The study “Pre-exposure Hydroxychloroquine use is associated with reduced COVID19 risk in healthcare workers, by Bhattacharya and collaborators, found efficacy in pre-exposure prophylaxis for medical workers. Prof. Bhattacharya is with the Department of General Medicine at the Medical College of Kolkata in India.
To be noted here is that this study is about pre-exposure prophylaxis, and not the much less solid “post-exposure prophylaxis” concept recently studied by a US / Canada randomized questionable research.
106 health care workers were included in the study, 54 of which received hydroxychloroquine as prophylaxis. The two groups were comparable in terms of age, gender, comorbidities and exposure.
The health care workers were exposed to COVID-19 patients at a care center where there was “an abrupt cluster outbreak within on duty personnel.”
PCR testing was used to find out if COVID-19 positivity.
Among the 54 workers having taken HCQ as a prophylaxis, 4 were found positive. Among the 52 who did not take HCQ, 20 were found positive.
“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, compared to those who were not on it, X2=14.59, p<0.001. None of the HCQ users noted any serious adverse effects.”
“This study demonstrated that voluntary HCQ consumption as pre-exposure prophylaxis by HCWs is associated with a statistically significant reduction in risk of SARSCoV-2.”
See pre-print at: https://www.medrxiv.org/content/10.1101/2020.06.09.20116806v1