Affiliation:
1. Department of Internal Medicine, Health Sciences Center, Federal University of Santa Catarina (UFSC), Florianópolis,
Brazil
Abstract
Background:
At the beginning of the coronavirus disease (COVID-19) pandemic, hydroxychloroquine
(HCQ) was widely used as a possible antiviral agent. Current knowledge indicates
that HCQ has little or no effect on individual clinical outcomes of COVID-19, but populational effects
on disease transmissibility are still unknown.
Objective:
This study investigates the hypothesis that massive HCQ consumption by a population may
contribute to reducing the transmissibility of SARS-CoV-2 and COVID-19 spread by reducing the
viral load of infected individuals.
Methods:
Public database of seven states from Brazil in 2020 were assessed, before the start of
COVID-19 vaccination. The daily values of the COVID-19 effective reproduction number (Rt) were
obtained. Associations between Rt values and the proposed predictor variables (prevalence of COVID-
19 as a marker of collective immunity; social isolation indices; consumption of HCQ) were tested using
multiple linear regression analysis.
Results:
In all seven states, consumption of HCQ was a significant negative predictor of Rt (β ranged
from -0.295 to -0.502, p = 0.001). Furthermore, the mean derivative of Rt during the declining period
of the COVID-19 incidence (the mean rate of variation) was also significantly negatively related to the
mean HCQ consumption in that period (R2 = 0.895; β = -0.783; p = 0.011), meaning that the higher the
HCQ consumption, the faster the decline of COVID-19 Rt. It suggests a dose-response phenomenon
and a causal relationship in this association.
Conclusion:
The results of this study are compatible with the hypothesis that HCQ has small but significant
in vivo antiviral effects that are able to reduce SARS-CoV-2 transmissibility at the populational
level.
Publisher
Bentham Science Publishers Ltd.
Subject
Microbiology (medical),Pharmacology,Molecular Medicine,General Medicine