Hantavirus live updates: CDC alerts US doctors to be aware of potential for imported hantavirus cases

The California Health Department says they are monitoring one former passenger of the cruise ship M/V Hondius for potential hantavirus infection.

"Local health officials are in contact with the one returned passenger," the department said in a news release. "At this time, public health protocol includes daily temperature checks and assessment for any symptoms consistent with hantavirus, and direction to modify activities."

The department said it was notified by federal officials that a second California resident is still on board the cruise ship.

There are at least nine U.S. residents under monitoring across six states

No U.S. residents under monitoring have shown any signs of illness at this time.

The Centers for Disease Control and Prevention said it deployed a team earlier Friday to the Canary Islands, where the M/V Hondius is expected to dock in the coming days.

"The team will conduct an exposure risk assessment for each American passenger and provide recommendations for the level of monitoring required," the CDC said in a statement.

The American passengers will be evacuated on a U.S. government medical repatriation flight to Nebraska and transported to a quarantine center at the University of Nebraska in Omaha, the CDC said.

Another CDC team will deploy to Offutt Air Force Base in Bellevue, Nebraska, to "support public health assessment of returning passengers," the agency said.

Oceanwide Expeditions provided an update about the 87 guests and 60 crew member aboard the M/V Hondius Friday and said the situation on board "remains calm," as it heads to the Canary Islands.

The boat is scheduled to arrive early Sunday, but that timetable is subject to change, according to Oceanwide.

"Preparations regarding our point of arrival, quarantine and screening procedures for all guests, and the onward travel plans for all guests and affected crew are being led by organizations from a number of countries, including the WHO, RIVM, and Dutch authorities, in close cooperation with Spanish government authorities," Oceanwide said in a statement.

The cruise company provided a breakdown of the ship's passengers and crew and revealed there are 17 Americans aboard the ship.

-ABC News' Claire Bower

Several American passengers from the cruise ship associated with a suspected hantavirus cluster are set to arrive at a quarantine unit in Nebraska over the next few days. Here's what to know about the facility.

The National Quarantine Unit, managed by Nebraska Medicine and the University of Nebraska Medical Center (UNMC), is the only federally funded quarantine unit in the U.S.

Its 20 single-occupancy rooms with en-suite bathrooms contain individual negative air pressure systems to safely house individuals exposed to highly hazardous communicable diseases, according to Nebraska Medicine and UNMC.

The rooms also contain exercise equipment and WiFi connectivity for patients requiring longer stays.

Nebraska Medicine and UNMC also manage the Nebraska Biocontainment Unit (NBU), which provides medical care to patients with highly hazardous communicable diseases.

“Unit personnel consists of a voluntary staff of select physicians, nursing, nursing assistants and respiratory therapists specially trained in high-level isolation and bio preparedness,” Nebraska Medicine and UNMC said on its website.

The NBU was activated in 2014 to care for U.S. citizens affected by the Ebola outbreak and medically evacuated from Africa and during the COVID-19 pandemic in 2020 to care for U.S. citizens from Wuhan, China, and the Diamond Princess Cruise ship.