A Princess Cruises vessel docked Thursday night in a Houston-area port after more than 180 people became sick. It was the second cruise ship to return to its U.S. port this week after passengers and crew members contracted a suspected stomach illness. The other cruise, affiliated with Royal Caribbean, returned early to New Jersey on Wednesday.

Princess Cruises says it used labs on the ship to confirm passengers and crew members had contracted norovirus. Since more than 3 percent of those on board were affected, the company was required to alert the Centers for Disease Control and Prevention.

More than 160 people reported to the ship’s medical center, which has two doctors and four nurses, according to Princess Cruises. Those who became ill were asked to stay in their cabins to prevent the illness from spreading.

The company says it increased its sanitation efforts on the ship. After passengers left the vessel, the CDC boarded to oversee further sanitation of the ship, including cleaning all surfaces with a special liquid disinfectant.

Handling Illness

The CDC suggests ways that passengers can stay healthy on ships. They include: eat only food that is cooked and served hot, eat fresh fruit only if you have washed it and peeled it yourself, and make sure you’re updated on vaccines such as measles, mumps, rubella, varicella and flu.

Photo Credit: The Caribbean Princess in better times. Princess Cruises/Andy Newman / Associated Press