NEBRASKA — The United States on Monday imposed restrictions on American travelers exposed in dual Ebola and hantavirus outbreaks, declining to bring home an American doctor sickened by Ebola and moving six other people with exposure to the virus to Germany and the Czech Republic. The U.S. also required certain passengers from the MV Hondius to remain in a Nebraska biocontainment facility until May 31.

The American Ebola patient was hospitalized in Germany in stable condition, while other U.S. citizens were en route to Germany or Czechia. Czechia has an existing relationship with the U.S. State Department and the Administration for Strategic Preparedness and Response.

"These people, who remain asymptomatic, are being moved to ensure that they have access to the specialized care if needed," said Satish Pillai, Ebola response lead at the U.S. Centers for Disease Control and Prevention. "These locations were chosen based on the needs that were present at that time," he added. Pillai declined to confirm that the decision not to bring at-risk Americans home was made by the White House, which opposed bringing at-risk Americans home in the current outbreak.

Officials initially ruled out mandating quarantine for passengers on the MV Hondius when they were flown back to the U.S., but later required certain passengers to remain in the Nebraska facility, despite some passengers attempting to leave and quarantine at home. The decision to require passengers to stay in Nebraska reportedly came from Jay Bhattacharya, who is performing some duties of CDC director until the nominee is confirmed by the Senate.

"The decision was made across the leadership in the US government to have the passengers stay in Nebraska until 31 May, which marks the 21st day of their monitoring period," said David Fitter, hantavirus lead at the CDC.

Angela Perryman said she had tested negative for the Andes virus, had no symptoms, and would like to quarantine in an Airbnb in south Florida. A 30-year-old passenger said he would like to quarantine in New York state after exposure to the Andes virus.

"US citizens and green card holders have a legal right to return to the United States," said Alexandra Phelan, associate professor at Johns Hopkins Bloomberg School of Public Health. "The order on travel restrictions issued on Monday is clear that it doesn't apply to US citizens," she said. "The US has some of the best biocontainment facilities, medical care and treatment options in the world, and millions of dollars have been poured into these facilities for exactly this situation," Phelan said. "Doubt about whether health workers and other outbreak responders may return to the US could mean fewer Americans volunteer to help stop the outbreak," she added. "Any other indications that Americans are being prevented from returning home in some way, shape or form, would serve as disincentives to support that may be absolutely vital to the international response to this growing crisis," Phelan said. "Any public health measure that is imposed has to be based on reasonable scientific evidence or principles, and has to be proportionate and necessary to achieve the public health outcome," she said. She noted that "the least restrictive measure necessary to achieve the public health outcome" is the guiding concept in global health law. "Most people want to follow quarantine directions, but they may be more comfortable in their own home, where the long quarantine time may be more bearable," Phelan said.