There are no confirmed hantavirus cases in the US from the Andes outbreak that killed three on a luxury cruise ship.
41 people, including 18 quarantined in Nebraska and Atlanta, are being monitored for infection.
CDC advises most to stay home for six weeks and avoid contact.
One patient initially in biocontainment at Nebraska Medical Center has moved to quarantine.
CDC says no cases domestically, with more test results pending.
