The next worry: Will Ebola spread through transportation networks?

People being monitored after exposure to a person with Ebola should not travel by airplane, train or bus, federal authorities said Wednesday, as concern shifted to preventing the infectious disease from spreading through transportation networks.

The travel restrictions were announced after the revelation that a nurse with Ebola flew from Cleveland to Dallas/Fort Worth Airport the day before she fell ill. Amber Joy Vinson, 29, a registered nurse, was among 76 people who cared for Thomas Eric Duncan, who died Oct. 8 at Texas Health Presbyterian Hospital Dallas after contracting Ebola in Liberia.

Health officials said they are now directing more than 125 people who had contact with Ebola patients not to travel to avoid exposing others to the virus and possibly creating an outbreak in the United States. The number of people being monitored is likely to grow, but Centers for Disease Control and Prevention officials didn’t provide an updated number of possible Ebola contacts Wednesday.

Vinson had a temperature of 99.5 on Monday and should not have been on a commercial flight, CDC Director Thomas Frieden said Wednesday. She did not meet the fever threshold of 100.4 degrees, at which point she would have been obliged to notify Texas Health Presbyterian that she was displaying Ebola symptoms, Frieden said.

Nonetheless, out of an abundance of caution, she should not have traveled in an enclosed area with other members of the public, he said, “by virtue of the fact she was in an exposed group.” Even so, he said, she did not vomit and was not bleeding, so the risk to other passengers was low.

One official said Vinson had called federal health officials before boarding the plane to report having a slightly elevated temperature but was allowed to fly, The New York Times reported.

Pressed for details about how at least 125 people being monitored for Ebola symptoms in Dallas-Fort Worth could be prevented from boarding a plane or using public transit, Frieden said that would be up to state and local authorities. He did not elaborate.

He did say that those possibly exposed to Ebola could travel by private automobile.

DART stops at hospital

Officials at North Texas public transit agencies said they are reviewing their vehicle-cleaning procedures and will provide health information to customers as needed.

“As for our customers and employees, we continue reinforcing the same messages since the first case was reported. The risk of contracting the Ebola virus in a transit setting, compared with cold and flu viruses, is comparatively low,” said Morgan Lyons, spokesman for Dallas Area Rapid Transit.

“It is especially low when we all practice common-sense hygiene — especially during the cold and flu season. The virus doesn’t travel through the air, like the cold and flu. President Obama made that same point in a statement earlier today, ‘You cannot get it from casual contact, like sitting next to someone on a bus,’ ” Lyons said. “… We join local, state and federal officials in urging customers to remember their risk of exposure is low and to remain calm.”

On a typical weekday, DART carries an average of 120,192 riders by bus and 94,399 riders by rail. Also, an average of 8,401 riders per day use the Trinity Railway Express, which connects downtown Fort Worth to Dallas.

Healthcare workers are among the most common users of public transportation in DFW. In Dallas, two light-rail lines stop about every 15 minutes at Walnut Hill Station, which is practically at the front door of Texas Health Presbyterian in east Dallas.

Trains also stop at stations near other hospitals, including those in the Medical District in Dallas.

‘Stepping up’ bus cleaning

The Fort Worth Transportation Authority, also known as the T, co-owns TRE with DART. The T’s bus system and other transportation services carry about 28,000 riders per weekday, according to the T’s monthly ridership records.

The agency is taking extra care to clean its buses, T President Paul Ballard said. The T also has an ultraviolet-light system in its heating and air-conditioning units aboard buses that is designed to kill germs and virus-carrying particulates.

The UV system helps prevent the spread of colds and the flu but would not be considered effective in preventing Ebola, which is transmitted by direct contact with bodily fluids such as blood and urine.

“We’re stepping up our bus cleaning,” Ballard said. “Every night, our cleaners are scrubbing down the surfaces people come into contact with, with Lysol.”

He added that the agency will take buses out of service every six weeks for a more detailed cleaning in response to concerns about contagious diseases. Traditionally, buses have been taken out of service about four times a year.

Screenings at airports

DFW Airport officials referred questions about the Ebola threat to Tarrant County Public Health, where officials said they are formulating a plan to spread the word about Ebola at transportation centers.

“Right now, they’re reassessing some things and updating some additional protocols, I believe, that we’re getting from CDC,” Tarrant County Public Health spokesman Al Roy said.

Nationwide, advanced screenings for Ebola began Saturday at New York’s John F. Kennedy Airport and are scheduled to begin Thursday at four additional airports for international travelers, including Washington Dulles, Chicago O’Hare, Atlanta Hartsfield-Jackson and Newark Liberty. The screenings include questioning travelers arriving from the African nations most affected by Ebola and taking their temperatures.

U.S. Rep. Michael McCaul, R-Austin, speaking last week at a specially called hearing at DFW Airport, said Americans are rightly “concerned because the Ebola virus is an unseen threat and is only a plane flight away from our shores.”

Staff writers Andrea Ahles and Judy Wiley contributed to this report, which includes material from the Star-Telegram archives.