ALBANY – A 50-year-old New Rochelle man attended a few events at his local synagogue the weekend before last — a bat mitzvah, a funeral, regular services. Hundreds of other people were there, too.

Around that time, he started showing some signs of illness. But he had no reason to suspect he had the new coronavirus; He hadn't traveled to China, Iran or any of the other hotspots for the global outbreak, after all.

Flash forward to Thursday: The man, an attorney now confirmed to have the coronavirus disease, remains hospitalized. Seventeen other people connected to him — friends, family members, a health care worker — have also tested positive.

And some people he and his family may have come in contact with at the synagogue traveled to Washington D.C. this week, where they attended a conference that drew thousands of people and featured appearances by major government figures, including Vice President Mike Pence.

The New Rochelle case offers a textbook look at how the novel coronavirus can quickly spread to those in close contact with the infected, leading state and local health officials earlier this week to issue a widespread self-quarantine order to those who may have crossed paths with the man.

More:Coronavirus: New York has 22 confirmed cases, including 18 in Westchester

Now, disease detectives are continuing to piece together who may have had contact with the man, then finding people who those people had contact with in hopes of containing the spread.

New York Gov. Andrew Cuomo called the New Rochelle case the "most complex" the state is dealing with because of the number of contacts the patient had.

"The attorney worked in a law firm in Manhattan," Cuomo said Wednesday. "The family is in Westchester. They had attended schools. They had been to synagogue services with hundreds of people. So it's the most complex investigation matter."

More:Coronavirus in New York: State officials may wrestle with expanding quarantines as cases spread

Synagogue members traveled to AIPAC conference

Already, the tentacles of the investigation into the man's contacts have reached to the highest levels of government.

The Young Israel synagogue where the New Rochelle man attended sent a contingent of members at the AIPAC conference in Washington D.C. this week, a widely attended pro-Israel event that drew thousands of attendees from across the country.

The conference featured speeches from Pence, Secretary of State Mike Pompeo and U.S. Senate Minority Leader Charles Schumer, among many others.

On Wednesday, AIPAC — the American Israel Public Affairs Committee — reached out to attendees, advising them that a group that attended may have had contact with the New Rochelle man who tested positive for coronavirus.

"Although we have been told by the DC Health Department that there is no reason to 'sound the alarm,' we want to be sure all Policy Conference attendees have the information we have at this time," AIPAC President Betsy Berns Korn and Chairman Mort Fridman wrote in an email.

Marshall Wittman, a spokesman for AIPAC, said the committee was in consultation with a variety of governmental agencies — including the World Health Organization and the CDC — in the months leading up to the event.

"We worked closely with the Washington Convention Center to create a safe and hygienic environment by increasing the number of hand-sanitizer dispensers, adding additional cleaning crews to disinfect high-traffic areas, and deploying signage to encourage hand-washing and other recommended behaviors," Wittman said.

The potential coronavirus exposure for AIPAC attendees is considered by the DC Health Department to be "low risk," according to the committee.

More:Coronavirus in New York: Another New Rochelle family tests positive as 1,000 local people quarantined

How the coronavirus spreads

The new coronavirus is believed to be transmitted primarily from person-to-person contact, according to the U.S. Centers for Disease Control and Prevention.

It can be spread from contact with an infected person, which the CDC defines as being within about six feet.

It can also spread through respiratory droplets from a cough or sneeze that someone else inhales or is touched by.

The symptoms of COVID-19, the disease caused by the new coronavirus, are similar to a cold or other respiratory illnesses. They can be exacerbated by an existing condition, as is the case of the original New Rochelle man, whose condition was improving Thursday.

About 80% of those who develop the disease will see their symptoms self-resolve, Cuomo said.

New York City Mayor Bill de Blasio said Thursday the city is most focused on people who have been in direct contact with an infected person.

“What we’re concerned with is direct contact with fluids,” de Blasio said at a briefing.

He urged people to take steps like washing their hands and using alcohol-based hand sanitizer.

“All those basics really matter," he said.

More:Coronavirus scams: What you need to do to protect yourself from being ripped off

Coronavirus cases continue to rise

The number of confirmed coronavirus cases continue to rise in New York.

The state had its first case on Sunday: A health care worker from Manhattan who had recently traveled to Iran.

On Tuesday, the state announced the New Rochelle attorney — who works in Manhattan — also tested positive. Nine people connected to the man followed Wednesday, as did eight more Thursday.

All told, there were 22 confirmed cases statewide as of Thursday afternoon, according to Cuomo.

“The more you can do to contain and limit the spread, the better," Cuomo said Thursday.

"We’re doing with these cases the same thing we’re doing with the others: You find the case, you then investigate and track back, you find as many contacts as possible, contact those people and go through the same process over and over again.”

More:An upstate NY couple spent four weeks in a coronavirus quarantine. Here's what they did next.

Jon Campbell is a New York state government reporter for the USA TODAY Network. He can be reached at JCAMPBELL1@Gannett.com or on Twitter at @JonCampbellGAN.

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