Seroprevalence of SARS-CoV-2 in Brazil: A systematic review and meta-analysis.

OBJECTIVES: To summarize the data on SARS-CoV-2 seroprevalence surveys conducted in Brazil before the introduction of vaccines METHODS: The authors conducted a systematic review and meta-analysis on the seroprevalence of SARS-CoV-2 infection in Brazil. The present review followed the PRISMA guidelines. The authors searched Medline, Embase, and LILACS databases for serologic surveys conducted in the Brazilian population, in the period from 01/10/2019 to 07/11/2021, without language restrictions. The authors included studies that presented data concerning SARS-CoV-2 antibodies seroprevalence in Brazil and had a sample size ≥50 individuals. Considering the expected heterogeneity between studies, all analyses were performed using the random effects model, and heterogeneity was assessed using the I2 statistic RESULTS: Of 586 publications identified in the initial searches, 54 were included in the review and meta-analysis, which contained the results of 135 surveys, with 336,620 participants. The estimated seroprevalence was 11.0%, ranging from 1.0% to 83.0%, with a substantial heterogeneity (I2 = 99.55%). In subgroup analyses, the authors observed that the prevalence of SARS-CoV-2 antibodies was 13.0% in blood donors, 9.0% in the population-based surveys, 13% in schoolchildren, and 11.0% in healthcare workers. CONCLUSIONS: Seroprevalence increases over time. Large differences were observed among the regions of the country. It was higher in the Northern region, decreasing towards the South. The present results may contribute to the analysis of the spread of SARS-CoV-2 infection in the Brazilian population before vaccination, one of the factors that may be influencing the clinical presentation of COVID-19 cases related to the new variants, as well as the effectiveness of the vaccination program.

Brazilians' level of knowledge, attitudes and practices towards COVID-19: a cross-sectional study.

BACKGROUND: Brazil is facing increasing cycles of numbers of infected people and deaths resulting from coronavirus disease 2019 (COVID-19). This situation involves a series of factors, including the behavior of the population, that can be decisive for controlling the disease. OBJECTIVE: To determine the knowledge, attitudes and practices of the Brazilian population regarding COVID-19. DESIGN AND SETTING: Cross-sectional survey-type study, conducted using a population sample from different Brazilian states. METHODS: A quantitative, descriptive and analytical approach was used. Sampling was done according to convenience and via snowballing. The data collection instrument was a knowledge, attitudes and practices system. RESULTS: 1,655 people from all over Brazil participated in the survey; 80% were living in the southern region and 70.15% were female. More than 90% had knowledge and good attitudes relating to the means of transmission, preventive care and symptoms associated with COVID-19, although their knowledge and attitudes were not fully reflected in daily practices, for which there was lower adherence (80%). Greater knowledge was correlated with older participants, larger number of children, female sex and marital status; better attitude, with female sex and complete higher education; and better practices, with greater age, larger number of children and female sex. CONCLUSION: A large part of the population has general knowledge about COVID-19, but not all knowledge was applied in practice. Older people, females and university graduates stood out as the best informed and most committed to controlling the disease.