Norovirus Can Spread on Planes as Well as Cruise Ships
Researchers have connected a 2008 flight, where multiple passengers became sick, causing the plane to be diverted, to the highly contagious norovirus, the same infection that caused the return of three cruise ships in Charleston SC in recent months.
On October 8th, a flight out of Boston, carrying members of a tour group on their way home to Los Angeles, was landed in Chicago because of complaints of acute gastrointestinal illness, including vomiting and diarrhea. In Chicago, the tour group remained in the city overnight, several being hospitalized, while the remainder of the passengers boarded another plane to California. Seven of the passengers that were not part of the group later became ill.
The Centers for Disease Control and Prevention and the New Hampshire Department of Health later investigated the outbreak and found that 6 of the tour group and 1 of the non-tour group passengers were confirmed to have contracted norovirus. Fifteen others were considered “probable”, with six of those having just sat next to the ill patients on the flight from Boston to Chicago.
Noroviruses are a group of viruses responsible for more than half of all food borne gastroenteritis outbreaks.
Dr. Daniel Fishbein, the CDC researcher who led the investigation confirmed that the same strain of norovirus was recovered from stool samples in some of the passengers, confirming that the virus was transmitted on the airplane between passengers and was not likely present on the plane prior to the flight.
Sitting in an aisle seat or near a tour group member were strong risk factors for becoming ill, which suggests to investigators that transmission occurred either directly through person-to-person contact or indirectly via contamination of armrests, tray tables, or seat controls.
"This is the first time passenger-to-passenger transmission (of norovirus) has been documented on an airplane," said CDC epidemiologist Dr. Aron Hall. Only three other norovirus outbreaks on airplanes have been reported in the medical literature.
Unfortunately, a recent study from Laval University in Canada found that alcohol-based sanitizer products are among those that are ineffective against effectively eliminating norovirus. The only products that only bleach-based disinfectants reduced the concentration of norovirus on stainless steel surfaces by a factor of 1,000 while alcohol or quaternary ammonium based products were 100 times less effective.
The best protection from contagious viruses such as the norovirus on a flight, cruise ship, bus or other close quarters (think day cares, hotels, conventions, etc) is to practice good hygiene and wash hands with soap and water before and after such activities as using the restroom, preparing food, or touching common surfaces.
SOURCE: Clinical Infectious Diseases, May 1, 2010.