Very high rates of Covid-19 in the Brazilian Amazon

By testing approximately 1,000 blood donation samples each month in in the Brazilian cities of São Paulo and Manaus, an international team of researchers have shown that, while both cities have experienced large epidemics with high mortality, as much as three-quarters of the population in Manaus was infected between March and October, and a third of the population in São Paulo. Researchers from the University of São Paulo (USP, São Paulo, Brazil), the Fundação Hospitalar de Hematologia e Hemoterapia do Amazonas (Hemoam, Manaus, Brazil), Fundação Pró-Sangue/Hemocentro de São Paulo, Imperial College London, and the University of Oxford United Kingdom, worked together to collect and analyze data on the prevalence of SARS-CoV-2 antibodies, a marker of prior infection, among blood donors in the Brazilian cities of Manaus and São Paulo. Their research is  published . The authors state that these results are a data-based warning of what may be the extent of SARS-CoV-2 transmission in the absence of effective mitigation. Brazil has experienced an unprecedented epidemic caused by SARS-CoV-2, with >6.5 million cases reported to date and >175 thousand deaths. The Amazon region, in the north of the country, has been hardest hit. In Manaus, mortality increased rapidly in April, with overwhelmed health services requiring communal graves to bury the dead.