The Queen Elizabeth 2 cruise liner made an unusual visit to the Bay Area in California before continuing on its 108-day scheduled cruise around the world. The cruise ship began it trip on January 8 from New York. After departing from Ft. Lauderdale, FL on January 10, more than 300 passengers and crew members aboard the ship fell ill with the norovirus, which is a highly contagious type of stomach flu.

By the time the ship reached the San Francisco Bay, only four passengers still had the viral symptoms, which include nausea, vomiting and diarrhea.

While the ship was in Acapulco, Mexico, officials from the Centers for Disease Control and Prevention boarded to help the crew with sanitation operations.

According to the CDC, most people recover quickly within 1 to 2 days of suffering from the virus. Health officials considered this outbreak to be unusually large, according to AP reports.

It is believed that noroviruses cause almost half of all food-borne illnesses in America, yet they are not considered to be as serious as similar bacterial infections such as E. coli and salmonella, reports the San Francisco Chronicle.

The Bay Area has reported many recent outbreaks, particularly reports of more than 300 cases in only eight facilities in which the outbreaks began to occur in the fall. County health officials had to quarantine many residents at one particular location. In one county, Sonoma County, three deaths occurred among the elderly that were also linked to the virus.