Forget the flu: Sydney vomiting bug is here

With the flu spreading across the U.S., it's easy to forget that there are other winter ailments attacking us this winter -- and there's a new one that could spread in a "severe" epidemic, according to researchers.

The Sydney vomiting bug, called so because the mutation was first identified in Australia, is a new variation on the norovirus, which is sometimes called the winter vomiting bug, Bloomberg reports. 

At particular risk may be the $40 billion cruise industry.

"Cruise ships are almost a sentinel sensing system for norovirus," University of New South Wales professor Peter White told Bloomberg. "Norovirus is going to wreak havoc in their cruise industry for the next year while this new strain gets a grip."

The virus has no vaccine and no specific treatment, and so far has killed nursing home residents across the globe. Because the Sydney vomiting bug is a combination of two different strains and mutated slightly, no one is immune, White said. 

Health-care facilities must be prepared for a "severe norovirus season" with the emergence of the new bug, researchers warned earlier this month. The disease causes a sudden onset of vomiting, and sometimes diarrhea, fever, headache and stomach cramps. It's particularly severe for people with weakened immune systems, as well as the very young and elderly.

At risk for coming in contact with the new bug are the estimated 10 million Americans who book cruises each year. Americans book more cruises than any other nationality, according to data from the Cruise Lines International Association, a trade group.

Cruise ships are giving passengers pre-boarding questionnaires about their recent health, the trade association tells MSN Money. "At this point, we are seeing a modest increase in gastrointestinal illness over the same period last year, which we understand mirrors the increased incidence on land," the group said. 

The norovirus has already hit some cruise lines this winter: Carnival Corp.'s (CCL) Queen Mary II underwent extra cleaning after an outbreak of the winter vomiting bug in December.

Incidences of norovirus on cruise ships are low, according to the Cruise Lines International Association's Website. It also notes that most outbreaks occur in "land-based settings such as schools, hospitals, and nursing homes." 

Cruise ships are susceptible to winter vomiting bug outbreaks because of their closed settings and regular changing of passengers, which allows the virus to infect new groups of people, wrote researchers at Center for Infectious Disease Control in the Netherlands in a 2008 study. 

"It’s almost impossible for them to protect themselves against a norovirus outbreak once it occurs," White told Bloomberg. "The only way you could do it would be to stay in your cabin the whole time and not go out."

More on Money Now

• Why Americans are buying more TVs
  
• Did GM just unveil the best sports car ever?
  
• More bad news for JC Penney