The number of confirmed cases of the U.K. variant of the coronavirus in New York has nearly doubled in a week.

The variant, known as B.1.1.7, is believed to be twice as contagious as the coronavirus strain that is prevalent worldwide. It first emerged last month in the United Kingdom and its rapid transmissibility of alarmed health officials and prompted Prime Minister Boris Johnson to implement new national lockdowns.

It has since been detected in at least 60 countries, according to the World Health Organization.

The first known case of the U.K. variant in New York was reported in Saratoga Springs on Jan. 4. Gov. Andrew Cuomo announced one case of the U.K. strain in Nassau County on Jan. 9.

By Jan. 20, when Cuomo announced the first two cases detected in Suffolk, there were 22 confirmed cases in New York State.

Today, the governor said that number of cases in N.Y. had risen to 42. He announced additional cases in Long Island, New York City, Westchester, Saratoga, Tompkins, Niagara, Onondaga, Essex and Warren Counties. He did not say how many cases have been confirmed in Suffolk and Nassau individually.

As of Monday, there were more than 350 cases of the U.K. strain confirmed in 26 U.S. states, according to the federal Centers for Disease Control and Prevention.

The actual number of cases of the U.K. variant in the U.S. — or the other two widely circulating variants first identified in South Africa and Brazil — is unknown.

The presence of the variants can be confirmed by mapping the genomes of confirmed positive coronavirus cases. The U.S. lacks the capability to conduct genome mapping on a mass scale, scientists at the National Academies of Sciences, Engineering & Medicine warned last July. Genome mapping is being done on fewer than 3,000 of the 1.4 million positive cases weekly in the U.S. The confirmed positives cases themselves are only a sampling of actual cases, since not all infected people get tested — a portion are asymptomatic or have only mild symptoms.

New York State first began genome sequencing on Dec. 23, Cuomo said today. Since then, he said, the state has done genome mapping on 2,800 confirmed positives — less than 1 percent of the 400,000 new positive cases confirmed since Dec. 23.

Complicating surveillance efforts further is the possibility that variants (mutations) of the virus can result in false negative test results, the federal Food and Drug Administration said earlier this month in a letter to clinical laboratory staff and health care providers.

As the U.K. variant becomes more prevalent, testing positivity rates may actually fall due to an increcoronasing number of false negative test results.

>>>>More COVID-19 coverage, data and updates

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Denise Civiletti
Denise is a veteran local reporter, editor, attorney and former Riverhead Town councilwoman. Her work has been recognized with numerous awards, including investigative reporting and writer of the year awards from the N.Y. Press Association. She is a founder, owner and co-publisher of this website.Email Denise.