Around 158 passengers and 14 crew members have fallen ill onboard the Crown Princess cruise ship after the outbreak of a gastrointestinal ailment caused by norovirus, the US Centers for Disease Control and Prevention (CDC) has said.

The cruise ship, which is owned by Carnival Corporation, has docked at San Pedro, California, as per the schedule for its month-long voyage to Hawaii and Tahiti.

The vessel had been carrying a total of 3,009 passengers and 1,160 crew members.

In April, more than 100 people aboard the Crown Princess Cruise ship were ill due to the virus, Reuters reported.

"The ship began seeing an increased number of gastrointestinal illnesses, caused by norovirus." 

Company spokeswoman Susan Lomax was quoted by the news agency as saying: "Over the last few days, the ship began seeing an increased number of gastrointestinal illnesses, caused by norovirus."

"In response, we have enacted our stringent disinfecting protocols developed in conjunction [with CDC]."

According to the CDC, officials have started cleaning and disinfection procedures in-line with outbreak prevention and have also made announcements to notify onboard passengers of the outbreak, encourage case reporting and hand hygiene.

The collected stool specimens from ill passengers were found positive for the virus and are to be sent to CDC’s lab for further procedures.

A CDC vessel sanitation programme environmental health officer is expected to conduct an environmental health assessment and evaluate the outbreak and response activities.

Once disinfected, the Crown Princess ship is expected to depart for a cruise along the Mexican Riviera.