More than 200 passengers on a Royal Caribbean cruise ship and several crew members took ill with a stomach virus during a seven-day cruise.

Royal Caribbean International said 243 of 3,252 passengers on board the Explorer of the Seas had caught a norovirus, a common cause of infectious gastroenteritis prevalent in hospitals, nursing homes, cruise ships and other semi-enclosed environments. All those affected were treated

A new study finds diarrheal disease cases in cruise ship passengers increased during 2001 through 2004, despite good results from environmental health sanitation inspection of the ships.Researchers led by Elaine H. Cramer, M.D., analyzed cases of gastroenteritis reported on cruise ships calling on U.S. ports for a four-year period.

The results showed gastroenteritis outbreaks per 1,000 cruises increased overall from 0.65 in 2001 to 5.46 in 2004. At the same time, ship environmental inspection scores were high, with an average of 95 on a 100-point scale

Federal officials approve a new vaccine by New Jersey-based Merck that protects infants from rotavirus. The disease causes diarrhea and dehydration and leads to hundreds of thousands of deaths a year in developing countries.

In the U.S., more than 70,000 children are hospitalized each year because of the infection.But in trials, RotaTeq prevented at least 98 percent of severe cases of gastroenteritis, or intestinal inflammation. It was tested on 60-thousand babies

Researchers have found one in every ten imported oysters screened in Hong Kong showed signs of norovirus, the term for the Norwalk-like virus that causes severe diarrhea and vomiting.

Senior investigator Dr. Wilina W. L. Lim notes outbreaks of gastric illness caused by norovirus are often linked to eating tainted oysters, making contamination fairly widespread