Several recent outbreaks of infection occurring in American hospitals have been caused by inadequately sterilized flexible fiber optic endoscopes and brocho scopes, according to The Centres for Disease Control.
These tubes are passed through a bodily orifice in order to inspect the inside of the body cavity, usually the stomach or, in the case of bronchoscope, the lungs.
Thee devices are cleaned and disinfected either manually, which is time consuming for a busy hospital, or increasingly, by automated machines.
After investigating an outbreak of Pseudomonas aeruginosa, causing infection of the gallbladder, which occurred in a Wisconsin Hospital, the CDC found the culprit to be a thick film of P Aeruginosa which had formed in the detergent holding tank, water hose and air vents of the automated disinfecting machine.
"Attempts to disinfect the machine by the manu facturer's instructions using commercial prepar ations of glutaraldehyde were unsuccessful," said a report in the Journal of the American Medical Association.
A similar situation occurred with another hospital in Missouri.
The Food and Drug Administration requested that one of the manufacturers send out a safety alert to all hospitals with its products, recommending that a stringent rinsing programme be adopted for the cleaning of the machines.
The FDA also has suspended the further sale of any of the machines until the contaminiation problem is resolved. For the moment, it requests that hospitals report any further problems of infection.
Endoscopes have been implicated in cases of hepatitis B infection, among others.