The first luxury cruise ship to dock in Portland this season has been hit by a norovirus outbreak that sickened more than 250 passengers, federal health officials confirmed Sunday.

The United States Center for Disease Control and Prevention (CDC) reports that 252 out of 919 passengers and eight out of 520 crewmembers aboard the Fred Olsen Cruises' ship Balmoral were struck with vomiting and diarrhea -- all symptoms of norovirus.

The month-long "Old England to New England" cruise contained two U.S. nationals, while the majority of the passengers were from the United Kingdom.

The ship's crew has stepped up cleaning and disinfection procedures while infected guests were asked to stay in quarters with complimentary room service and in-room entertainment.

An epidemiologist and two CDC health officers assessed the situation in Baltimore and gathered specimens. This incident was not the first case of gastrointestinal outbreak inside the vessel.

Six years ago, approximately 293 out of 1,163 passengers aboard the Balmoral on a world cruise from Dover were also struck with diarrhea and vomiting.

Meanwhile, Balmoral cruise ship passenger Robert Bruce of northern England told The Sun that the reports of the illness inside the ship spiked in the Azores on April 20, the fifth day since the cruise ship began sailing.

Fred Olsen Cruises has said in a statement that the company has been undertaking extensive sanitation measures and cleaning of the ship.

Norovirus is a stomach bug that is commonly reported when people are gathered in small areas, including restaurants, nursing homes, hospitals, cruise ships, and hotels.

The virus has been dubbed as the "winter vomiting bug" as it is more common in the winter but can also occur any time of the year.

The virus is the most common cause of food-borne diseases in the U.S., with outbreaks being reported in restaurants such as Chipotle Mexican Grill Inc. The CDC said more than 19 million cases of norovirus, with about 500 to 800 deaths, are reported in the country annually.

Illness from the norovirus commonly begins a day or two after being infected and abates within one or two days as well.

In the meantime, the ship and all the passengers have since left Portland, according to Robert Doherty, police lieutenant of the city's police department.

Photo: Gary Bembridge | Flickr