NEW YORK - The coronavirus originated in China in December but researchers at the Icahn School of Medicine at Mount Sinai have discovered the first cases of COVID-19 in the city came mainly from European and U.S. sources. Specifically, travelers going to and from Europe and the city.

"It was undetected so it could have transmit unrecognized in our neighborhoods," said Dr. Viviana Simon, a study researcher.

Researchers examined about 80 COVID-19 patients from 21 neighborhoods in the city. They found only one had a link to a case that originated in Asia. 

The federal government banned foreign nationals from China from entering the U.S. on January 31. The government didn’t ban travelers from most European countries until March 11.

Researchers say the virus may have been spreading in the city undetected as early as mid February. The first case in the city was identified on February 28.

"If we would have been able to identify those early cases and have people self quarantined at home we could have limited certainly narrowed down the number of cases," Simon said.

Researchers say had the city and state known this earlier, restrictions like social distancing and closing non essential businesses could have been done earlier to contain the virus. This research they say will now better prepare us for future pandemics.

"I think as a community, a scientific community we learning a lot from this as well," said Harm Van Bakel, a study researcher.

Researchers say one thing that is key for the future is developing the infrastructure for early, rapid and widespread testing.