Slow Spread of SARS-CoV-2 in Southern Brazil Over a 6-Month Period: Report on 8 Sequential Statewide Serological Surveys Including 35 611 Participants

Abstract

Objectives. To evaluate the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) over 6 months in the Brazilian State of Rio Grande do Sul (population 11.3 million), based on 8 serological surveys. Methods. In each survey, 4151 participants in round 1 and 4460 participants in round 2 were randomly sampled from all state regions. We assessed presence of antibodies against SARS-CoV-2 using a validated lateral flow point-of-care test; we adjusted figures for the time-dependent decay of antibodies. Results. The SARS-CoV-2 antibody prevalence increased from 0.03% (95% confidence interval [CI] = 0.00%, 0.34%; 1 in every 3333 individuals) in mid-April to 1.89% (95% CI = 1.36%, 2.54%; 1 in every 53 individuals) in early September. Prevalence was similar across gender and skin color categories. Older adults were less likely to be infected than younger participants. The proportion of the population who reported leaving home daily increased from 21.4% (95% CI = 20.2%, 22.7%) to 33.2% (95% CI = 31.8%, 34.5%). Conclusions. SARS-CoV-2 infection increased slowly during the first 6 months in the state, differently from what was observed in other Brazilian regions. Future survey rounds will continue to document the spread of the pandemic. (Am J Public Health. Published online ahead of print June 29, 2021: e1–e9. https://doi.org/10.2105/AJPH.2021.306351 )

Estimating the early impact of vaccination against COVID-19 on deaths among elderly people in Brazil: Analyses of routinely-collected data on vaccine coverage and mortality

“…The decline in mortality was observed for both sexes. Proportionate mortality at older ages was higher among women than for men, which is compatible with higher case-fatality of younger male adults, possibly related to comorbidities, given that existing serological surveys do not suggest differences in infection prevalence by sex [21,22]. The reductions in proportionate mortality were very similar across four of the five regions of the country.…”

Population-level seropositivity trend for SARS-Cov-2 in Rio Grande do Sul, Brazil

“…Our study, to our knowledge, is the longest series of surveys carried out on the same population, covering 10 rounds over 13 months of the COVID-19 pandemic. Earlier results for phases 1-8 were published elsewhere 10 . At the time of the early rounds of the study, the only rapid test available in large amounts in the country was the Wondfo lateral-flow test, which had been imported by a Brazilian mining conglomerate and donated to the Ministry of Health.…”

“…Intending on monitoring the population level of seropositivity we started the EPICOVID19-RS study in April 2020 and by September we had conducted eight rounds of the study. Seroprevalence was estimated by using the Wondfo rapid test, increasing from 0.03% in round 1 to 1.89% in round 8 10 . With time, we noticed that the test's sensitivity could not be as high as we initially believed and that it decreased over time 11 .…”

“Te cuida”

“…Entretanto, ele apenas sugere tal mudança, mesmo à beira do colapso do sistema de saúde estatal. Hallal et al (2021Hallal et al ( , p. 1548 coloca "A pressão dos empresários e do governo federal para reabrir a economia; [...] O governo passou a liberar a apelação das cidades contra as cores determinadas pelo modelo para a sua região como alguns dos motivos para os pontos positivos do combate à pandemia no começo da crise terem sido perdidos no decorrer do ano de 2020".…”