We assessed the associations of social distancing and mask use with symptomatic, laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection in Porto Alegre, Brazil. We conducted a population-based case-control study during April–June 2020. Municipal authorities furnished case-patients, and controls were taken from representative household surveys. In adjusted logistic regression analyses of 271 case-patients and 1,396 controls, those reporting moderate to greatest adherence to social distancing had 59% (odds ratio [OR] 0.41, 95% CI 0.24–0.70) to 75% (OR 0.25, 95% CI 0.15–0.42) lower odds of infection. Lesser out-of-household exposure (vs. going out every day all day) reduced odds from 52% (OR 0.48, 95% CI 0.29–0.77) to 75% (OR 0.25, 95% CI 0.18–0.36). Mask use reduced odds of infection by 87% (OR 0.13, 95% CI 0.04–0.36). In conclusion, social distancing and mask use while outside the house provided major protection against symptomatic infection.
【저자키워드】 COVID-19, coronavirus disease, severe acute respiratory syndrome coronavirus 2, viruses, respiratory infections, zoonoses, SARS-CoV-2, social isolation, Masks, Social distance, Pandemics, Communicable disease control, 【초록키워드】 Brazil, coronavirus, social distancing, Infection, Mask, symptomatic, Control, Logistic regression, moderate, case-control study, symptomatic infection, association, Analysis, Odds ratio, acute respiratory syndrome, 95% CI, Porto, laboratory-confirmed, controls, conducted, provided, reduced, adjusted, odds of infection, 【제목키워드】 Brazil, coronavirus 2, Mask, respiratory,