Cruise passengers are quarantining, but for how long? Latest on hantavirus

Officials from the Centers for Disease Control and Prevention said Americans who traveled on the MV Hondius are encouraged to stay quarantining in Nebraska but stopped short of saying they would be kept at the facility for the full 42-day incubation period.

An incubation period refers to the time between a person being exposed to a pathogen, such as a virus, and when they begin exhibiting symptoms.

"Our goal is to continue to work with them to the best possible place for them, and we encourage them to be there," a CDC official said during a call to reporters on Wednesday.

Passengers from the cruise ship at the center of the deadly hantavirus outbreak are at facilities in Nebraska and Georgia.

While the CDC confirmed two passengers are still at Emory in Atlanta, they didn’t share additional details: “Out of respect for privacy, I’m going to stop there."

They also didn't respond to a question about how many people are being monitored. “At this time, we’re not putting out exact numbers. Again, we want to ensure that we are protecting and respect the privacy of all the individuals,” they said.

Earlier in the call, officials added that hantavirus risk to the general public remains low, and the CDC has over 100 staff members actively working on the outbreak.

Eighteen American citizens, including one British dual national, disembarked the ship off Tenerife, Spain, on May 10, before returning stateside. Most went to the University of Nebraska Medical Center, including 15 people staying in standard quarantine units and one in the center's biocontainment unit.

Two passengers, a couple, were taken to a biocontainment unit at Emory University in Atlanta. Officials from the Centers for Disease Control and Prevention said at a May 11 news conference that the two were moved to preserve space at the Nebraska biocontainment unit.

Here's the latest on the hantavirus outbreak.

Americans from MV Hondius test negative

All Americans in quarantine at the University of Nebraska are asymptomatic as of May 12, the Department of Health and Human Services said.

One of the two passengers sent to Atlanta was initially symptomatic but tested negative for the Andes variant as of May 12, per HHS.

HHS also said one American passenger initially tested "mildly" positive for hantavirus after evacuating the ship, so officials indicated they would undergo further testing.

The individual had initially given two specimens for testing, which led to one negative result and one positive result, Capt. Brendan Jackson, physician and acting director of the CDC’s Division of High-Consequence Pathogens and Pathology, said during a news conference at the University of Nebraska May 11.

Spain's Ministry of Health said in a post on X on May 13 that the American with an "inconclusive" test has now tested negative. USA TODAY has reached out to HHS for confirmation.

Dr. Stephen Kornfeld, an American passenger on the MV Hondius, told CNN he was the individual with the "mildly" positive test result.

Kornfeld told the outlet he stepped in as the ship's doctor in April before eventually starting to experience symptoms himself. He recovered, but was tested alongside other ship staff in early May. When two passengers were evacuated to the Netherlands, one of Kornfeld's test samples was also sent to two labs, which turned up different results.

"One lab was negative and one lab was faintly positive, so I was told the test was intermediate, but I think since it wasn't a negative, it's sort of being looked at as a potential positive," he said.

Kornfeld told the outlet that he is currently quarantining in the Nebraska biocontainment unit.

Hospitalized French passenger now on lung support

A French woman who was in intensive care on Tuesday is now on lung support, according to multiple reports.

French Health Minister Stéphanie Rist said Tuesday that the woman, infected with Andes virus, was one of five French nationals repatriated from the ship.

The woman is now being treated with an artificial lung, a doctor at the Paris hospital caring for the sickened passenger said Tuesday, according to the Associated Press and France 24. USA TODAY has reached out to the hospital for comment.

Dr. Xavier Lescure, an infectious disease specialist at Bichat Hospital, told the outlets the passenger has a severe form of the disease that has caused life-threatening lung and heart problems.

The life-support device − which pumps blood through an artificial lung, providing it with oxygen and returning it to the body − is hoped to relieve enough pressure on the lungs and heart to give them some time to recover, the reports add.

Lescure called it “the final stage of supportive care," according to the outlets.

Latest number of hantavirus cases

As of Tuesday, May 12, a total of 11 people around the world have had either confirmed or suspected cases of hantavirus tied to the MV Hondius outbreak, according to the World Health Organization. It's unclear whether this figure has changed due to the American testing negative; USA TODAY has reached out to the WHO for comment.

Nine of the 11 cases have been confirmed as the Andes virus, and the two others are probable, Dr. Tedros Adhanom Ghebreyesus, WHO director-general, said at a May 12 news conference. The number includes the three people who have died from their infections.

All cases are among passengers or crew members from the ship, Ghebreyesus said.

"At the moment there is no sign that we are seeing the start of a larger outbreak. But of course the situation could change and given the long incubation period of the virus, it's possible we might see more cases in the coming weeks," he said.

Possible hantavirus case in Illinois not tied to MV Hondius

The Illinois Department of Public Health said it’s investigating a potential case of hantavirus in an Illinois resident not linked to the deadly cruise ship outbreak.

"The CDC is conducting additional testing to confirm the resident is positive for Hantavirus," the health department shared in a news release. "It is believed the individual acquired the virus while cleaning a home where rodent droppings were present."

A confirmatory test result could take up to 10 days, CDC staff told IDPH.

What is it like in quarantine? Cruise passengers speak out

Jake Rosmarin, a Boston travel influencer and one of 18 American passengers aboard the MV Hondius cruise ship at the center of a deadly hantavirus outbreak, is speaking out about his time in quarantine. 

Rosmarin, who is currently asymptomatic, is at a quarantine center in Nebraska being monitored.

Out of concern for the safety of others, including his fiancé back home, he says he intends to quarantine in Nebraska for a full 42 days, the approximate incubation period of the virus.

"From the beginning, we were going to be given the option to stay for the full 42 days," he told USA TODAY. "I made that decision immediately, that I want to be here for that 42 days, because I know that if I'm here, I'm going to be in the best care possible, no matter what."

Contributing: Reuters and Charles Trepany, USA TODAY