PT  - JOURNAL ARTICLE
AU  - Andrea Ramírez Varela
AU  - Sandra Contreras-Arrieta
AU  - Guillermo Tamayo-Cabeza
AU  - Leonardo Salas Zapata
AU  - Yuldor Caballero-Díaz
AU  - Luis Jorge Hernández Florez
AU  - Andrés Patiño Benavidez
AU  - Rachid Laajaj
AU  - Fernando De la Hoz
AU  - Giancarlo Buitrago Gutierrez
AU  - Silvia Restrepo
AU  - Eduardo Behrentz
ED  - ,
TI  - Risk factors for SARS-CoV-2 transmission in close contacts of adults at high risk of infection due to occupation: results from the contact tracing strategy of the CoVIDA epidemiological surveillance study in Bogotá, Colombia, in 2020–2021
AID  - 10.1136/bmjopen-2022-062487
DP  - 2022 Dec 01
TA  - BMJ Open
PG  - e062487
VI  - 12
IP  - 12
4099  - http://bmjopen.bmj.com/content/12/12/e062487.short
4100  - http://bmjopen.bmj.com/content/12/12/e062487.full
SO  - BMJ Open2022 Dec 01; 12
AB  - Objectives To estimate the risk factors for SARS-CoV-2 transmission in close contacts of adults at high risk of infection due to occupation, participants of the CoVIDA study, in Bogotá D.C., Colombia.Setting The CoVIDA study was the largest COVID-19 intensified sentinel epidemiological surveillance study in Colombia thus far, performing over 60 000 RT-PCR tests for SARS-CoV-2 infection. The study implemented a contact tracing strategy (via telephone call) to support traditional surveillance actions performed by the local health authority.Participants Close contacts of participants from the CoVIDA study.Primary and secondary outcome measures SARS-CoV-2 testing results were obtained (RT-PCR with CoVIDA or self-reported results). The secondary attack rate (SAR) was calculated using contacts and primary cases features.Results The CoVIDA study performed 1257 contact tracing procedures on primary cases. A total of 5551 close contacts were identified and 1050 secondary cases (21.1%) were found. The highest SAR was found in close contacts: (1) who were spouses (SAR=32.7%; 95% CI 29.1% to 36.4%), (2) of informally employed or unemployed primary cases (SAR=29.1%; 95% CI 25.5% to 32.8%), (3) of symptomatic primary cases (SAR of 25.9%; 95% CI 24.0% to 27.9%) and (4) living in households with more than three people (SAR=22.2%; 95% CI 20.7% to 23.8%). The spouses (OR 3.85; 95% CI 2.60 to 5.70), relatives (OR 1.89; 95% CI 1.33 to 2.70) and close contacts of a symptomatic primary case (OR 1.48; 95% CI 1.24 to 1.77) had an increased risk of being secondary cases compared with non-relatives and close contacts of an asymptomatic index case, respectively.Conclusions Contact tracing strategies must focus on households with socioeconomic vulnerabilities to guarantee isolation and testing to stop the spread of the disease.Deidentified participant data and data dictionaries will be shared by formal request to the corresponding author.