Epidemiology of COVID-19 in two cities in southern Brazil: a cross-sectional population-based study

The first recommendations to prevent coronavirus disease 2019 (COVID-19) were made without epidemiological information on what would be people’s behaviors in view of the biopsychosocial and physical effects of confinement because of a health emergency with great economic impact. Objective: To determine the incidence of COVID-19; analyze the associated behavioral and sociodemographic factors. Methods: Cross-sectional population-based study with a representative sample of two cities in southern Brazil. 2,170 individuals aged 18 years or over were interviewed from October 2020 to January 2021. Data were collected in person at the place of residence of the individuals using a questionnaire.  Results: The incidence of COVID-19 was 6.8% (95% confidence interval, CI: 5.4; 8.4), and was significantly higher in white people, aged between 18 and 59 years, married, with higher education, higher family income, and who lived in an apartment. The incidence of COVID-19 was associated with diabetes. People who stayed less time at home has a higher incidence (3.7% versus 7.5%). The most reported symptoms were excessive tiredness, reduced smell and taste. Most of the individuals (85%) sought a health facility and less than 5% were hospitalized. Conclusion: Almost one in ten individuals was infected by COVID-19. The incidence was higher for adults (because of being more exposed), individuals from higher socioeconomic level (because of having tested more) and in diabetics. Almost everyone stayed home after being diagnosed with the virus, and the main risk factor was having contact with someone infected.