An outbreak of infection caused by trimethoprim-resistant coliform bacilli in a geriatric unit.

An outbreak of infections, particularly of the urinary tract, caused by coliform bacilli resistant to trimethoprim, and originating in a geriatric unit, is described. The investigation of the outbreak and the analysis of factors predisposing to asymptomatic carriage of trimethoprim-resistant coliform bacilli enabled successful control measures to be initiated. The significance of geriatric units as sources of hospital infection is discussed. The importance of cooperation between geriatricians, infection control nurses and microbiologists is emphasized.