About 220 passengers aboard the Norwegian Cruise Lines ship, Pride of Hawaii, fell ill because of a highly contagious Norwalk virus. The norovirus caused stomach flu, nausea, vomiting and diarrhea in passengers after they returned Monday to Honolulu following a seven-day cruise around the islands.

Janice Okubo, spokeswoman for the Hawaii Department of Health said, "It's one of the common viruses we've been seeing on cruise lines. Most of the time, people recover."

The Norwalk-like virus infected about 9 percent of the ship's 2,500 passengers. However, none of the sick passengers were hospitalized and they were asked to remain in their cabins for 24 hours in order to quarantine the virus. Virus symptoms typically last a day.

Sick passengers were also given a $200 credit to use while aboard the ship, the cruise line said. The ship surfaces underwent intensive cleaning to eliminate lingering contaminants.

The U.S. Food and Drug Administration (FDA) will investigate the outbreak on one of the largest and most expensive U.S.-flagged cruise ships ever built.