It's that time of year: Princess Cruises announced that 284 passengers and 34 crew members became ill with vomiting and diarrhea on a cruise that returned Sunday to Galveston, Texas, after visiting the Caribbean and Mexico. The Ruby Princess had a total of 2,881 people on board, including 1,159 crew members, the Hill reports. The ship underwent "additional disinfection" before heading off on another cruise, which is still underway, that same day. Passengers on the current cruise were informed about the outbreak. The cruise line says it's "likely" norovirus is to blame, but the cause of the illnesses has not yet been officially identified.
"At the first sign of an increase in the numbers of passengers reporting to the medical center with gastrointestinal illness, we immediately initiated additional enhanced sanitization procedures to interrupt the person-to-person spread of this virus," a Princess rep says. Norovirus, often referred to as the "stomach flu," is highly contagious, causes vomiting and diarrhea, and is responsible for more than 90% of diarrheal disease outbreaks on cruise ships, CBS News reports. However, less than 1% of all reported norovirus outbreaks come from cruise ships; the vast majority are reported in long-term care facilities and hospitals, or are linked to restaurants or catered events. (Read more Princess Cruise stories.)