Analysis of COVID-19 under-reporting in Brazil.

Prado, Marcelo Freitas do; Antunes, Bianca Brandão de Paula; Bastos, Leonardo Dos Santos Lourenço; Peres, Igor Tona; Silva, Amanda de Araújo Batista da; Dantas, Leila Figueiredo; Baião, Fernanda Araújo; Maçaira, Paula; Hamacher, Silvio; Bozza, Fernando Augusto; do Prado, Marcelo Freitas; Bastos, Leonardo dos Santos Lourenço; da Silva, Amanda de Araújo Batista

OBJECTIVE To estimate the reporting rates of coronavirus disease 2019 (COVID-19) cases for Brazil as a whole and states. METHODS We estimated the actual number of COVID-19 cases using the reported number of deaths in Brazil and each state, and the expected case-fatality ratio from the World Health Organization. Brazil's expected case-fatality ratio was also adjusted by the population's age pyramid. Therefore, the notification rate can be defined as the number of confirmed cases (notified by the Ministry of Health) divided by the number of expected cases (estimated from the number of deaths). RESULTS The reporting rate for COVID-19 in Brazil was estimated at 9.2% (95%CI 8.8% - 9.5%), with all the states presenting rates below 30%. São Paulo and Rio de Janeiro, the most populated states in Brazil, showed small reporting rates (8.9% and 7.2%, respectively). The highest reporting rate occurred in Roraima (31.7%) and the lowest in Paraiba (3.4%). CONCLUSION The results indicated that the reporting of confirmed cases in Brazil is much lower as compared to other countries we analyzed. Therefore, decision-makers, including the government, fail to know the actual dimension of the pandemic, which may interfere with the determination of control measures.