The arrival of the omicron variant of the coronavirus in the U.S. has health officials in some communities reviving contact tracing operations in an attempt to slow and better understand its spread as scientists study how contagious it is and whether it can thwart vaccines.
In New York City, officials quickly reached out to a man who tested positive for the variant and had attended an anime conference at a Manhattan convention center last month along with more than 50,000 people. Five other attendees have also been infected with the coronavirus, though officials don’t yet know whether it was with the omicron variant.
“As for what we learned about this conference at the Javits Center and these additional cases, our test and trace team is out there immediately working with each individual who was affected to figure out who else they came in contact with. That contact tracing is absolutely crucial,” New York Mayor Bill de Blasio said.
Once a global epicenter of the pandemic, New York has the country’s biggest contract tracing effort. The city identified four omicron cases Thursday, and a fifth was discovered in nearby Suffolk County on eastern Long Island.
The variant has been detected in a handful of other states so far, including California, Colorado and Hawaii.
Contract tracers have been busy in Nebraska after six cases of omicron were confirmed Friday. One of the people had recently returned from a visit to Nigeria, and the other five were close contacts of that person.
In Philadelphia, officials were working to track down contacts of a man in his 30s who is Pennsylvania’s first resident infected with the variant, the city’s Department of Public Health said.
And in Maryland, officials were rushing to trace, quarantine and test close contacts of three people from the Baltimore area who are the first known cases in the state. Two are from the same household, including a vaccinated person who recently traveled to South Africa, and the third has no recent travel history and is unrelated to the other two.
Dr. Marcus Plescia, chief medical officer of the Association of State and Territorial Health Officials, said “more and more” contact tracing efforts are expected in the coming days, in part because of the uncertainty about how effective vaccines and treatments like monoclonal antibodies will be against omicron.
Contact tracing is a vital tool in the pandemic response, allowing health departments to notify people who had close contact with an infected person and slow the progression of COVID-19.
“Contact tracing can give us information about how it’s spreading and hopefully break chains of transmission to stop clusters and outbreaks, or at least delay them until we know more and understand what our next steps need to be,” said Crystal Watson, a senior scholar at the Johns Hopkins Center for Health Security at the Bloomberg School of Public Health. While much is still unknown about the variant, early reports are raising alarms. New COVID-19 cases in South Africa, which first alerted the world to omicron last week, have burgeoned from about 200 a day in mid-November to more than 16,000 on Friday.
Some of the U.S. cases involve people who hadn’t traveled recently, meaning the variant was likely already circulating domestically. In New York, the three-day anime festival in November is presenting a staffing challenge for tracers due to the large number of attendees. The one known omicron infection involved a man from Minnesota.
Officials cautioned against linking the other five coronavirus cases directly to the event.
“The really important point here is that’s five cases from a denominator of tens of thousands of people at this conference. And furthermore, we’ve not established any sort of link between those five cases and widespread transmission at the conference,” said Ted Long, executive director of the NYC Test &Trace Corps, which runs the city’s contact tracing program.