John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Disease-causing bacteria like MRSA and E. coli are remarkably good at surviving the in-flight environment.
Here's something to think about next time you reach for an in-flight magazine: That seat-back pocket, if left uncleaned, can harbor harmful pathogens for as long as a week after some contaminated person leaves them there.
That's one of the fun findings of an FAA-backed experiment carried out by scientists at Auburn University in Alabama and elsewhere. After obtaining samples of common cabin fixtures like the armrest and toilet-flush button, they smeared them with artificial sweat and saliva rife with either E. coli or methicillin-resistant Staphylococcus aureus (MRSA). Then they watched as the germs stubbornly refused to die, with MRSA lasting for 7 days in the seat pocket and E. coli for four days on the armrest.
The researchers call this the first step in understanding how diseases might live and spread throughout the cabin environment, which is typically marked by very low air humidity and crowded, elbow-jostling conditions. That last one is particularly relevant to the risk of spreading MRSA. Outbreaks of the notorious bacteria have often occurred in places that, like airplane cabins, are restricted and packed to the gills – think hospitals and prisons.
People who get sick with the strain of E. coli used in this particular research can suffer vomiting and bloody diarrhea. MRSA, meanwhile, can lead to nasty skin infections in a community setting and blood infections and pneumonia in medical ones. But not everybody knows they're carrying these pathogens, making their ability to cling to cabin surfaces all the more important.
"[MRSA] is being carried asymptomatically in a transient way by approximately 1 percent of the U.S. population," says Kiril Vaglenov, one of the Auburn scientists. "So there might be individuals in the airplane cabin without symptoms, but who are shedding the bacteria."
One bit of good news: Airline companies claim to be scrupulous about sanitizing their jets. United says via email that it "cleans and services each aircraft after every flight, and we perform deep cleanings according to our regular maintenance schedule of each aircraft type." Virgin writes that its planes "go through a 2-hour full overnight clean daily where all our seats are cleaned with a leather cleaner, the cabin gets a full vacuum, overhead bin doors, belt buckles, armrests, remote controls, tray tables, etc. are cleaned."
And Delta, which provided the samples used in the experiment, has a "robust" cleaning process before all departures and on aircraft that remain on the ground overnight, says company spokeswoman Lindsay McDuff. That includes restocking pillows and blankets, wiping down sinks and mirrors, disinfecting windows and tray tables, and vacuuming seat-back pockets.
For their next experiment, Vaglenov and his colleagues plan to examine the effect these cleaning protocols have on in-flight pathogens. They also want to investigate whether cabins could be sanitized further if airline companies were to use antimicrobial surfaces, such as ones enriched with copper or silver.
But for germaphobes worried about the present, there's one easy way to cut down on the risk of falling ill. "Just be self-conscious about hand hygiene," says Vaglenov, "and not traveling while you're contagious or sick."