Acknowledgement to Ironshore Environmental
By David Brown and Maria Glod
Washington Post Staff Writers
Saturday, January 20, 2007
The Hilton Washington Dulles Airport hotel closed yesterday for the weekend so crews could scrub and sanitize every surface after about 120 employees and guests were sickened by the highly contagious norovirus, which officials say is particularly severe this year.
As the last guests filtered out early in the afternoon, workers from a professional cleaning company prepared to scrub every nightstand and counter twice with a chlorine bleach solution. The crew will also clean carpets and drapes and mist each room with a disinfectant.
“It’s a floor-by-floor, room-by-room, surface-by-surface process,” said Jim Cree, the hotel’s director of sales and marketing, who was washing his hands more than hourly yesterday to avoid the bug. “This will be the most sanitized building in the country.”
This season is shaping up to be a particularly severe one for the illness sometimes known as “winter vomiting disease,” said an expert at the federal Centers for Disease Control and Prevention, which helps track some of the 23 million cases of norovirus infection that occur each year.
First identified in 1972 but only routinely tested for in the past decade, norovirus is perfectly suited for causing dramatic outbreaks in crowded settings, including cruise ships, hospitals, nursing homes and hotels.
Even a very small amount of the virus can cause infection. It survives prolonged periods on such surfaces as counters and door handles, and it can become airborne under some circumstances. Some common disinfectants — such as alcohol-based waterless hand scrubs — won’t kill it.
The chief mystery about the microbe, to both scientists and the public, is whether norovirus infections are becoming more common or just better publicized.
“That is the key question, and I don’t think we really have an answer to it,” said Robert L. Atmar, a norovirus researcher at Baylor College of Medicine in Houston.
“We certainly have better tools to diagnose the infection now, and they are being applied more frequently. That said, it seems that in the last year, there has been an increase in the number of norovirus outbreaks that have been reported,” he said.
Marc-Alain Widdowson, a medical epidemiologist at CDC, said that “this winter season seems to be worse than previous winter seasons. The last time we had things this bad was 2002-03.”
The severity of outbreaks may vary year to year, as is the case with influenza, even if the long-term incidence is not rising, he said.
Current estimates are that at least half of the more than 75 million annual cases of food-borne illness in the United States are caused by norovirus. About 20 percent of people who go to a doctor because of acute diarrhea are infected with it. The virus is believed to cause 10 times as many cases of diarrhea-and-vomiting illness as the next-most commonly implicated microbe.
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.