Hydroxychloroquine as pre-exposure prophylaxis against COVID-19 in health-care workers: A single-center experience

Background: Health-care workers (HCWs) are at high risk of acquiring COVID-19. Hydroxychloroquine (HCQ) possesses in vitro antiviral activity and inhibits viral replication of coronavirus in cell cultures. The national task force for COVID-19 in India recommended the use of HCQ prophylaxis against severe acute respiratory syndrome coronavirus 2 infection in HCWs. Methodology: We conducted a retrospective cohort study in a mixed tertiary care facility to find the incidence and clinical profile of COVID-19 in HCWs between April 2020 and June 2020, who were advised preexposure prophylaxis with HCQ, at the start of the pandemic. Details of HCQ usage were collected using an online questionnaire form. The clinical profile, treatment, and outcome of COVID-19-positive HCWs were also studied. Results: We included 604 HCWs, of which 491 (81.2%) had taken adequate HCQ prophylaxis while 113 (18.7%) did not take adequate HCQ, 443 (73.3%) had high-risk COVID-19 exposure, and 32 HCWs (5.1% of the total) were COVID-19 positive. There were 10 COVID-19 cases (2.1%) among HCWs taking HCQ while 22 (19.4%) cases occurred in HCQ not compliant HCWs, with a relative risk of 0.1046 (95% confidence interval: 0.0510-0.2147, P< 0.0001), indicating a reduced risk of COVID-19 among HCWs taking HCQ prophylaxis. Among the noncompliant cases, 14 (43.7%) never took HCQ, 4 (12.5%) took HCQ but had poor compliance, and 4 (12.5%) stopped HCQ prematurely. Most (91.7%) COVID-19-positive HCWs were asymptomatic or had mild symptoms, moderate symptoms were seen in 3 (9.3%), and there were no severe cases or deaths. Conclusions: The use of HCQ as preexposure prophylaxis in HCWs was associated with reduced risk of COVID-19, suggesting its role as an effective chemoprophylactic agent.