SAN FRANCISCO >> The Centers for Disease Control and Prevention is investigating an outbreak on a Hawaii-bound luxury cruise ship where more than 150 people have reported gastrointestinal illness, including diarrhea and vomiting.

The Queen Victoria, operated by Cunard Cruise Line, departed San Francisco today on its way from Florida to Hawaii. The ship is carrying 1,800 passengers and 970 crew members.

The cause is unknown. Cunard told the CDC that the ship increased cleaning and disinfection, and isolated ill passengers and crew.

In a news release this evening, the Hawaii Department of Health said it is closely monitoring the reported outbreak on the ship, which is set to dock in Honolulu next week.

“The cause of the illness has not been confirmed at this time, but the symptoms and spread appear to be similar to norovirus,” health officials said in a statement.

The reported cases are totals for the entire voyage and do not represent how many people are actively sick at any one time, the CDC said.

The company did not immediately respond to an email from The Associated Press seeking more details.

The ship originated in Germany Jan. 9 and departed Florida Jan. 22, according to ship tracker Cruise Mapper. Its next stop is Honolulu on Feb. 12 and ends in Australia next month.