[Urinary tract infections due to wide spectrum beta lactamase producing enterobacteriaceae]

The aim of this study was to specify the characteristics of enterobacterial urinary infections producing wide spectrum beta-lactamase (WSBL) and the management strategies for these patients infected in geriatric wards.

The prevalence, bacteriological characteristics and treatment regimens of enterobacterial urinary infections producing WSBL, diagnosed in a geriatric department of internal medicine from May 1977 to April 2001, were studied retrospectively.

Sixty-six enterobacterial urinary infections producing WSBL were diagnosed, with 53 (80%) of them acquired in the ward. They represented 1.6% of admissions and concerned 24 men and 42 women (sex ratio: 0.57), with a mean age of 87 years. Their prevalence was of 20 in the 1st year, 11 in the 2nd, 9 in the third and 26 in the 4th year. The mean duration of hospitalization of infected patients was 4.5-fold longer (90 vs. 20 days) and the mortality rate 2-fold higher (32 vs. 14%). Enterobacter aerogenes were responsible for half (46%) of the WSBL urinary infections. The skin was invaded by enterobacteria in 67% and the feces in 57% of cases. More than one third of the urinary infections treated relapsed, and digestive decontamination was only efficient in half of the patients treated.

This 4-year study emphasizes the limits of antibiotherapy in eradicating WSBL-producing enterobacteria and the fact that only the strict respect of hygiene by all caregivers (isolation of patients exhibiting WSBL and washing-disinfection of the hands between each patient) limits the incidence of such infections.