How New York’s spiraling coronavirus outbreak could affect Mass.

Alam has largely stayed home for the past two weeks and hasn’t felt sick, but he is still refraining from visiting his nearby grandmother for fear of unknowingly infecting her.

The outbreak in Massachusetts — with 1,838 cases and 15 deaths so far — is likely driven far more by local transmission than any potential spillover from New York, said Samuel Scarpino, an epidemiologist at Northeastern University.

Even so, he said, the large number of people who regularly travel between New York City and Boston may have unwittingly increased infections locally. Many people are unaware that they are contagious because they experience mild or no symptoms, and even serious symptoms can take up to 14 days to appear, he said.

Over the past two weeks, Massachusetts officials have ordered the closures of schools and nonessential businesses, and urged residents to keep 6 feet from others and stay home. Those efforts, before the outbreak ballooned, positioned Boston and the state well, Scarpino said.

“Our risk from what’s happening in New York City is much lower now than if we were still doing business as usual here,” Scarpino said. “We just need people to take it seriously.”

It’s not surprising that New York has become a hotbed of the virus, he said, because it’s densely populated, home to nearly 20 million people, and a major hub for international and domestic travel.

White House officials said Tuesday that they now view New York City as a coronavirus hot zone, akin to areas of China or Europe. About 60 percent of the country’s new cases were in the New York City metro area, and the infection rate there was eight to 10 times greater than in other parts of the country, officials said.

White House officials asked New York City residents to avoid nonessential travel and if they must leave, to self-quarantine for 14 days.

The spiraling number of New York cases reflects the behavior of people two or three weeks ago, when taking into account the virus’s two-week incubation period, said Nadia Abuelezam, an epidemiologist at Boston College.

“This is not a reflection of how well social distancing is working now,” she said. “Hopefully in a few weeks we’ll see the impact of social distancing” and the cases will stop rising and start to fall.

New York’s high number of cases could also signal that the city is further along than Boston is on its epidemic curve, meaning its first case was introduced earlier, Abuelezam said.

Boston Mayor Martin J. Walsh pointed to the situation in New York on Wednesday as a dire warning of what could unfold here, reinforcing the need for people to follow the social distancing restrictions.

Clea Matt, 19, a freshman at Pace University in Manhattan, moved back to her parents’ home in Danvers on Sunday. She recently developed breathing troubles and a dry cough, possible symptoms of coronavirus. She was tested and is awaiting the results. In the meantime, she has avoided hugging her father, a nurse, and tried not to touch anything in the kitchen.

“I know it’s the safer choice for me to go home because New York is the epicenter,” she said, but she fears spreading the infection. “I could just have this cold, but it could be a lot worse for someone else.”

Florida announced Monday that it would require passengers on flights from New York, New Jersey, and Connecticut to isolate for two weeks after arriving in the state.

Even if it were possible, placing special restrictions on New Yorkers arriving in Massachusetts would not be expected to make a big dent in Massachusetts’ epidemic, Scarpino said. In Seattle, most cases were locally transmitted, not linked to travel, he said.

Travel restrictions only work well in places with no local outbreaks, he said, which are tough to identify in the United States because of a widespread shortage of testing kits.

Boston is not alone in its close ties with New York City, said Robert Puentes, president and CEO of the Eno Center for Transportation, a nonprofit think tank. The New York City region is part of trade and travel networks that stretch across the country and the world.

“Clearly there is a connection between Boston and New York, but I’m not sure it’s greater than . . . with any other of the places with whom it has global trading connections,” Puentes said.

Chris Dempsey, former assistant secretary of transportation in Massachusetts, said it helps that the governors of both states are taking the crisis seriously. Many of the buses, trains, planes, cars, and trucks that normally shuttle between the two regions constantly are now parked.

“Certainly the travel between those two places now is a small fraction of what it would have been,” he said.

Dempsey said it is important to remember that while the proximity and density of the two metro areas now might seem scary, in good times that is a great asset of both places.

“Maybe in times like this we’re thinking we’d rather be Omaha or Kansas City, but in any normal time we would much rather be Greater Boston or New York City,” said Dempsey, who now runs the group Transportation for Massachusetts.

New York Governor Andrew Cuomo reflected on that point too, saying at a news briefing that the physical closeness among New Yorkers is what makes it special — though it’s also driving the outbreak.

“That is what New York is," he said. “Your greatest weakness is also your greatest strength."

Naomi Martin can be reached at naomi.martin@globe.com.