Characterizing COVID-19 transmission risk factors among frontline health-care workers using the WHO risk assessment tool: insights from a tertiary care center in South India

Abstract

Abstract Background The objective of this study was to assess the exposure risk factors for transmission of and subsequent infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19) among the frontline health-care workers (HCWs) in a South Indian tertiary care center during the COVID-19 pandemic. Methods This retrospective, observational study was conducted over a period of 6 months, from June 2020 to November 2020. Participants included HCWs who completed a risk assessment to identify encounters with COVID-19-positive individuals using a modified World Health Organization COVID-19 risk assessment tool. Results A total of 4744 HCWs who had exposure to COVID-19-positive individuals were assessed during the study period. There were 942 (19.8%) participants identified as having had high-risk exposure and 3802 (80.2%) identified as having had low-risk exposure. There were 106 (2.2%) participants who became infected with COVID-19 during the surveillance period of 14 days; 4.8% of high risk and 1.5% of low risk tested positive. Among the HCWs working in high-risk COVID-19 areas, only one HCW had contracted the illness (N = 1, 0.9%). Shared spaces (70%) and infection protection and control breaches (66%) were found to be highly prevalent modes of exposure in the COVID-19-positive cohort. The attack rate among COVID-19 cluster groups (two or more confirmed or probable cases of COVID-19 who are linked by the same location of exposure) (5.5%) was higher than the attack rate (2.2%) noted among the total contacts screened, and no significant association was observed between risk categories in the clustered groups. Conclusion This study highlights higher risk of COVID-19 positivity among high-risk contacts as compared to low-risk contacts.