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. 2021 Sep:110:141-150.
doi: 10.1016/j.ijid.2021.07.017. Epub 2021 Jul 14.

SARS-CoV-2 seroprevalence and associated factors in Manaus, Brazil: baseline results from the DETECTCoV-19 cohort study

Pritesh Lalwani  1 , Bárbara Batista Salgado  2 , Ivanildo Vieira Pereira Filho  3 , Danielle Severino Sena da Silva  2 , Thiago Barros do Nascimento de Morais  2 , Maele Ferreira Jordão  2 , Aguyda Rayany Cavalcante Barbosa  4 , Isabelle Bezerra Cordeiro  5 , Júlio Nino de Souza Neto  6 , Enedina Nogueira de Assunção  6 , Rafaella Oliveira Dos Santos  2 , Nani Oliveira Carvalho  2 , Wlademir Braga Salgado Sobrinho  2 , Cristiano Fernandes da Costa  7 , Pedro Elias de Souza  8 , Bernardino Claudio de Albuquerque  9 , Christian A Ganoza  10 , Roger V Araujo-Castillo  11 , Spartaco Astofi Filho  12 , Jaila Dias Borges Lalwani  13 ; DETECTCoV-19 Study Team
Affiliations

SARS-CoV-2 seroprevalence and associated factors in Manaus, Brazil: baseline results from the DETECTCoV-19 cohort study

Pritesh Lalwani et al. Int J Infect Dis. 2021 Sep.

Abstract

Background: Manaus, located in the Brazilian rainforest, has experienced two health system collapses due to the coronavirus disease 2019 (COVID-19) pandemic. However, little is known about which groups among the general population have been most affected.

Methods: A convenience sampling strategy via online advertising recruited 3046 adults between 19 August 2020 and 2 October 2020. Sociodemographic characteristics, COVID-19-related symptoms, COVID-19 testing, self-medication and prescribed medications were recorded. Serum anti-severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) nucleocapsid immunoglobulin G antibodies were measured with an enzyme-linked immunosorbent assay. Prevalence ratios (PR) were obtained using cluster-corrected and adjusted Poisson's regression models.

Results: A crude positivity rate among asymptomatic and symptomatic individuals was estimated at 29.10%, with maximum possible seroprevalence of 44.82% corrected by test characteristics and an antibody decay rate of 32.31%. Regression models demonstrated a strong association towards marginalized low-income and vulnerable residents with limited access to health care. The presence of a COVID-19 case [PR 1.39, 95% confidence interval (CI) 1.24-1.57] or death (PR 2.14, 95% CI 1.74-2.62) in a household greatly increased the risk of other household members acquiring infection. The seroprevalence of SARS-CoV-2 was higher among those who self-medicated to prevent infection (PR 1.36, 95% CI 1.27-1.46).

Conclusions: Disproportionate socio-economic disparity was observed among the study participants. The syndemic nature of COVID-19 in the Amazon region needs differential policies and urgent solutions to control the ongoing pandemic.

Keywords: Amazon; COVID-19; Epidemiology; Risk factors; SARS-CoV-2; Seroprevalence.

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Conflict of interest statement

Declaration of Competing Interest None declared.

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