The impact of super-spreader cities, highways, and the availability of intensive care units in the early stages of the COVID-19 epidemic in Brazil

Source: Nicolelis, MAL et al. 2021.Scientific Reports,

São Paulo, Brazil – A multidisciplinary analysis by a group of Brazilian scientists published online in the journal Scientific reports on June 21, 2021 revealed that three main factors were responsible for the geographic spread of SARS-COV-2 in Brazil, as well as the massive influx of people looking for hospital care across the country during the first wave of the pandemic in Brazil were 2020. SARS-CoV-2 reached Brazil via the country’s international airports at the end of February 2020. The mathematical modeling showed that in the first weeks of March 2020, the “super-spreader city” São Paulo, which is located next to the largest Brazilian international airport and the busiest motorway junction in the country, more than 85% of the COVID- The fall of 19 spread all over Brazil. Taking into account just 16 other cities of spread, the authors were able to spot 98-99% of the cases reported during the first 3 months of the Brazilian pandemic in 2020. Most of this spread of COVID-19 cases resulted from people using the country’s major highways and airspace, which remained open throughout the month of March 2020. For example, a group of 26 major federal highways alone accounted for around 30% of the cases of SARS-CoV-2 that were widespread during this period.

After community transmission emerged in the 16 major superspreaders, SARS-CoV-2 cases spread to the Brazilian countryside via the country’s federal and state highways. As cases increased exponentially in the Brazilian interior, critically ill patients had to be transported from the interior of the country to state capitals for access to intensive care beds, creating a “boomerang effect” that helped slow the spread of COVID-19 – Distort deaths. Therefore, the distribution of COVID-19 deaths began to correlate with the distribution of the country’s highly uneven distribution of intensive care units (ICUs), which is heavily weighted across state capitals.

According to one of the study’s authors, Miguel Nicolelis, “Our analysis clearly showed that if national roadblocks and mandatory road traffic restrictions were enforced in major Brazilian super-spreader cities, particularly the city of São Paulo, the impact of COVID-19 in Brazil would be significantly lower during the first wave, but also during the even more damaging second wave that hit the country a year later in the summer of 2021. From June 2020 to June 2021, Brazil rose from 50,000 to 500,000 deaths. a tenfold increase within 12 months. This alone illustrates the total failure of the Brazilian federal government to protect Brazilians from the worst humanitarian tragedy in the entire history of the country. ”

In Brazil, the vast majority of tertiary hospitals, and therefore the largest proportion of ICU beds, are located in major cities that serve as state capitals, their metropolitan areas, and a handful of medium-sized cities inland in each state. As a result of the “boomerang effect” widespread across the country, Brazil experienced the largest increase in hospital admissions in its history, leading to a peak in deaths in any of the cities with a large number of intensive care units. Such a “boomerang flow” was not limited to streets and highways. In the Amazon rainforest in the northern region of Brazil, for example, seriously ill COVID-19 patients from many small communities on the riverbank were transported by boats of all kinds across its major rivers towards the two largest Amazon cities, Manaus and Belém. Overall, analysis of the geographic flow of COVID-19 patients revealed that São Paulo, the largest Brazilian super-spreader city, received patients from 464 different cities across Brazil, followed by Belo Horizonte (351 cities), Salvador (332 cities ), Goiânia (258 cities), Recife (255 cities) and Teresina (225 cities). São Paulo was also the city that sent more residents to other cities (158 cities), followed by Rio de Janeiro (73 cities), Guarulhos (41 cities), Curitiba (40 cities), Campinas (39 cities), Belém (38 Cities) and Brasilia (35 cities). Overall, cities that were heavily connected to the health system, either by taking in or sending patients to other cities, also had higher numbers of COVID-19 deaths. Because of the “boomerang effect”, a significant number of seriously ill patients had to migrate to larger cities for treatment and eventually died there. Combined with the deaths of residents in major cities, the widespread “boomerang effect” contributed significantly to the geographic bias of the COVID-19 death distribution across Brazil.

Commenting on the results of the study, Rafael Raimundo, another author, said that “Our analysis shed light on the mechanisms by which COVID-19 spread rapidly across Brazil. Our results also suggest that if non-pharmacological measures such as highway and roadblocks had been enforced early on at the national or even regional level, thousands of lives could have been saved at the start of the COVID-19 pandemic in Brazil.

The authors also emphasized the fundamental importance of the Brazilian public health system, known as SUS, in their conclusions. Rafael Raimundo says, “Without the SUS public health infrastructure that has been built over the past 40 years, the effects of COVID-19 would certainly be even more devastating. However, our data also show that the high magnitude of the ‘boomerang effect’ underscores the need for SUS to install more hospital infrastructure, including more intensive care beds, in the Brazilian interior to better support and care for the rural population. ”

“The widespread lack of adequate hospital infrastructure and medical professionals in the Brazilian countryside has certainly contributed significantly to a high number of deaths that could have been avoided altogether. However, what if the Brazilian federal government had responded quickly and correctly to the arrival of SARS-CoV-2 by setting up a national scientific task force to combat the pandemic while running and closing a national communication campaign to warn the population? of the country’s airspace, while Brazil imposed a national lockdown in early March 2020, including the construction of roadblocks on major federal and state highways, Brazil would almost certainly have avoided the loss of tens of thousands of lives, ”added Miguel Nicolelis.


The authors of this article were: Miguel AL Nicolelis, Department of Neurobiology, Duke University Medical Center, Durham, NC, USA, and Edmond and Lily Safra International Institute of Neurosciences, Natal, Brazil, Rafael LG Raimundo, Department of Engineering and Environment and Postgraduate Program in Ecology and Environmental Monitoring (PPGEMA), Center for Applied Science and Education, Universidade Federal da Paraíba – Campus IV, Rio Tinto, Paraíba, Brazil, Pedro S. Peixoto, Institute of Applied Mathematics, Institute of Mathematics and Statistics, University of São Paulo , São Paulo, Brazil, and Cecilia S. Andreazzi, Laboratory of Biology and Parasitology of Wild Reservoir Mammals, IOC, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil. The mobility data used in this study comes from a collaboration between the Department of Applied Mathematics, Institute of Mathematics and Statistics, University of São Paulo, and the company InLoco / Incognia.

Item link:

https: //doi.Organization/10.1038 /s41598-021-92263-3


Please enter your comment!
Please enter your name here