Norovirus outbreak - About 172 people aboard a cruise ship which docked in California on Sunday are said to be infected with the highly contagious norovirus.

According to the Centers for Disease Control and Prevention, out of the 3,000+ passengers aboard the Crown Princess, about 158 have fallen ill with the virus. Also, 14 crew members out of the 1,160 aboard the vessel have been infected in the latest norovirus outbreak.

"Over the last few days, the ship began seeing an increased number of gastrointestinal illnesses, caused by norovirus (commonly referred to as stomach flu)" Princess spokeswoman Susan Lomax said.

The Crown Princess, which was on a month-long trip from Los Angeles to Hawaii and Tahiti, is reportedly being disinfected according to the stringent measures issued by the CDC. The ill passengers are also being treated aboard the ship.

CDC officials are expected to inspect the cruise, in which the norovirus outbreak occurred, when they arrive in San Pedro. Meanwhile, an investigation into what may have caused the norovirus outbreak is underway.

Lomax said that the Crown Princess is scheduled to undergo deep cleansing at the Los Angeles terminal before setting out on its next voyage through the Mexican Rivera.

This is not the first time passengers of the Crown Princess have been plagued by a norovirus outbreak. In April, over a 100 people - including passengers and crew members - were confirmed to have been infected with the virus while the ship was on a seven-day cruise off the coast of California. Management of the cruise ship reportedly used the same CDC-prescribed method to disinfect the vessel after that incident.

"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.

The recurrent norovirus outbreak, which reportedly infects millions of people yearly, is caused by fecal contaminated water and food. The virus can also be spread from person to person as well as through aerosolization and contaminated surfaces.

Luckily, it is easy to identify and contain a norovirus outbreak. The symptoms of the virus include vomiting, diarrhea, body aches, fever, weakness and abdominal pains. According to the CDC, most people suffering from the virus recover within three days.