The Halifax Port Authority is preparing for the arrival of a cruise ship carrying more than 200 passengers who have been sick with the norovirus.

The Balmoral, a U.K. cruise ship, has 919 passengers, of whom 252 show symptoms of the disease, according to the U.S. Centers for Disease Control and Prevention. The ship left Saint John on Monday and should dock in Halifax at 8 a.m. on Wednesday.

Lane Farguson, a spokesman with the Halifax Port Authority, said they're following the situation.

"We're working with the cruise line to provide additional cleaning of all of those surface areas that people would normally touch," he said. "That would include railings and door handles, washrooms."

Cleaning to continue

They'll keep up the cleaning of the ship and the port throughout the ship's stay. It's set to leave Halifax at 5 p.m. or 6 p.m. Wednesday.

Norovirus is a gastrointestinal virus that causes vomiting, diarrhea, cramps, weakness and chills. Symptoms can develop within 12 hours of exposure and sometimes also cause a low-grade fever, headache, muscle aches and fatigue.

Most sick passengers have recovered from their symptoms, the owner of the vessel said Tuesday.

A spokeswoman with Fred Olsen Cruise Lines said seven passengers have been asked to stay in their cabins, out of 1,434 passengers and crew on board the Balmoral.

Rachael Jackson said the remaining passengers who became sick are feeling better and are no longer sequestered to their rooms.

"The rest have recovered from their symptoms and been released," she said, adding that the majority of passengers are British. "At no point has Balmoral been quarantined in any port on this cruise, and is continuing as planned."

Jackson says officials have increased cleaning and disinfection procedures, begun collecting stool samples for testing and sent a public health and sanitation manager to oversee the outbreak response.

She said the ship was inspected by the CDC, coast guard and Canadian Port Health, saying it received a US Public Health score of 91 per cent.

After a 1-day stop in Saint John, a cruise ship with 200+ passengers with Norwalk virus is headed for Halifax. <a href="https://t.co/36sNjJhUES">pic.twitter.com/36sNjJhUES</a> —@Brett_CBC

'A routine occurrence'

The Public Health Agency of Canada is monitoring "elevated gastrointestinal illness rates" aboard the Balmoral, Port Saint John said in a statement last week.

The health agency "is working in collaboration with the cruise ship operator to investigate the nature of the illness reported and mitigate the risk to other passengers or crew by ensuring that the vessel has implemented their outbreak prevention procedures," the statement said.

Gastrointestinal illnesses on cruise ships are "a routine occurrence and there is low public health risk," according to the statement. Among the general public, norovirus is second only to the common cold in rates of prevalence, it states.

Found in stool and vomit

Noroviruses are very contagious and can spread easily through direct contact with an infected person, by touching contaminated surfaces or objects, or by consuming contaminated food or water, according to the Public Health Agency of Canada's website.

The viruses are found in the stool and vomit of infected people.

People normally recover within one or two days, but can remain contagious for up to two weeks, according to the health agency. Good hygiene practices, including frequent handwashing, is advised.

The Fred Olsen Cruise Lines ship left England for a 34-day cruise taking in Boston, Portland, Saint John and Halifax.