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St. Louis Cathedral in New Orleans, the host city for this year's ASTMH meeting.

St. Louis Cathedral in New Orleans, the host city for this year's ASTMH meeting.

Jason Mrachina/Flickr (CC BY-NC-ND 2.0)

Been to an Ebola-affected country? Stay away from tropical medicine meeting, Louisiana says

Ebola fears are interfering with the world's premier scientific meeting on tropical diseases. Today, Louisiana state health officials asked anyone who has traveled to Liberia, Sierra Leone, or Guinea in the past 21 days, or has treated Ebola patients elsewhere, to stay away from the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH), which begins on Sunday in New Orleans.

ASTMH doesn't know exactly how many scientists will be affected, but there are several, says incoming president Christopher Plowe, including representatives from the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC). "They are quite disappointed," says Plowe, a malaria researcher at the University of Maryland School of Medicine in Baltimore. ASTMH sent all meeting registrants an e-mail today containing a letter from Kathy Kliebert, secretary of Louisiana's Department of Health and Hospitals, and Kevin Davis, director of the Governor’s Office of Homeland Security and Emergency Preparedness, that outlines the state's position. ASTMH referred registrants to the state's health department for further information.

"Given that conference participants with a travel and exposure history for [Ebola] are recommended not to participate in large group settings (such as this conference) or to utilize public transport, we see no utility in you traveling to New Orleans to simply be confined to your room," the letter says.

Louisiana's new policy goes further than guidelines from CDC; it is the latest example, after New York and New Jersey, of a state deciding to impose restrictions that many scientists say make little sense.

"I'm very upset. And that's an understatement," says Piero Olliaro, a tropical diseases expert at WHO and a visiting professor at the University of Oxford in the United Kingdom, who learned this afternoon that he can't travel to New Orleans. Olliaro returned from Guinea on 22 October, where he had been scouting for sites to do clinical trials of candidate Ebola drugs. At the ASTMH meeting, he was scheduled to co-chair a session, give two talks, and present six posters. He says he's scrambling to find people to replace him.

"This policy is fundamentally flawed and not evidence-based," says Daniel Bausch, a researcher at the Tulane University School of Public Health and Tropical Medicine in New Orleans who is the organizer of one of two specialized Ebola symposia at the meeting. "It's very unfortunate and could potentially be counterproductive by preventing health care workers from Liberia, Sierra Leone, and Guinea from sharing their experiences and findings at one of the most important tropical disease meetings globally," adds Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, Texas.

Plowe says he made phone calls to state officials late into the night the past few days to get clarity on Louisiana's Ebola policy in time for this year's meeting. "The last thing we wanted was for people to travel to New Orleans only to find out that they will be quarantined for 21 days," he says. Louisiana has the right to make its own policies, Plowe says: "That's the way it is. We have to live with it." But ASTMH believes the best way to protect Americans is to fight Ebola in West Africa, he adds, and keeping away health care workers who have not been involved in patient care "is not helping to accomplish this, and ultimately puts Americans at higher risk," he says.

Just how to limit the spread of Ebola in the United States has become the topic of intense political debates in the middle of an election season. According to the complicated new interim guidelines from CDC issued yesterday, people who have traveled to countries with widespread Ebola transmission but who did not come into direct contact with patients, are in the "low (but not zero) risk" category; the same is true for those who treated Ebola patients using appropriate personal protective equipment (PPE) in countries that have seen just a few cases, such as the United States, Germany, or Spain. As long as they have no symptoms, such people can travel freely, and there is no reason to bar them from gatherings, CDC says.

People who treated Ebola patients using protective gear in Sierra Leone, Guinea, or Liberia fall into the "some risk" category, for which "direct active monitoring" is recommended, including daily temperature measurements by health officials; in addition, local authorities "may consider additional restrictions," CDC says. (The definitions of the various risk categories are here.)

That gives state authorities considerable leeway, and some have decided to take a strict position. In their letter, Kliebert and Davis say that the state wouldn't be able to determine the level of risk for any particular traveler; instead, it would have to rely on self-reporting. To err on the side of caution, Louisiana is asking even people who fall into CDC's "low (but not zero) risk" category to stay away. "In Louisiana, we love to welcome visitors, but we must balance that hospitality with the protection of Louisiana residents and other visitors," the letter says.

Kliebert and Davis appear to acknowledge that the ban does not make much sense scientifically, however. "From a medical perspective, asymptomatic individuals are not at risk of exposing others," they write. "These precautions are being taken out of an abundance of caution for the current situation, and certainly do not reflect a lack of appreciation for your service and sacrifice in efforts to treat and end the [Ebola] epidemic.

"Out of an abundance of caution … I've come to hate that term," Bausch says. "It means it's not evidence-based, there's no science to support it, but we're going to do it anyway."

Olliaro says he didn't treat patients in Guinea but walked around Ebola treatment units in a protective suit; this would probably put him in CDC's "some risk" category. In the United Kingdom, by contrast, he is supposed to self-monitor, his travel isn't restricted, and he can go to meetings.

Bausch's session at the ASTMH meeting will be a broad overview of the state of the epidemic. Bausch has repeatedly traveled to West Africa himself, but not in the past 21 days; he's not sure if anyone in his panel has. Another session at the meeting will focus on new drugs and vaccines. ASTMH says it will reimburse conference fees for registrants who decide to cancel their trip because of Louisiana's Ebola policy.

"We do hope that you will consider a future visit to New Orleans," Kliebert and Davis say at the end of their letter, "when we can welcome you appropriately."

*The Ebola Files: Given the current Ebola outbreak, unprecedented in terms of number of people killed and rapid geographic spread, Science and Science Translational Medicine have made a collection of research and news articles on the viral disease freely available to researchers and the general public.