Single arm study in which healthcare workers were actively invited to participate. Possible participants were asked to complete a questionnaire to determine eligibility for study entry and to identify risk factors for infection, severe infection, or adverse events associated with chloroquine use.
Volunteers who meet the eligibility requirements received chloroquine 150mg base at days 0, 15, 30, 45, 60, 75. Cumulative incidence and incidence rate of COVID-19 at days 30,60 and 90 were calculated. Presence of Immunoglobulin G (IgG) antibodies against SARS-Cov-2 was evaluated at the beginning, at the end and at any moment if they become infected with this virus.
In addition, patients were asked to complete a survey evaluating adverse effects and COVID-19 symptoms at day 0 and weeks 2,4,6,8,10, and 12.