The head of the U.S. Centers for Disease Control and Prevention rejected lawmakers’ calls to ban travelers from three West African nations gripped by an Ebola outbreak, arguing it could increase risks to Americans.

Confirmation that a Dallas health-care worker is infected after treating an Ebola patient who died has put a new focus on risks the virus will spread. Texas lawmakers led by Republican Representative Kenny Marchant are urging Secretary of State John Kerry to suspend U.S. visas from Liberia, Sierra Leone and Guinea, where Ebola has killed more than 4,000 people this year.

Tom Frieden, the CDC’s director, said flights to and from the region are needed for health workers and supplies to help combat the disease. While the outbreak remained unchecked, there’s no way to eliminate all risk to Americans, he said.

“It may make it much harder to stop the outbreak at its source,” Frieden said at a briefing today when asked about calls for a ban. “The way we’re going to reduce threats to Americans is stopping” the disease in Africa, he said.

The virus has killed almost half the people infected in the three African nations. The World Health Organization ruled out travel restrictions based on an assessment that showed the disease isn’t spread through the air, a decision that led the International Air Transport Association in Geneva to oppose a ban on flights to the region.

Aviation Lifeline

“Aviation is a lifeline for these nations, and a provider for these markets,” said Chris Goater, a spokesman for the airline group. “There is a lot of disquiet among the flying public.”

Without a WHO decision to limit travel, a U.S. travel ban would both “violate international law and be unethical,” said Lawrence Gostin, a Georgetown University professor who has written on the health-related travel issues. “It would cause enormous human problems, and would make the epidemic harder to control.”

The current system is “imperfect,” but better than a ban — for now, said Ronald Bayer, a co-director of the Center for the History and Ethics of Public Health at Columbia University.

“The problem with a total travel ban is that it feeds a sense of isolation and hysteria,” Bayer said. “It would be disruptive and dangerous.”

U.S. agents at John F. Kennedy International Airport yesterday began added screening of passengers who began their trips in one of the three nations. In total, 91 people were pulled aside for special questioning. None had a fever, and five were asked more questions by a health worker, Frieden said.

Airport Checks

The new airport checks started three days after the first U.S. death from Ebola. The patient, Thomas Eric Duncan, arrived in Dallas from Liberia on Sept. 20 and didn’t show signs of the disease until Sept. 24. He died at Texas Health Presbyterian Hospital, where the health-care worker was an employee.

Of the 275,000 international passengers daily, about 150 — or less than 0.1 percent — come from at-risk regions in Africa.

The U.S. screening adds to measures taken by the three African nations, which require travelers to complete a health questionnaire, be visually assessed and have their temperature taken before leaving the region.

Those two sets of reviews aren’t enough for many lawmakers.

“If we were really treating this as a public health issue why would we not immediately stop these flights,” Representative Joe Barton, a Texas Republican, said at a hearing with federal health and border officials in Dallas last week. “You’re almost guaranteeing mathematically we’re going to miss some people” with Ebola, he said.

To contact the reporter on this story: Mark Drajem in Washington at mdrajem@bloomberg.net To contact the editors responsible for this story: Jon Morgan at jmorgan97@bloomberg.net Steve Geimann, Elizabeth Wasserman.

Tags: cdc, safety, usa
Photo Credit: Thomas Frieden, CDC director, gives an update on Ebola at the Kaiser Permanente Center for Total Health. Ted Eytan / Flickr