New York, Jul 17 (IANS): Sequences of most of the early COVID-19 positive specimens in New York City resembled those circulating in Europe, suggesting probable introductions of the virus from the continent, other US locations, and local introductions from within New York, the Centers for Disease Control and Prevention (CDC) said.

To determine whether local transmission of COVID-19 could be detected, the NYC Department of Health and Mental Hygiene (DOHMH) conducted deidentified sentinel surveillance at six hospital emergency departments during March 1 to 20, the CDC said a report on Thursday.

DOHMH announced sustained COVID-19 community transmission on March 8, before the US imposed travel ban from Europe on March 13, according to the report.

At this time, 26 NYC residents had tested positive for COVID-19, Xinhua news agency reported.

The following week, on March 15, the level of community COVID-19 transmission status was elevated from sustained to widespread community transmission, said the CDC.

"Although travel restrictions are an important mitigation strategy, by the time the European restrictions were implemented, importation and community transmission of COVID-19 had already occurred in NYC," said the report.

Through sentinel surveillance from March 1 to 20, DOHMH collected 544 specimens from patients with influenza-like symptoms, 36 tested positive.

"Using genetic sequencing, CDC determined that the sequences of most COVID-19 positive specimens resembled those circulating in Europe, suggesting probable introductions of COVID-19 from Europe, from other US locations, and local introductions from within New York," said the report.

The sequence from March 2, the earliest positive sentinel specimen collected, clustered with early sequences from Europe and US, which also cluster with sequences from China, said the CDC.

"No sentinel sequences were directly connected to sequences from Wuhan, China, where the outbreak originated," said the report.