DOI: 10.5061/dryad.dz08kps08
title: Data from: SARS-CoV-2 antibody dynamics in blood donors and COVID-19 epidemiology in eight Brazilian state capitals

description: The COVID-19 situation in Brazil is complex due to large differences in
 the shape and size of regional epidemics. Here we tested monthly blood
 donation samples for IgG antibodies from March 2020 to March 2021 in eight
 of Brazil’s most populous cities. The inferred attack rate of SARS-CoV-2
 adjusted for seroreversion in December 2020, before the Gamma VOC was
 dominant, ranged from 19.3% (95% CrI 17.5% - 21.2%) in Curitiba to 75.0%
 (95% CrI 70.8% - 80.3%) in Manaus. Seroprevalence was consistently smaller
 in women and donors older than 55 years. The age-specific infection
 fatality rate (IFR) differed between cities and consistently increased
 with age. The infection hospitalisation rate (IHR) increased significantly
 during the Gamma-dominated second wave in Manaus, suggesting increased
 morbidity of the Gamma VOC compared to previous variants circulating in
 Manaus. The higher disease penetrance associated with the health system’s
 collapse increased the overall IFR by a minimum factor of 2.91 (95% CrI
 2.43 – 3.53). These results highlight the utility of blood donor
 serosurveillance to track epidemic maturity and demonstrate demographic
 and spatial heterogeneity in SARS-CoV-2 spread.
description: We tested 97,950 blood donation samples for anti-SARS-CoV-2 IgG
 antibodies using the anti-N Abbott chemiluminescent microparticle
 immunoassay (CIMA). Tests were performed from March 2020 to March 2021 in
 eight Brazilian capitals: São Paulo, Manaus, Belo Horizonte, Curitiba,
 Fortaleza, Recife, Rio de Janeiro.<br><br>We also tested blood
 samples from convalescent plasma donors to estimate the sensitivity of the
 assay. To estimate test specificity, we tested blood donation samples from
 São Paulo collected in February 2020, before the beginning of the
 SARS-CoV-2 epidemic in Brazil. In order to estimate the
 time-to-seroreversion distribution (used to correct for antibody waning),
 we also tested samples from repeat blood donors.<br><br>Please
 see "Methods" section in the manuscript for more detailed
 information on this dataset.
description: This repository contains four datasets:<br><br>1)
 Bloodbank.csv: The longitudinal cohort containing the tested blood samples
 used to estimate the seroprevalence in the eight cities.<br>2)
 repeat_blood_donors.csv: The cohort of repeat blood donors used to
 estimate the probability distribution of the
 time-to-seroreversion.<br>3)
 convalescent_plasma_longitudinal_roche.csv: Convalescent plasma donors
 used to estimate the sensitivity of the assay.<br>4)
 prepandemic_cohort.csv: The pre-pandemic blood donors cohort, containing
 samples tested in February 2020 in São Paulo.<br><br>In all
 files, each row represents a tested blood sample. Information as exact
 age, education level and declared race were removed to ensure data are
 anonymized. For the same reason, dates of sample collection were
 substituted by the corresponding week numbers, and the date of onset was
 substituted by the time interval between the date of sample collection and
 the date of onset in the convalescent plasma donors dataset.
 <br><br>See data_dictionary.pdf for the data
 dictionary.