The order came in a letter Wednesday to the American Society of Tropical Medicine and Hygiene, which made clear it did not agree with the decision. Several doctors, including some from the World Health Organization and the Centers for Disease Control and Prevention, now may not be able to attend or present studies at the meeting, which runs Sunday through Wednesday.
State officials said a similar letter will go to organizers of the American Public Health Association, which plans its annual meeting in New Orleans Nov. 15-19.
The letter acknowledges that even people infected with the Ebola virus do not spread the disease unless they are showing symptoms. But it says that because people with a travel or exposure history to Ebola should avoid large group settings, "we see no utility in you travelling to New Orleans to simply be confined to your room."
It is signed by Kathy Kliebert, secretary of the state's Department of Health & Hospitals, and Kevin Davis, director of the Governor's Office of Homeland Security & Emergency Preparedness. It cites travel within the last 21 days — Ebola's maximum incubation period — to Liberia, Guinea or Sierra Leone as being a problem.
The tropical medicine group noted that the state's stance goes beyond CDC guidelines. Its president, Dr. Alan Magill, called the order "unfortunate" and "a pretty tough message to send out, particularly to our international colleagues," who were gathering to share knowledge on how to beat back Ebola and other global health problems.
"We certainly have folks who know this disease very well and we were looking forward to having world experts discuss it," said Magill, also an official at the Bill & Melinda Gates Foundation. Microsoft cofounder Bill Gates is to speak at the conference's opening session on Sunday.
Magill said he did not know how many of the 3,500 registered for the conference would now not be able to attend, but added, "I'm sure some people will choose not to come out of protest" to Louisiana's stance.
"I don't agree with it at all," said Dr. John Schieffelin, an infectious diseases expert at Tulane University in New Orleans who will attend the conference. He just published a study in this week's New England Journal of Medicine giving the most detailed information yet on symptoms and treatment of Ebola cases in Sierra Leone, and returned from that country in August.
"It's just one more thing that's going to slow down the science and research effort" and ultimately could hurt control of the disease, Schieffelin said of the state's policy. It's an overreaction to perceived risk and "comes off as a little xenophobic," he said.
Dr. Frank Welch, medical director for the state health department's centre for community preparedness, said the state acted because the CDC just last week put stricter protocols in place for evaluating travellers from Ebola-affected countries, and some of the travellers to the upcoming medical meetings may have been exposed to Ebola before the new CDC rules.
"We have no way to assess their contact during that three weeks," and so are being "over-cautious," Welch said.
He said his department was working with conference leaders to arrange electronic presentations of studies from presenters now not able to attend in person.
"We do not want to diminish their expertise" or deprive their colleagues of the opportunity to hear from them, he said.
In contrast to the Louisiana situation, there were no such restrictions placed on doctors attending the American College of Emergency Physicians' annual meeting in Chicago this week, said Julie Lloyd, a spokeswoman for the group.
Chief Medical Writer Marilynn Marchione reported from Milwaukee. AP Medical Writer Lindsey Tanner in Chicago contributed reporting.