Norovirus Outbreak on Fred. Olsen Cruise Ship

An outbreak of the norovirus stomach bug has sickened 160 people aboard a Fred. Olsen Cruise Lines ship docked at Norfolk, Virginia, U.S. health officials and the company said on Friday.

The norovirus outbreak took place aboard the Britain-based line's Balmoral during a transatlantic cruise, the Centers for Disease Control and Prevention (CDC) said in a statement.

The CDC said 153 passengers and six crew members had fallen ill from norovirus, whose symptoms include vomiting and diarrhea.

The CDC said that the cruise line and the ship's crew had increased cleaning and disinfection and collected stool specimens. The company also sent a corporate sanitation manager to oversee handling of the outbreak.

CDC health officers and an epidemiologist plan to board the Balmoral when it arrives in Baltimore this weekend, the CDC said.

Fred. Olsen said in a statement that the vessel had docked at Norfolk and seven passengers were in isolation. Most of the passengers were from Britain, it said.

Norovirus is the most common cause of U.S. food-borne disease outbreaks. Infections usually occur in places such as hospitals, cruise ships and universities, where people eat and live in close quarters.

Two norovirus outbreaks were reported last year at the Massachusetts and California outlets of burrito chain operator Chipotle Mexican Grill Inc.

About 19 million to 21 million norovirus cases, with 570 to 800 related deaths, are reported in the United States each year, according to the CDC.