The new coronavirus was already spreading in Brazil in early February, several weeks before the announcement of the first confirmed case, including during carnival festivities, when millions of people were celebrating on the streets, according to a study by the institute of Fiocruz reference.
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The Covid-19 "began to circulate in Brazil in the first week of February", we can read in this study published earlier this week. The first officially confirmed case, a man returning from a trip to Italy, was not announced by the Ministry of Health until February 26.
This date coincides with Ash Wednesday, which marks the end of the carnival and its gatherings of thousands of people in the streets for several days.
Find the traces of the virus
The Fiocruz study estimates that, as in Brazil, the virus began to spread several weeks before the confirmation of the first cases in other countries, such as Italy or the United States.
And in most of these countries, community-based transmission (not linked to people who have traveled to infected countries) began before measures were taken by governments to stem the pandemic.
"This long period of unidentified community transmission shows how difficult it is to find traces of the circulation of the new coronavirus," explains Gonzalo Bello, coordinator of the study. "It also shows that action must be taken sooner, at least as soon as we start to identify the first imported cases," he concludes.
More than 11,500 dead
The first Covid-19 death in Brazil was confirmed by health officials on March 17. Since then, the virus has killed more than 11,500 people, with at least 168,000 people infected, even if the official figures are largely underestimated according to specialists.
The first containment measures were taken by the governors of Rio de Janeiro and Sao Paulo in mid-March, a few days before the announcement of the first covid-19 death, but three weeks after the first confirmed case.