Pre exposure hydroxychloroquine prophylaxis for covid-19 in healthcare workers: a retrospective cohort

ABSTRACT BACKGROUND OF STUDY While several trials are ongoing for treatment of COVID-19, scientific research on chemoprophylaxis is still lacking even though it has potential to flatten the curve allowing us time to complete research on vaccines. OBJECTIVES OF THE STUDY To explore the potential of HCQ as a pre-exposure prophylaxis for COVID 19 in health care workers in a tertiary care hospital. MATERIALS & METHODS We have conducted a retrospective cohort study among 106 Health Care Workers (HCW) exposed to COVID-19 patients, at a tertiary care hospital in India where there was an abrupt cluster outbreak within on duty personnel. HCWs who had voluntarily taken hydroxychloroquine (HCQ) prior to exposure were considered one cohort while those who had not were considered to be the Control group. All participants with a verifiable high risk contact history were tested for COVID-19 by RT-PCR. RESULTS The two cohorts were comparable in terms of age, gender, co-morbidities and exposure. The primary outcome was incidence rates of RT-PCR positive COVID-19 infection amongst HCQ users and Controls. In this retrospective cohort study, 106 healthcare workers were examined of whom 54 were HCQ users and rest were not. The comparative analysis of incidence of infection between the two groups demonstrated that voluntary HCQ usage was associated with lesser likelihood of developing SARS-CoV-2 infection (4 out of 54 HCW), compared to those who were not on it (20 out of 52 HCW), χ2 =14.59, p CONCLUSIONS This study demonstrated that voluntary HCQ consumption as pre-exposure prophylaxis by HCWs is associated with a statistically significant reduction in risk of SARS-CoV-2. These promising findings therefore highlight the need to examine this association in greater detail among a larger sample using Randomised Controlled Trials (RCT).