The first travel-associated case of Ebola in the United States has raised concerns once again about whether flights should be restricted from the West African countries ravaged by the epidemic. On Friday, Louisiana’s Republican governor Bobby Jindal called on the Obama administration to ban flights from countries with the Ebola outbreak from coming into the U.S., a move partly fueled by reports that Thomas Eric Duncan, the Liberian man who developed symptoms after flying into the U.S., may have lied on an airport screening questionnaire about his contact with infected individuals.
But most public health experts recommend against restricting air travel from West Africa, arguing that it would be counterproductive to curbing the spread of the disease and may, in fact, exacerbate the problem.
According to the World Health Organization, there have been 7,178 total cases of Ebola virus disease in Guinea, Liberia, Sierra Leone, Nigeria and Senegal, and the death toll stands at 3,338.
While a number of airlines such as British Airways, Kenya Airways, Air Cote D’Ivoire, Arik Air and others have suspended flights from high-transmission countries Liberia, Sierra Leone and Guinea, the World Health Organization does not recommend any ban on international travel as a means to contain the disease. International flights in and out of cities like Monrovia and Lagos are still available, as a recent Kayak.com search revealed.
“The widespread opinion among public health officials is that cutting off flights is not a good idea at all,” said Dirk Brockmann, who studies epidemiological modeling of infectious diseases at the Robert Koch Institute in Berlin.
“If you start cutting off flights from these countries, people will just go somewhere else to find ways out, and the situation will become even more unpredictable. The only way this outbreak can be solved is for us to go there and help contain it. We need transportation to these countries," he said.
Because Ebola is not airborne and can be transmitted only by direct contact with body fluids of a person who is sick and exhibiting symptoms of the disease, most experts agree that the risk of transmission on airplanes is low.
Passengers departing from airports in West Africa must undergo several screening protocols, including testing them for signs of fever, an early indicator of the disease. In September, around a dozen people were prevented from boarding planes in West Africa because they had a fever, reports the CDC. Most of them did not have Ebola, but transit authorities have been trained to be extra cautious.
But Duncan was not exhibiting any signs of the disease when he left Liberia on Sept. 19, says the CDC. Mark Gendreau, an emergency physician who specializes in aviation medicine, said that Ebola is only contagious once a person is exhibiting active symptoms. Duncan could not have spread the disease to fellow passengers at that time. As such, the CDC was not tracking passengers who were on the same flights as Duncan. United Airlines, which carried Duncan on two legs of his flight, is voluntarily contacting fellow passengers anyway.
Most experts who create mathematical models to study the way diseases like Ebola travel around the world agree it was a matter of time before an asymptomatic passenger carrying the disease would board a flight and carry the virus to another part of the world.
“This is something we were expecting to occur. The fact that we have had one importation is not that surprising,” said Gerardo Chowell-Puente, associate professor of mathematical epidemiology at Arizona State University. “The odds for the U.S. were low, but higher for other countries closer to the affected ones.”
Allesandro Vespignani, a Northwestern University professor who runs a model projecting Ebola’s spread, told the Washington Post on Sept. 24 -- just one day before Duncan first sought treatment at a Dallas hospital -- that there was a 10 percent chance of the disease getting imported to the U.S. within the next week.
But that’s not a reason for hysteria in countries like the U.S. where public health infrastructures are strong, say experts.
“The key here is that as soon as someone comes down with a disease like Ebola, if you can immediately isolate that person and track down the people they came into contact with when they started feeling sick, you can quickly contain that infectious disease,” said Gendreau. “That’s why SARS was so rapidly brought under control -- when it spread to Hong Kong and the western part of the world, there were enough public health resources available to isolate and quarantine the sick.”
The lack of such resources in places like West Africa is why the epidemic has spread so quickly. According to the CDC, 82 percent of Ebola patients in Liberia are treated at home. In order to contain the epidemic, that number needs to be brought down to 30 percent.
Thomas Frieden, the director of the Centers for Disease Control, agreed, saying a ban on flights would only backfire. “The best way to protect ourselves is not to seal off these countries but to provide the kinds of services so the disease is contained there. The only way to get to zero risk is to stop it there,” he said in a news conference on Thursday.