1893. Risk Categorization and Outcomes among Healthcare Workers Exposed to COVID-19: A Cohort Study from A Thai Tertiary-care Center

Abstract

Abstract Background A risk categorization tool for healthcare workers (HCWs) exposed to severe acute respiratory syndrome coronavirus-2 is crucial for preventing coronavirus disease 2019 (COVID-19) transmission and requires validation and modification according to local context. We conducted this study to evaluate the performance of the study risk categorization tool and COVID-19-related outcomes among HCWs. Methods From 1 January to 31 December 2021, a prospective cohort study was conducted among COVID-19 exposing HCWs at a Thai tertiary-care center. The study risk categorization tool was specifically created in this study and modified from the United States Centers for Disease Control and Prevention recommendations, which classified HCWs into low-risk (LR), intermediate-risk (IR), and high-risk (HR) groups based on types of activities, duration of exposure, and protective methods used during exposure. Subsequent measures were determined for the HCWs based on the risk categories. The primary outcome was the difference in rates of COVID-19 in the LR, IR and HR HCWs. Results There were 1,892 HCWs included; 52%, 25% and 23% were LR, IR, and HR, respectively. The median age was 30 years (IQR, 26-36 years). The majority was female (79%) and nurses (33%). The most common risk activities were being in the same room with closed space without wearing a mask with COVID-19 cases (75%). COVID-19 was diagnosed in 157 HCWs and 27%, 5% and 1% of HR, IR and LR HCWs, respectively (P< 0.001). By multivariable analysis, factors associated with COVID-19 included household or community exposure [adjusted odds ratio (aOR), 1588.68; P< 0.001], being HR group (aOR, 11.94; P< 0.001), working at outpatient departments (aOR, 2.54; P< 0.001), and no history of COVID-19 vaccination (aOR, 2.05; P=0.01). The monthly rates of COVID-19 among LR, IR, and HR HCWs significantly decreased after the incremental rate of full vaccination. In-hospital transmission between HCWs occurred in 8% and was mainly due to eating at the same table (58%). Conclusion The study risk categorization tool can differentiate risks of COVID-19 among the HCWs. Prevention of COVID-19 should be focused on HCWs with the identified risk factors and behaviors associated with COVID-19 development and encouraging receipt of full vaccination. Disclosures All Authors: No reported disclosures.