CDC: 172 people on Crown Princess cruise fell ill with norovirus

SAN PEDRO, Calif. -- A norovirus outbreak struck the Crown Princess during a month-long Pacific cruise. At least 172 people fell ill with the highly contagious stomach virus, according to the Centers for Disease Control and Prevention.

The ship will return to the port of San Pedro Sunday. It set off from Papeete, Tahiti to Los Angeles on Oct. 18. According to the CDC, 158 of 3,009 passengers were sickened with norovirus, while 14 of 1,160 crew members were affected.

In a statement, Princess Cruises said the ship would "increase cleaning and disinfection procedures according to their outbreak prevention and response plan." An all-out effort is underway to sanitize the ship to further prevent the spread of any germs.

A CDC Vessel Sanitation Program environmental health officer was expected to board the ship Sunday to conduct a health assessment and evaluate the outbreak and response activities.

"We are sorry this incident has impacted our guests' vacations and are grateful for their understanding given the circumstances. The health and safety of our crew and guests is our top priority," Princess Cruises said.

The norovirus, which has been a recurring problem for the cruise industry, causes flu-like symptoms including nausea, vomiting, diarrhea and stomach cramping. The virus can be transmitted from an infected person, contaminated food or water, or by touching contaminated surfaces.

In April, 129 people on the same ship contracted norovirus during a seven-day cruise off the California coast.

Most people who contract norovirus get better within one to three days.