More Americans Being Monitored for Hantavirus Than Previously Known

The number of Americans being monitored after potential hantavirus exposure has climbed to 41, but there are no current U.S. cases, the CDC said on Thursday.

That tally is up from earlier reviews of state health department data, which showed that at least 36 people in 11 states were under monitoring for potential exposures in connection with the cruise ship outbreak linked to 11 cases and three deaths worldwide.

David Fitter, MD, the CDC’s incident manager for the hantavirus response, defended the agency’s response to the outbreak in a media briefing on Thursday and emphasized that the CDC is working closely with health authorities here and abroad.

“We understand how to respond to [hantavirus] and remain vigilant,” he said. “We’re working very closely with all the state and local health departments to monitor everybody, all the contacts that are coming back again.”

Fitter noted that the current risk to the general public is low. Testing for hantavirus is recommended only for people with symptoms, and ongoing testing decisions by health authorities “are guided by the best available evidence.”

The 41 people currently undergoing the 42-day symptom-monitoring period includes three main groups:

• Passengers from the cruise ship who’ve returned to the U.S. and are undergoing monitoring at the University of Nebraska Medical Center in Omaha or Emory University in Atlanta
• Passengers who left the ship and returned home before the outbreak was identified
• People who were potentially exposed during travel on flights with ship passengers who disembarked before the ship reached the Canary Islands

“We want to ensure that a good plan is in place for the passengers and for the jurisdictions to ensure everyone remains safe and healthy, and that all communities also remain safe and healthy,” Fitter said.

The CDC has been criticized for its slow response to the outbreak. It wasn’t an agency announcement that brought news of the American passengers who returned home from the cruise ship after the first fatality — but before the outbreak was identified — but rather MedPage Today‘s own reporting on May 6. The agency 2 days later issued a health advisory that urged clinicians to be aware of the potential for imported hantavirus cases connected with the cruise ship outbreak.

The CDC has 100 staff members as part of their response but isn’t using its federal quarantining authority on any passengers or potential contacts, Fitter said, choosing instead to work “closely with passengers and public health partners to ensure monitoring and rapid access to care if symptoms develop.”

Interim guidance for monitoring and managing potential exposures from the agency stratifies contacts into high- and low-risk categories. High-risk contacts who were aboard the cruise ship should choose home- or facility-based management with isolation and travel restrictions. Low-risk contacts who had limited exposure to symptomatic people should self-monitor for symptoms for 42 days, but there are no recommended travel or activity restrictions.

While appropriate monitoring can happen in home-based settings, Fitter noted, the CDC has encouraged the 16 people being monitored at the University of Nebraska Medical Center to remain at the center. If hantavirus symptoms develop, he added, the CDC can turn around testing in 24 hours.

Fitter deferred questions about current test results among the 41 people under monitoring to state and local authorities, in addition to questions about whether states had agreed with the CDC’s recommendation that some high-risk people could move from facility- to home-based management.

The number of people being monitored could rise if health authorities broaden their search for exposed individuals’ contacts. “We’re … monitoring all Americans who potentially would have been exposed, whether in the U.S. or abroad, and we have been in contact with them,” Fitter explained.