Maritime varicella illness and death reporting, U.S., 2010–2015

Abstract Background Ships destined for, or departing from, U.S. portsof entrymust report certain signs and symptoms of potentially communicable diseases of public health interest among travelers to the Division of Global Migration and Quarantine(DGMQ) at the Centers for Disease Control and Prevention. Methods We reviewed ships' varicella case and outbreak reports from January 2010 through December 2015. Results DGMQ received 967 reports of varicella and 13 reports of herpes zoster. Most varicella case-patients were 20–49 years of age (84.7%, 472/557) and were cruiseship crewmembers (78.4%, 758/967). Most often, cruiseship crewmember case-patients were born in or held passportsfrom Indonesia (21.7%, 80/369), Philippines (17.6%, 65/369), or India (17.3%, 64/369). Ninety-ninevaricella outbreaks were reported, including 439 varicella cases and one herpes zoster case; 97 (98.0%) outbreaks occurred on cruiseships, and 90.2% of associated cases were among crewmembers (397/440). Most varicella cases were in crewmembers, who are adults often from tropical regions where varicella immunity is acquired later in childhood or young adulthood or without varicella vaccinationprograms. Conclusion Varicella vaccinationas appropriate for susceptible travelers, particularly crewmembers, before maritime travel may decrease risk of varicella infection and prevent outbreaks on ships.