Coronavirus cases in Italy happened earlier than previously thought, according to a new study presented Friday.
With nearly 200,000 confirmed cases of COVID-19, Italy has been atop of a global list of infections and deaths caused by the new coronavirus since the early days of the outbreak.
The first official case of a local infection was reported on Feb. 21, when a 38-year-old man checked himself into a local hospital in Codogno, a small city in Lombardy located 37 miles south of Milan.
In a matter of days, the number of infections grew exponentially. By March 19, Italy had surpassed the number of deaths registered in China, where the virus originated.
The immediate surge in infections led scientists to suspect that COVID-19 had been around before it was officially identified.
Hoping to shed light on the origins of the outbreak in Italy, researchers with the Bruno Kessler Foundation, a research center located in Trento, looked at the country’s first known cases and analyzed the pace of contagion.
“We realized that there were a lot of infected people in Lombardy well before Feb. 20, which means the epidemic had started much earlier,” Stefano Merler, a mathematical modeler of infectious diseases transmission with the foundation, said in a news conference, according to Reuters.
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“In January for sure, but maybe even before. We’ll never know,” he added.
According to Merler, the outbreak indicates that new coronavirus probably arrived in Italy via a group of people, instead of a single individual.
Coronavirus around the world: how the outbreak is affecting Europe
Another group of scientists believe that the virus may have reached Italy from Germany, and not China, in late January.
On Jan. 31, two Chinese tourists tested positive for coronavirus, while visiting the country. The couple, originally from Wuhan, arrived in Milan on Jan. 23, then traveled a couple of different cities before arriving in Rome on Jan. 28, when they later tested positive for the virus.
Italy banned air traffic to and from China on Jan. 31, but scientists say that it was already too late.