Norovirus Cleaning Begins at Dulles Hotel

The Virginia Department of Health has reported 52 norovirus outbreaks -- which account for many more individual cases -- this winter, according to the most recent data available. Last month, dozens of Catholic University students fell ill with norovirus. Far from Washington, there was an outbreak on the Queen Elizabeth 2 during a voyage from England to New York.

In Maryland, 34 gastroenteritis outbreaks have been reported this year, state health officials said. Ten appear to be caused by norovirus, and test results are pending in the other instances.

A District health spokesman said last month's outbreak at Catholic University was the only large norovirus incident reported in recent years.

At the Hilton, guests first began reporting symptoms Tuesday night, and some suspected food poisoning, Cree said. The hotel contacted the Fairfax County Health Department, and scientists examined the restaurant and kitchen and collected stool samples from people who were ill. Tests on those samples confirmed norovirus as the culprit.

Hilton officials found reservations at other hotels for guests checking in mid-week and through the weekend and moved a gala and other events. Employees will return to work Monday, and the hotel is scheduled to reopen at noon Tuesday.

The Hilton isn't the only area hotel that has been forced to close because of the virus. In 2003, dozens of guests and visitors at the nearby Hyatt Dulles fell ill. The hotel reopened after three days of top-to-bottom cleaning.

Lucy Caldwell, a Virginia Department of Health spokeswoman, said the best way to avoid the misery of norovirus is frequent hand-washing. If you do become ill, disinfect everything you've touched. "Spend time cleaning the toilet, including the handle," Caldwell said. "Clean anything you touch. The soap dish, your phone, the remote control."

Norovirus is almost always passed through vomitus or feces. Perhaps as few as 10 virions -- individual virus particles -- are enough to cause infection. The incubation period is usually a day or more. Three-quarters of people report vomiting and diarrhea, although only one-third have fever, and symptoms usually last about five days.

About 20 percent of whites appear to be genetically resistant to one strain of norovirus, called Norwalk virus. Death from the infection is uncommon, but it can occur in the debilitated elderly.

Norovirus has been responsible for several large, dramatic outbreaks that illustrate its extreme contagiousness and persistence.

Early this decade, 660 patrons of a restaurant in Nagasaki, Japan, became infected with norovirus. Boiled broccoli that had been handled with bare hands after cooking was the most likely source of infection.

Contaminated drinking water, and even insufficiently chlorinated swimming pools, have caused outbreaks of norovirus infection.

Staff writer Susan Levine contributed to this report.