In this letter to the editor, the authors aim to predict the total number of COVID-19 cases and deaths in Brazil by January 2021.
As of August 19, 2020, Brazil has already had more than 300 million COVID-19 cases. The number of deaths is past 100,000 with a case fatality rate of 3.2%. Case fatality rate is the percentage of patients that pass away due to a disease compared to the total number of cases. The case fatality rate is likely an underestimate because researchers cannot keep track of all of the asymptomatic cases. Brazil is also hardly hit due to high urban density, economic pressures, and insufficient testing. Social distancing restrictions were lifted early to relieve some of the economic burden.
Slums in Brazil are particularly vulnerable to infection. People live closely together with less facilities. Due to social disparities, the people do not have the same access to healthcare. Many cannot afford to socially distance and instead go to work. Past epidemics indicate slums have some of the higher transmission rates.
As of January 2021, the three models predicted a different total number of cases and deaths in Brazil. The researchers averaged the three models. They predict Brazil will have 5 million total cases and 161,212 deaths. The actual predictions from each model can be found in the paper.
The models did not account for possible waning immunity, vaccination, or other possible health factors. Another limitation is that the models do not account for the political effect and mistrust due to the pandemic.
The researchers suggest that models can be created based on the amount of social distancing. If there is no social distancing, there could be up to 28 million cases and 902,787 deaths in Brazil by January 2021. Regardless, Brazil has already suffered a lot because of this pandemic. Social distancing is essential to prevent the large loss of life.
The authors of the paper use three open-source models: Delphi, Squire, and YYG. The models are susceptible-infected-exposed-recovered (SEIR) models. They were used to predict the number of cases at a certain time. The models also predicted the number of deaths based on the case fatality rate.