Oropharyngeal and gastrointestinal carriage in the critically ill.

Enterobacterial and pseudomonal carriage in the oropharynx, stomach and gut is uncommon in healthy individuals (apart from E. coli in the gut). Underlying intrinsic disease is the main cause of oropharyngeal and gastrointestinal carriage of 'abnormal' flora. Interventions including intubation, catheterisation and drugs impairing peristalsis may promote this abnormal carriage in the critically ill. The oropharyngeal and gastrointestinal carrier state is the first stage in the development of nosocomial infections. Procedures aimed at the prevention of hospital infections via the abolition of the abnormal carrier state are termed selective decontamination techniques.