Gov. Greg Abbott issued an emergency order Thursday requiring air travelers from U.S. coronavirus hot spots to self-quarantine upon arrival in Texas.


The mandatory quarantine of 14 days or the length of stay in Texas, whichever is shorter, will apply to most travelers "whose point of origin or point of last departure" came from airports in New York, New Jersey, Connecticut or New Orleans, according to Abbott’s order.


The order came as the Texas death toll rose to 18 and state officials reported, for the first time, the number of patients being treated for COVID-19 in hospitals in the state — 100 as of Thursday afternoon.


Fewer than 10% of those testing positive for the coronavirus have needed hospitalization thus far, Abbott said.


Under Abbott’s executive order, arriving travelers will have to declare their quarantine location and go there immediately after leaving the airport, "leaving only to seek medical care or to depart from Texas."


No visitors will be allowed except for health care providers, and those in quarantine are prohibited from visiting public spaces.


"DPS special agents will conduct unannounced visits to designated quarantine locations to verify compliance," the order said.


Violators face up to 180 days in jail and a $1,000 fine.


Mandatory quarantine will not apply to those traveling "in connection with military service, emergency response, health response, or critical-infrastructure functions," the governor's office said.


Travel into Texas by road will not be monitored.


Abbott said the order, issued under his emergency powers, was based on recent advice from Dr. Deborah Birx, coordinator of the White House coronavirus response, and Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.


"Dr. Birx urged everyone who is traveling from the New York metro area to self-quarantine for 14 days before exposing themselves to the public," Abbott said. "Dr. Fauci also called for this measure to make sure New York does not act, and I quote, as a seeding point to the rest of the country."


Governors in Florida and Rhode Island have enacted similar quarantine requirements for travelers from the New York metro area.


Abbott said the situation in New Orleans prompted travelers from that city to be added to the quarantine order, adding that other areas could be included in the future.


California and Washington state, he said, "would probably be the next ones on the list if we were to expand it."


Abbott announced the quarantine order during a news conference from the Capitol that, like previous updates on the coronavirus response, was carried live online and included limited participation.


According to the governor:


• More than 21,000 Texans had been tested for the coronavirus, with 1,424 positive results, a rate of less than 10%. "We are on a very good trajectory in the increase of the number of people we are testing, and I expect that increase to continue," Abbott said.


• COVID-19 has been identified in 90 Texas counties, up from 39 on Friday.


• The 18 deaths reported in Texas by Thursday afternoon was up from five last Friday.


• More than 3,000 hospital beds have been identified statewide that can be used to treat COVID-19 patients.


Asked about President Donald Trump's hope to reopen many of the nation’s businesses by Easter, Abbott said it’s "way too early to tell right now" when that may take place.


"Everyone understands that we will all be working off of the best advice of medical professionals about what is the safest way to proceed," he said. "We wouldn’t want to suddenly open schools and open businesses only to have to shut them down again."


It might be best to reopen certain businesses, then assess the impact on health and safety before proceeding, Abbott said.


"This is an evaluation that takes place on a constant basis to make the best judgment about when and how we will begin to reopen the economy," he said.


The quarantine mandate followed several coronavirus-related orders issued Wednesday by Abbott, including one allowing hospitals with a pending license, or those that have been closed for less than three years, to open and be run by hospitals with current licenses.


"One of our top objectives is to ensure that COVID-19 patients in Texas who need a hospital bed will have access to a bed," he said.


Abbott also waived requirements from the Texas Board of Nursing to give a six-month grace period to nurses with an expired license, giving additional time to renew without added fees.


Also Wednesday, Abbott sent a letter asking for permission from the U.S. Department of Agriculture to let Texas food stamp recipients use benefits at takeout and drive-thru restaurants.


If approved, 3.2 million Texans on the Supplemental Nutritional Assistance Program could have another food source, he said.