But the Centers for Disease Control and Prevention has no plans to amp up Ebola screenings at U.S. airports, and as the infected patient seems to demonstrate, screenings may not always prevent infected individuals from entering the country.
CDC spokesman Benjamin Haynes told The Huffington Post the agency has no intention of increasing screenings at the nation's airports. Instead, he says, the CDC will continue to advise customs and border control officials about how to spot Ebola symptoms in travelers. The agency will also be providing informational pamphlets that list symptoms of the disease to people traveling from Ebola-affected regions. Haynes suggests travelers monitor their health in the days after their arrival.
On Tuesday, the agency announced the infected patient, who was traveling from Liberia to Dallas, showed no symptoms of the disease upon his arrival in Texas. He began feeling sick a few days later and was tested for Ebola on Monday.
Travelers leaving West Africa already undergo aggressive screening at airports. As the Atlantic notes, people departing countries where Ebola is rampant are all screened -- with the help of devices like this infrared thermometer gun used at the Freetown, Sierra Leone, airport -- for elevated temperatures. (Fever is one of the earliest symptoms of Ebola.)
But according to some healthcare experts, these screenings may not actually be all that useful if they were implemented in the U.S.
Take the patient in Dallas. According to the New Republic, more rigorous health screening at the airport (both the one in Liberia and in Dallas) would not have prevented him from getting on a plane or entering the U.S. So, even if the man's temperature had been screened or he had been asked questions about his health, it's likely nothing would've seemed out of the ordinary, since there were no symptoms.
"[Screening] would not have worked in the case of an asymptomatic person. Airport screeners look for obvious signs, such as high fever and other visible or measurable signs of illness," Howard Markel, a professor of medicine and communicable diseases at the University of Michigan, told the New Republic.
That's the tricky thing about detecting Ebola, experts say. The illness has a long asymptomatic period of between two to 21 days, which means infected people may be able to get through airport screenings without a problem. The only way screenings at the airport could be more airtight, writes DefenseOne.com, is if passengers are made to undergo blood tests. This, however, would be such a massive labor- and time-intensive undertaking that it would slow international air travel "to a halt," the news outlet writes.
Patients are only contagious when they're symptomatic; so in the case of the patient in Dallas, the people who were on the flight from Liberia with him, as well as those he came into contact with at the airport, are not at risk of contracting the illness.
"At this point, there is zero risk of transmission on the flight," said Tom Frieden, director of the CDC, per USA Today.
However, Reuters reports that up to 18 people are now being monitored for signs of the virus after coming into contact with the Dallas patient after he entered the U.S.
The CDC says people should avoid unnecessary travel to countries in West Africa currently affected by the Ebola outbreak.
Thus far, more than 3,300 people have died from Ebola in Liberia, Sierra Leone and Guinea, the World Health Organization reports. Health experts have said, however, that there is no risk in the U.S. of a similar outbreak.