Health officials and public health agencies across multiple countries are trying to identify and monitor people who may have been exposed to hantavirus following an outbreak on a cruise ship. Several reports say more than two dozen passengers disembark before the outbreak is detected, prompting efforts to locate them and assess their health. The response includes contacting passengers who left the ship before it was identified as carrying the virus and tracing potential close contacts they may have had after departure. One report describes similar efforts across U.S. states, where authorities are monitoring residents linked to the ship or otherwise exposed. Other outlets report that authorities have reached out to passengers from multiple countries, indicating the response involves international coordination. In the United States, at least some actions include quarantine orders for individuals connected to the ship, according to one report that cites CDC guidance. Overall, the monitoring and tracing focus on preventing further spread by following individuals who were on board or had close contact with infected passengers, as officials gather information about exposure timelines and symptoms.