Controlling multiple-drug-resistant organisms at the hospital level.

Nosocomial infections due to multiple-drug-resistant (MDR) organisms are associated with poor patient outcomes and increased healthcare cost. The natural history of an MDR nosocomial infection can be characterised in four steps. First is the introduction of MDR organisms into the patient's normal flora as a consequence of inappropriate infection control practices. Second is the selection of MDR organisms due, in part, to inappropriate antibiotic therapy. Third is the development of an MDR infection due, in part, to inappropriate invasive techniques. The fourth step occurs when the patient has developed poor clinical outcomes due, in part, to inappropriate antibiotic therapy. At the local hospital level, a multidisciplinary MDR control programme should be developed with the goals to optimise local surveillance of MDR organisms, improve local infection-control practices, and control local antimicrobial use. Without achieving these three goals, hospitals will not be able to control the spread of MDR organisms.