LOS ANGELES — A nearly monthlong cruise that saw more than 170 passengers get sick with the gastrointestinal illness norovirus has ended in Los Angeles with a thorough cleaning of the ship.

Carnival's Crown Princess docked Sunday at the Port of Los Angeles after the voyage that took more than 4,100 people from Los Angeles to Hawaii to Tahiti and back.

Passengers who disembarked said the crew took extra steps to stem the outbreak.

"In the dining rooms you were no longer allowed to take your utensils. Everything was handed to you. ... They had to serve you the food. And so those measures really, I think, reduced the number. It could have been far worse," said Yvonne Lubos told KABC-TV.

"We encouraged our children to do an extra good job washing their hands, and we did as well, but it didn't impede our enjoyment of the cruise at all," said Laura Tagliere.

In April, 129 people on the same ship contracted norovirus during a seven-day cruise off the California coast. The vessel went through a stringent disinfecting process after both cruises.

After it docked Sunday, an official with the Centers for Disease Control and Prevention boarded to investigate the outbreak and the cruise line's response.

The ship underwent a deep cleaning at a terminal in San Pedro before embarking on its next voyage to the Mexican Riviera, company spokeswoman Susan Lomax said.

"As it is the cold and flu season, when the stomach flu circulates on land, we encourage all of our guests to be diligent in following the widely accepted practices of frequent hand washing with soap and water and the use of hand sanitizers," Lomax said.

Symptoms of norovirus include vomiting, diarrhea, fever and body aches. According to the CDC, most people recover within three days.