Related Experiment Video
Updated: Dec 14, 2025

Quantification and Whole Genome Characterization of SARS-CoV-2 RNA in Wastewater and Air Samples
Published on: June 30, 2023
Analysis of COVID-19 under-reporting in Brazil
Marcelo Freitas do Prado1, Bianca Brandão de Paula Antunes2, Leonardo Dos Santos Lourenço Bastos2
1Marketing e Análise, BizCapital, Rio de Janeiro, RJ, Brasil.
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.
Related Concept Videos
Bias in Epidemiological Studies
Principles of Disease Surveillance
Statistical Methods for Analyzing Epidemiological Data
Confounding in Epidemiological Studies
Prevalence and Incidence
Prevalence indicates the proportion of individuals in a population who have a specific disease or health...
Causality in Epidemiology

