JUNEAU -- Three Alaska cruises have had norovirus outbreaks this year.

Federal health officials tell CoastAlaska that's more than usual, but not a cause for alarm.

The latest outbreak came on the Sea Princess, which sails 10-day tours from San Francisco to southeast Alaska ports.

About 140 people became ill on two different cruises, one ending May 30 and the other June 9.

The Centers for Disease Control says 113 cases of norovirus were reported on the May 20 cruise of Celebrity Millennium.

Norovirus, a common gastrointestinal illness, causes diarrhea and vomiting.