To and Fro and In-between (or Ew! I don't want to touch it!)

This is the second installment of the series "To and Fro and In-between" covering getting sick while traveling in an airplane.  Last week's installment was getting sick through breathing the same air as that coughing passenger.  This week is about what you can catch through touch, or direct contact transmission.

Kiril Vaglenov of Auburn University recently presented to the the American Society of Microbiology his research regarding the lifespan of certain bacteria on airplane cabin surfaces.  He and his colleagues tested the ability of two pathogens, MRSA (methicillin-resistant Staphylococcus aureus) and E. coli 0157:H7 (Escherichia coli) on common surfaces in airplanes.  Materials for the armrest, plastic tray table, metal toilet button, window shades, seat pocket cloth, and leather were inoculated with the bacteria and exposed to typical airline conditions.  MRSA lasted 168 hours on the seat-back pocket while E. coli O157:H7 survived 96 hours on the armrest material.  Current cleaning practices of aircraft according to the World Health Organization include cleaning the aircraft interior as time permits, with priority given to litter and dry waste removal and cleaning of the toilet compartments and galleys.

E. coli O157:H7
Image courtesy of CDC

E. coli is a large and diverse group of bacteria.  Most strains are harmless, and some even live in human and animal intestinal tracts.  However, the O157:H7 strain is considered pathogenic because it produces a toxin called Shiga, causing stomach cramps diarrhea that is often bloody, vomiting, and possible low grade fever.  It is transmitted through contaminated water or food, and is the strand that is most common in North America during E. coli "outbreaks" of infections.

MRSA bacteria
Image courtesy of CDC

MRSA stands for methicillin resistant Staphyloccous aureus, a type of staph bacteria that is resistant to several antibiotics.  MRSA can cause skin and other infections, as well as severe problems in healthcare settings such as bloodstream infections, pneumonia, and surgical site infections.  It is spread though direct contact with an infected wound or sharing personal items that have touched skin.  Infection risk can be increased by certain activities or places that include crowding, skin-to-skin contact, and shared equipment or supplies. Symptoms begin as a bump or infect area that might be red, swollen, painful, warm to the touch, full of pus or other drainage, and may be accompanied by a fever.  Two in every 100 people are MRSA colonizers, meaning they carry it as part of their natural bacteria.

Further research into direct contact transmission on airplanes is going to involve testing other human pathogens including those that cause tuberculosis, as well as exploration of effective cleaning and disinfection strategies.  Different surfaces that have antimicrobial properties will be tested to see if they will reduce the persistence of pathogenic bacteria in the cabin.

Until more is known about what can spread by just touching the armrest, avoid touching your face during the flight and wash your hands before eating (and don't eat the food that fell on the tray table).

Source: American Society for Microbiology