Remarkable Variability in SARS-CoV-2 Antibodies across Brazilian Regions: Report on Two Successive Nationwide Serological Household Surveys

24 Pages Posted: 13 Jul 2020

See all articles by Pedro C Hallal

Pedro C Hallal

Federal University of Pelotas (UFPel)

Fernando P Hartwig

Federal University of Pelotas (UFPel)

Bernardo Lessa Horta

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Mariangela F. Silveira

Pan American Health Organization, Women and Reproductive Health, CLAP SMR PAHO/WHO Latin American Center of Perinatology ; Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Claudio J Struchiner

Federal University of Pelotas (UFPel)

Luís Paulo Vidaleti

Federal University of Pelotas (UFPel)

Nelson Arns Neumann

Pastorate of the Child

Lúcia C Pellanda

Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA)

Odir A Dellagostin

Federal University of Pelotas (UFPel)

Marcelo N Burattini

Federal University of São Paulo (UNIFESP)

Ana M. B. Menezes

Federal University of Pelotas (UFPel)

Fernando C. Barros

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Aluisio J D Barros

Federal University of Pelotas (UFPel)

Cesar G. Victora

Federal University of Pelotas (UFPel) - International Center for Equity in Health (ICEH); Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Date Written: June 23, 2020

Abstract

Background: Population based data on COVID-19 are essential for guiding public policies. There are few such studies, particularly from low or middle-income countries. Brazil is currently a hotspot for COVID-19 globally.

Methods: We report on two waves of seroprevalence surveys relying upon on household probabilistic samples of 133 large sentinel cities in all Brazilian states, including 25,025 participants in the first wave (May 14-21) and 31,165 in the second wave (June 4-7). Presence of antibodies against SARS-CoV-2 was assessed using a lateral flow point-of-care test. Seroprevalence estimates were adjusted for test’s sensitivity and specificity.

Results: For the 83 cities with sample sizes of 200 or more tests in both phases, the pooled seroprevalence increased from 1.9% (95% CI 1.7%;2.1%) to 3.1% (2.8%;3.4%) over the 3-week period. City-level prevalence ranged from 0.0% to 25.4% in both phases. Eleven of the 16 cities with prevalence above 2.0% in the first wave were located in a stretch along the Amazon river in the Northern region; in the second wave, there were 34 cities with prevalence above 2%, which included the same 11 Amazon cities as well as 14 from the Northeast region, where prevalence is increasing rapidly. Prevalence levels were markedly lower in the South and Centre-West regions, and intermediate in the Southeast, where the highest level was found in Rio de Janeiro at 7.5% (4.2%;12.2%) in the second wave. In the second round, prevalence was similar in men and women, but higher levels were observed for subjects aged 20-59 years, and for those living in crowded conditions. Indigenous people had prevalence levels 6.4% (4.1%;9,4%) compared to 1.4% (1.2%;1.7%) among whites. Prevalence in the poorest socioeconomic quintile was 3.7% (3.2%;4.3%) compared to 1.7% (1.4%;2.2%) in the wealthiest quintile.

Interpretation: Our results suggest that pandemic is highly heterogenous, with rapid escalation in Brazil’s North and Northeast, and slow progression in the South and Center-West regions. Prevalence is strongly associated with indigenous ancestry and low socioeconomic position.

Note: Funding: The study was funded by the Brazilian Ministry of Health, Instituto Serrapilheira, Brazilian Collective Health Association (ABRASCO) and the JBS S.A. initiative ‘Fazer o Bem Faz Bem’.

Ethical Approval: Ethical approval was obtained from the Brazilian’s National Ethics Committee (process number CAAE 193 30721520.7.1001.5313), with written informed consent from all participants.

Declaration of Interest: None to declare

Keywords: COVID-19, SARS-CoV-2, seroprevalence surveys, Brazil, socioeconomic factors

Suggested Citation

Hallal, Pedro C and Hartwig, Fernando P and Lessa Horta, Bernardo and Silveira, Mariangela F. and Struchiner, Claudio J and Vidaleti, Luís Paulo and Arns Neumann, Nelson and Pellanda, Lúcia C and Dellagostin, Odir A and Burattini, Marcelo N and Menezes, Ana M. B. and Barros, Fernando C. and Barros, Aluisio J D and Victora, Cesar G., Remarkable Variability in SARS-CoV-2 Antibodies across Brazilian Regions: Report on Two Successive Nationwide Serological Household Surveys (June 23, 2020). Available at SSRN: https://ssrn.com/abstract=3640428 or http://dx.doi.org/10.2139/ssrn.3640428

Pedro C Hallal

Federal University of Pelotas (UFPel)

Pelotas, Rio Grande do Sul, RS
Brazil

Fernando P Hartwig

Federal University of Pelotas (UFPel)

Pelotas, Rio Grande do Sul, RS
Brazil

Bernardo Lessa Horta

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology ( email )

Rua Marechal Deodoro, 1160 - 3° Piso
Pelotas
Brazil

Mariangela F. Silveira

Pan American Health Organization, Women and Reproductive Health, CLAP SMR PAHO/WHO Latin American Center of Perinatology

Uruguay

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Brazil

Claudio J Struchiner

Federal University of Pelotas (UFPel)

Pelotas, Rio Grande do Sul, RS
Brazil

Luís Paulo Vidaleti

Federal University of Pelotas (UFPel)

Pelotas, Rio Grande do Sul, RS
Brazil

Nelson Arns Neumann

Pastorate of the Child

Brazil

Lúcia C Pellanda

Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA)

Brazil

Odir A Dellagostin

Federal University of Pelotas (UFPel)

Pelotas, Rio Grande do Sul, RS
Brazil

Marcelo N Burattini

Federal University of São Paulo (UNIFESP)

Rua Sena Madureira, 1500 - 5º andar
Vila Clementino
São Paulo, Sao Paulo 04021001
Brazil

Ana M. B. Menezes

Federal University of Pelotas (UFPel)

Pelotas, Rio Grande do Sul, RS
Brazil

Fernando C. Barros

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Rua Marechal Deodoro, 1160 - 3° Piso
Pelotas
Brazil

Aluisio J D Barros

Federal University of Pelotas (UFPel)

Pelotas, Rio Grande do Sul, RS
Brazil

Cesar G. Victora (Contact Author)

Federal University of Pelotas (UFPel) - International Center for Equity in Health (ICEH) ( email )

Brazil

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology ( email )

Brazil

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