Clustering of Covid-19 infections among healthcare workers: Experience from a tertiary care center in Saudi Arabia

INTRODUCTION: Coronavirus infectious disease 2019 (COVID-19) had a significant impact on healthcare workers (HCWs) worldwide. Understanding the dynamics of infection transmission is important to develop strategies to prevent its spread. METHODS: A retrospective study of a cohort of HCWs with COVID-19 from a single tertiary care hospital during the first wave of the pandemic. Epidemiological investigations and identification of clusters of infection were done prospectively. RESULTS: A total of 326 HCWs had COVID-19 based on positive polymerase chain reaction tests for SARS-CoV-2. Ten clusters of infection were identified; nine clusters had HCWs as the index cases while one cluster had a patient as the index case. The largest cluster involved 15 transmissions, and one cluster included a secondary transmission. Sharing accommodation and social gatherings were the commonest epidemiological links. The majority of infected HCWs had mild infections, 23 (6%) required hospital admission and 3 (1%) required intensive care; all fully recovered. Majority of infections (80%) were community-acquired. Living in shared accommodation was associated with COVID-19 (120/690 versus 206/1610, P value = .01) while working in COVID-19 designated wards/units was not associated with COVID-19 (52/297 vs 274/2003, P value = .13). CONCLUSIONS: Clustering of COVID-19 was common among HCWs and related to shared accommodation and social gatherings, infection was of mild severity, and was not associated with caring for COVID-19 patients.