Analysis of an outbreak of nosocomial COVID-19 at a tertiary care centre in South India

Background Nosocomial outbreaks of COVID-19 have been reported sporadically since the beginning of the COVID-19 pandemic. We sought to study the transmission dynamics in a nosocomial COVID-19 outbreak in our centre. Methods This was a retrospective cohort study in a 500 bedded tertiary care hospital in South India. Inpatients who were suspected to have likely or definite hospital-acquired COVID-19 and hospital staff members who were found to be COVID-19 positive during the same time frame were studied and the likely transmission dynamics described. Results During the study period, 173 patients were diagnosed to have COVID-19, out of which, 15 (8.6%) patients who fulfilled the criteria for likely or definitely hospital-acquired COVID-19 infection were identified from six different wards. During the same period, 121 hospital staff members were diagnosed with COVID-19. Out of these, 18 (14.9%) hospital staff members were identified who could have been the potential source of infection for these 15 patients based on the overlap of location of the staff and the patients, and their infectivity windows. Direct contact and fomite transmission were likely the predominant driver of transmission in our study as there was use of universal face masks and face shields. Conclusion Despite the admission of a large number of COVID-19 patients and a relatively large proportion of hospital staff members who tested positive for the disease, the proportion of nosocomial COVID-19 in our centre remained low. A policy of universal gloving, coupled with the already existing practice of universal N95 masking and face shield use, could potentially bring down the rate of nosocomial COVID-19 even further.