SARS-CoV-2 Seroprevalence and Associated Factors in Manaus, Brazil: Baseline Results from the DETECTCoV-19 Cohort Study
57 Pages Posted: 4 Mar 2021 Last revised: 9 Mar 2021
Date Written: February 26, 2021
Background: Manaus located in the Brazilian rainforest has twice experienced a health system collapse due to the SARS-CoV-2 pandemic. However, little is known about which groups among the general population have been more affected.
Methods: A convenience sampling strategy via online advertising recruited 3046 adults. Sociodemographic characteristics, COVID-19-related symptoms, COVID-19 testing, self-medication and prescribed medications were recorded. Serum anti-SARS-CoV-2 nucleocapsid IgG antibodies were measured with an ELISA. 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 a maximum seroprevalence of 41.53% corrected by test characteristics and an antibody decay rate of 27%. Regression models demonstrated a strong association towards marginalized low-income and vulnerable residents with limited health access. Presence of a COVID-19 case (PR 1.39, 1.24-1.57) or death (PR 2.14, 1.74-2.62) in a household increased greatly the risk of other household members acquiring infection. SARS-CoV-2 seroprevalence was higher among those who self-medicated to prevent infection (PR 1.36, 1.27-1.46).
Conclusions: A disproportionate social and 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.
Note: Funding Statement: Ministry of Education (MEC), Brazil.
Declaration of Interests: The authors declare no conflict of interest.
Ethics Approval Statement: The research ethics committee of Federal University of Amazonas (UFAM) approved this study (CAAE:34906920.4.0000.5020) in accordance with Brazilian law
Keywords: Epidemiology, SARS-CoV-2, Manaus, Amazon, Brazil, Risk Factors, Seroprevalence, COVID-19
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