Two Americans who are not onboard a cruise ship tied to a reported global hantavirus outbreak are being monitored for symptoms, according to a report. The coverage says public health officials are tracking their condition as a precaution, reflecting uncertainty about how long it can take for symptoms of hantavirus to appear after exposure. The reporting also highlights that determining whether evacuated passengers become ill may take weeks, because symptoms may develop over an extended incubation period. Meanwhile, passengers who have been evacuated from the referenced cruise ship are also subject to monitoring protocols, though the exact duration and schedule of testing or observation are not specified in the provided text. Overall, the information presented centers on surveillance efforts for both individuals associated with the incident and broader concerns about the timeline for identifying cases and confirming whether people who were exposed go on to develop symptoms.