Impact of contact tracing on COVID-19 mortality: an impact evaluation using surveillance data from Colombia
Author(s)
Vecino-Ortiz, Andres I
Villanueva Congote, Juliana
Zapata Bedoya, Silvana
Cucunuba, Zulma M
Type
Journal Article
Abstract
BACKGROUND: Contact tracing is a crucial part of the public health surveillance toolkit. However, it is labor-intensive and costly to carry it out. Some countries have faced challenges implementing contact tracing, and no impact evaluations using empirical data have assessed its impact on COVID-19 mortality. This study assesses the impact of contact tracing in a middle-income country, providing data to support the expansion and optimization of contact tracing strategies to improve infection control. METHODS: We obtained publicly available data on all confirmed COVID-19 cases in Colombia between March 2 and June 16, 2020. (N = 54,931 cases over 135 days of observation). As suggested by WHO guidelines, we proxied contact tracing performance as the proportion of cases identified through contact tracing out of all cases identified. We calculated the daily proportion of cases identified through contact tracing across 37 geographical units (32 departments and five districts). Further, we used a sequential log-log fixed-effects model to estimate the 21-days, 28-days, 42-days, and 56-days lagged impact of the proportion of cases identified through contact tracing on daily COVID-19 mortality. Both the proportion of cases identified through contact tracing and the daily number of COVID-19 deaths are smoothed using 7-day moving averages. Models control for the prevalence of active cases, second-degree polynomials, and mobility indices. Robustness checks to include supply-side variables were performed. RESULTS: We found that a 10 percent increase in the proportion of cases identified through contact tracing is related to COVID-19 mortality reductions between 0.8% and 3.4%. Our models explain between 47%-70% of the variance in mortality. Results are robust to changes of specification and inclusion of supply-side variables. CONCLUSION: Contact tracing is instrumental in containing infectious diseases. Its prioritization as a surveillance strategy will substantially impact reducing deaths while minimizing the impact on the fragile economic systems of lower and middle-income countries. This study provides lessons for other LMIC.
Date Issued
2021-03-04
Date Acceptance
2021-01-31
Citation
PLoS One, 2021, 16 (3)
ISSN
1932-6203
Publisher
Public Library of Science (PLoS)
Journal / Book Title
PLoS One
Volume
16
Issue
3
Copyright Statement
© 2021 Vecino-Ortiz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
License URL
Sponsor
Medical Research Council (MRC)
Medical Research Council (MRC)
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/33661926
PII: PONE-D-20-22545
Grant Number
MR/R024855/1
EP/V520354/1
Subjects
COVID-19
Colombia
Contact Tracing
Disease Outbreaks
Humans
Public Health Surveillance
SARS-CoV-2
Publication Status
Published
Coverage Spatial
United States
Article Number
ARTN e0246987