The goal, the governors said, was to maintain the hard-fought gains against the virus that have been made, at great economic and human cost, over the past three months. On Monday, for example, nearly 49,000 people were tested for the virus in New York, with just shy of 600 coming back positive.
Since the middle of March, New Yorkers have largely abided by the orders to stay at home and wear masks in public, creating a new way of life in the city and surrounding suburbs that helped to bring new infections down to a manageable level.
At the same time, many New Yorkers with the means to do so fled, often to out-of-state locales. By late March, Florida began requiring travelers from the New York area to quarantine. Other states sought to restrict visitors.
Now, the virus appears to be spreading far more rapidly outside of New York, with new infections surging in places like Arizona and Texas. Those who left for other states, upon their return to New York, will have to quarantine.
The city and state have begun a phased reopening of business that has been more cautious than other areas of the country, and Mr. Cuomo as well as other officials have been concerned about a resurgence of the virus. The travel restrictions were an attempt at mitigating the risk of new infections coming from outside the state.
“We now have the virus under control. Yeah, but Florida doesn’t, Texas doesn’t, these other states don’t,” he said last week. “And what happens if they get on a plane and they come to J.F.K.? So, we get the infection rate down and then because other states are high, we could have a problem.”
Epidemiologists do not see a uniform coronavirus wave spreading across the country, but multiple outbreaks that are out of sync with each other. In that context, they said, quarantine requirements made sense.
They also cautioned that the outbreak remains active and that the situation in any one state or region of the country could still change.