Introduction
Since China began communicating deaths due to an unknown pneumonia in
late December 2019, an outbreak of a new virus identified as SARS-CoV-2
has been in course. On March 16th, the first death by
COVID-19 was reported in Brazil. Currently (July
23th), 82.890 official deaths and 2.231.871 confirmed
SARS-CoV-2 infections were reported (Worldometer, 2020). Brazil has 211
million inhabitants, corresponding to 2.7% of the world population.
However, more than 13 % of worldwide COVID-19 cases and deaths are
concentrated in Brazil. Almost half (45%) of the officially reported
COVID-19 deaths are concentrated in the southeast region of Brazil,
mainly in the states of São Paulo and Rio de Janeiro. Minas Gerais is
the largest southeast state, located in the richest Brazilian region,
with high connectivity by roads to other states and a large flux of
goods and persons. It has an extension of 586.528 km2and 21 million people on average, similar to Ukraine, France, and Spain.
Nevertheless, according to official sources, it accumulates less than
2.170 deaths (SUS, 2020). The aforementioned state plays an important
role due to its agribusiness and mining industry impacting strongly on
the national economy under a pandemic scenario, leading to cost lives
and business decrease. Test coverage is 5.45 tests per 1000 inhabitants
(considering serological and PCR tests), the second smallest among
Brazilian states (Ariadne, 2020). The social distancing percentage in
Minas Gerais dropped from about 53% in the last week of March to around
38% in the second week of July (InLoco, 2020). In a scenario of a large
population, intense human fluxes, and decrease in social distancing, the
low coverage of COVID-19 testing represents the jeopardy of such
striking underestimated deaths reported by governmental sources.
As the number of COVID-19 patients is increasing dramatically (Han et
al., 2020), it is crucial to triage and evaluate confirmed
infected/death cases. There is evidence suggesting that infected but
asymptomatic people are still able to infect others (Day, 2020) and
SARS-CoV-2 transmission from these cases has already been observed
(Rothe et al., 2020; Tong et al., 2020). Likewise, superspreading events
(SSEs), which are associated with both explosive growths early in an
outbreak and sustained transmission in later stages have been reported
(Frieden and Lee, 2020), leading to higher mortality. Simulation makes
available rapid estimation of the infections course, providing
quantification and understanding of the spatiotemporal outbreak
spreading (Siettos and Russo, 2013). In this context, correct
assessments of cases in a target population, as well as the trend of
infections/deaths provide important insights which might guide
authorities when making decisions (Nishiura et al., 2020).
Public data from the Registry Office (RO) (Cartorio, 2020) have pointed
out 1.654 excess deaths due to SARS and COVID-19 in 2020 in Minas Gerais
compared to the same period in 2019 (January 1st to
July 1st). It represents 115 % of the COVID-19
official deaths informed by the State Surveillance Service, indicating
potential excess deaths attributable to sub-notified COVID-19 deaths.
The standard approach to calculate the expected number of deaths, in the
absence of a given event of interest, uses the previous year’s
historical all-deaths data for the same timeline as baseline reference
(Nogueira et al., 2005). However, current social distancing and
isolation are not comparable with any historical mortality rate reported
so far, and therefore this approach does not reflect the expected excess
mortality presently observed. The aim of this study was to analyse and
consider other criteria for better estimating deaths, infected cases,
and high mortality due to COVID-19, comparing its geographic
distribution as well as its impact in different ethnic groups in Minas
Gerais.