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

Pedro C. Hallal, Mariangela F. Silveira, Ana M.B. Menezes, Bernardo L. Horta, Aluisio J.D. Barros, Lucia C. Pellanda, Gabriel D. Victora, Odir A. Dellagostin, Claudio J. Struchiner, Marcelo N. Burattini, Marilia A. Mesenburg, Nadege Jacques, Luis Paulo Vidaletti, Emanuele L. Ambros, Evelise M. Berlezi, Helena Schirmer, Jane D.P. Renner, Kaue Collares, Maria Leticia R. Ikeda, Thiago M. ArdenghiPatricia De Gasperi, Fernando P. Hartwig, Fernando C. Barros, Cesar G. Victora

Research output: Contribution to journalArticlepeer-review

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 from0.03%(95%confidence interval [CI]50.00%, 0.34%; 1 in every 3333 individuals) inmid-April to 1.89% (95% CI51.36%, 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% CI520.2%, 22.7%) to 33.2% (95% CI531.8%, 34.5%). Conclusions. SARS-CoV-2 infection increased slowly during the first 6 months in the state, differently fromwhat was observed in other Brazilian regions. Future survey rounds will continue to document the spread of the pandemic.

Original languageEnglish (US)
Pages (from-to)1542-1550
Number of pages9
JournalAmerican journal of public health
Volume111
Issue number8
DOIs
StatePublished - Aug 2021
Externally publishedYes

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health

Fingerprint

Dive into the research topics of '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'. Together they form a unique fingerprint.

Cite this