Several cruise lines have initiated active surveillance for respiratory illnesses, organized vaccination campaigns for crew members, and acquired stocks of influenza antiviral medications. Bur of Infectious Diseases, Office of Special Health Initiatives, Field Epidemiology Training Program, and Field Epidemiology Training Program officers, Laboratory Center for Disease Control, Occupational Health and Safety Agency, Health Canada. Often these travelers use some combination of buses, trains, airplanes, automobiles, and ships for transportation, and many travel as part of large organized groups. Large organized tour groups often include travelers from various regions of the world, including areas in which seasonal influenza is occurring, which potentially increases the risk for an off-season influenza outbreak among such tourist groups. In the influenza outbreak described in this report, cases of respiratory illness have occurred among tourists during different tours managed by different companies.
Preliminary evidence suggests that most illnesses appear to have developed during land-based travel.
However, cases of illness consistent with influenza transmission on board cruise ships are being reported in passengers and crew members. ARI and ILI cases that occurred before active surveillance was implemented probably have been substantially underreported. No special prevention measures are recommended for travelers who are aged less than 65 years and in good health. These travelers are unlikely to develop a febrile respiratory illness during their travels, and the risk for serious complications from influenza is low in this group. Early general vaccination of the resident populations in Alaska and the Yukon Territory also is not recommended at this time.