Methods
Searches for studies were performed in peer-reviewed and gray literature. The following elements were used to define eligibility criteria: (1) Population, individuals with laboratory-confirmed SARS-CoV-2 infection; (2) Intervention, nitazoxanide; (3) Comparison, placebo; (4) Outcomes: positive RT-PCR status, composite measure of disease progression (severe COVID-19, ICU admission or invasive mechanical ventilation), death, serum biomarkers of inflammation (C-reactive protein, IL-6, and IL-8), and any adverse events; (5) Study type: blinded, placebo-controlled, randomized clinical trials (RCT). Treatment effects were reported as relative risk (RR) and mean difference (MD) with 95% confidence intervals (CI).