Nosocomial infection of the urinary tract.

Urinary tract infections appear to be responsible for 35 percent of all hospital-acquired infections, occurring in approximately two patients per 100 admissions. The great majority of infections are associated with urinary tract instrumentation. Female sex, advanced age and debilitating underlying illness appear to be associated with an increased risk of infection, but other risk factors have been poorly defined and case-control studies assessing excess morbidity and mortality associated with nosocomial bacteriuria have not been made. In most instances, the hospitalized patients are the reservoirs for the etiologic organisms, but cross-infection from other infected patients also occurs. Current preventive efforts have been primarily directed at aseptic catheter care techniques and reducing catheter use. Further developments in our prevention and control of these infections require an understanding of the mechanisms responsible for colonization of the urethra and bladder with gram-negative organisms and ways to discriminate patients at special risk.