COVID-19 in Brazil: Historical cases, disease milestones, and estimated outbreak peak

To the Editor,

The Coronavirus Disease 2019 (COVID-19) pandemic emerged in Sao Paulo, the largest Brazilian city, on Feb 26 [1], when a 61 years-old man presented Severe Acute Respiratory Syndrome, after returning from Turin, Italy. Until March 7, the Brazilian Ministry of Health (BMH) reported 19 cases: 11 cases in people coming from Italy, 3 from Italy and another country (German, Spain, and Australia), 3 from other countries (USA, UK, and Iran), and 2 cases of local transmissition (associated with the first case). On March 13 (98 cases), the first cases of community transmission of Sars-CoV-2 occurred in Sao Paulo and Rio de Janeiro cities, the two main Brazilian COVID-19 epicenters. Confirmed cases continued to grow fast in a classical exponential curve (r² = 0.95), with a rapid rate per day (~25%), similarly to those initially observed in other European countries, including Italy, Spain, and France [2]. On April 15, 28,320 patients tested positive, and 1,736 deaths were reported (~6.1% mortality).

Brazilian authorities made several fast and emergency decisions to reduce the velocity of the fast-growing number of infected people in the country and the number of casualties. For instance, in the Sao Paulo State, the main COVID-19 Brazilian epicenter, the timeline of the positive cases and the emergency decisions [3] are summaryzed in Fig. 1 . According to the previous reports [2,4], these decisions purpose to protect elderly patients and people with comorbidities, to promote social distancing for avoiding fast Sars-CoV-2 dissemination, and c) to improve the health services related to the pandemic COVID-19.

Fig. 1.

Timeline of the COVID-19 cases and emergency decisions made in Sao Paulo State, Brazil. Source: Brazilian Ministry of Health and Government of the Sao Paulo State.

After 3 weeks of quarantine exclusion, it is clear that governmental decisions in the Sao Paulo State have significant effect on pandemic COVID-19 growing; average of increasing was 9.1% in the last week against 26.1% in the week before quarantine exclusion. However, it is still early to have precise conclusions and further emergency decisions can be required to reduce the COVID-19 growing spread. The Imperial College London [5] estimated the COVID-19 impact in several countries, including Brazil, according to different strategies for social distancing. Based on this report, specifically for the State of Sao Paulo (~46 million people, ~21.7% of the Brazilian population), considering early suppression and a transmissibility index (R₀) of 3, by the end of the pandemic, we can find the following estimates: infected people = 2,475,090; individuals requiring hospitalisation = 54,047; patients requiring critical care = 12,0405; and total of deaths = 9,551. Because health system has a limited capacity to attend all COVID-19 patients, it is important to flatten the pandemic COVID-19 curve to avoid the system overload. Assuming different effectiveness of the emergency decisions imposed by the government in reducing the growing spread of the Sars-CoV-2 by 25, 50, or 75% (E₂₅, E₅₀, and E₇₅, respectively), we were able to calculate the peak of pandemic COVID-19 in Sao Paulo State (when 50% of the infected people will be reached, that is 1,237,545). For E₂₅, E₅₀, and E₇₅, the outbreak peak will occur on May 18–19, June 3–4, and July 20–21, respectively. The next days will be crucial to evaluate the effectiveness of the emergency decisions and to held and to direct important and further emergency decisions to avoid the fast advance of the pandemic COVID-19 and the health system collapse.

Funding source

Authors acknowledge grants from FAPESP, CAPES, and CNPq.

Declaration of competing interest

All authors declare no conflict of interest.