic model to compare manual and digital contact tracing methods found that even if the probability of tracing a contact was equal by each method, manual tracing robustly performed better than digital, after accounting for intrinsic delays and limited scalability associated with manual measures. The authors note that better performance of…

January 22, 2021

COVID-19 Case Investigation and Contact Tracing Efforts from Health Departments — United States, June 25–July 24, 2020

An analysis of case investigation and contact tracing metric data reported by 56 U.S. health departments found wide variation in capacity and ability to conduct timely and effective contact tracing. A median of 57% of COVID-19 patients were interviewed within 24 hours of report of the case to a health department; a median of 1.2…

January 12, 2021

Bidirectional Contact Tracing Could Dramatically Improve COVID-19 Control

A modeling study found that bi-directional contact tracing could double the reduction in effective reproductive number (Reff) compared to conventional forward-tracing alone. Bi-directional contact tracing identifies potential infectors of known cases, which could lead to identification of additional cases arising from the potential infectors. The authors also suggest expanding the tracing window from 2-6 days…

November 9, 2020

Effectiveness of Contact Tracing and Quarantine on Reducing COVID-19 Transmission: A Retrospective Cohort Study

A cohort study among COVID-19 patients in Portugal (n=551) from March 1 to April 30, 2020 found no significant difference in the attack rate from index cases between patients who received contact tracing, isolated and had close contacts who were quarantined and those who did not (12%, 95% CI 7–19% vs. 9%, 95% CI 8–11%,…

August 20, 2020

Automated and Partly Automated Contact Tracing: A Systematic Review to Inform the Control of COVID-19

• A systematic review of 15 studies published from Jan 1 to April 30, 2020 reported no empirical epidemiological evidence regarding the effectiveness of automated contact tracing tools, in contrast to manual contract tracing, for identifying contacts or reducing transmission of respiratory viral infections. Four modelling studies estimated that controlling COVID-19 requires a high population…