A group of Americans evacuated from a cruise ship tied to a rare and deadly hantavirus outbreak will be monitored for up to 42 days upon arrival in the United States. The extended monitoring period reflects the unusually long incubation window associated with the Andes strain of the virus.
Most passengers are being monitored at the University of Nebraska Medical Center’s Regional Emerging Special Pathogen Treatment Center in Omaha. Two others, including one passenger with mild symptoms who traveled in a biocontainment unit, were transferred to Emory University Hospital in Atlanta, officials said.
Officials at Nebraska Medicine said passengers could eventually complete part of the 42-day monitoring period at home, as officials emphasized that passengers are not under mandatory quarantine but are undergoing medical assessment and monitoring. Symptoms can take up to 42 days to appear after exposure.
“Passengers' monitoring location will be based on their access to healthcare, home environment, comorbidities, ability to follow public health directions, and ability to perform essential daily tasks,” states the CDC.
The monitoring period is significantly longer than isolation timelines used during the COVID-19 pandemic. The CDC previously estimated COVID-19 symptoms generally appeared within two to 14 days after exposure, with an average incubation period of about three to six days.
By contrast, Andes virus infections can emerge between four and 42 days after exposure, according to CDC guidance. The CDC also said the risk to the U.S. public remains low.
The outbreak aboard the Dutch-operated expedition cruise ship was first reported on May 2 while the vessel traveled in the Atlantic Ocean near Spain’s Canary Islands.
The World Health Organization (WHO) confirmed the outbreak involved the Andes virus, which can cause hantavirus pulmonary syndrome, a severe respiratory illness.
According to the CDC, hantaviruses are typically spread through exposure to infected rodents, especially their urine, droppings, or saliva.
Andes virus is the only hantavirus strain known to spread between people, usually through prolonged close contact involving respiratory secretions or bodily fluids.
The WHO said eight confirmed infections have been identified among former passengers, and three deaths have been reported involving a Dutch couple and a German national.
Spanish authorities continued evacuation operations Monday for passengers still aboard the ship near Tenerife.
The CDC said it respects people's rights to make decisions about their own medical care if they choose to refuse treatment.
“We are committed to working with anyone who has concerns and providing information need to make informed decisions about their care,” the CDC said. “At the same time, CDC has a responsibility to protect the public's health, and we are working closely with state and federal partners to ensure that all passengers receive appropriate monitoring during the incubation period."