Recent data has shown that the spread of coronavirus in New York began in about mid-February, which is weeks before the first confirmed case. Studies of COVID-19 cases in New York indicate it was spread mainly by people who were traveling from Europe and not Asia. A geneticist at Icahn School of Medicine at Mount Sinai named Harm van Bakel co-wrote a study (awaiting peer review) about the genome of New York coronavirus cases, saying, “The majority is clearly European.” After studying an entirely different group of cases, a separate team at N.Y.U. Grossman School of Medicine arrived at noticeably similar conclusions.
In order to track viral mutations, scientists must sequence all the genetic material in a virus, known as its genome. When the genomes from a number of virus samples have been gathered, mutations between the genomes can be compared. Because mutations arise at a roughly regular pace, they act as a molecular clock, and intricate computer programs are able to figure out how those mutations arose as viruses descended from a common ancestor. If enough data is sampled, researchers can make rough estimates about how long ago those ancestors lived.
Each team conducted tests and analyzed genomes from coronaviruses taken from New Yorkers beginning in mid-March. The research demonstrated that a previously hidden spread of Sars-Cov-2 (coronavirus) could have been detected if proactive testing programs had begun earlier than they did.
President Trump put in place a policy to stop foreign nationals (who had been in China for two weeks prior) from entering the country on January 31st. However, it was not until late February that Italy began to lock down their towns and cities, and it was not until March 11th that Mr. Trump said he would prohibit and block travelers from most European countries. The main problem then became that New Yorkers had already been traveling home with the virus and spreading it in the city.