Asymptomatic bacteriuria in institutionalized elders in Israel

To document the prevalence of asymptomatic bacteriuria in patients in one large long-term care facility, and describe clinical outcomes in initially bacteriuric and nonbacteriuric residents during prospective observation encompassing one year.

Patients enrolled in the study were residents of the Haim-Shoham Geriatric Center, a long-term care institute with 800 inhabitants. Twenty patients were related randomly for study enrollment on each of the ten wards. A urine culture was obtained from the enrolled patients. A second culture was obtained within one week if the initial culture grew >or= 10(5) colony-forming units per milliliter (cfu/ml) of at least one uropathogen. Demographic data and comorbidities, as well as most recent laboratory results, were recorded for all patients enrolled. Subjects were followed prospectively for one year or until death. Clinical events and usage of antibiotics were recorded. In patients with asymptomatic bacteriuria, repeated urine cultures were obtained every two months.

Eighty-five (43.3%) of a total of 196 elder residents screened presented asymptomatic bacteriuria. There were no differences between patients with and without asymptomatic bacteriuria in age, gender, and underlying diseases. Patients with asymptomatic bacteriuria were significantly more bed-ridden (91.7% vs. 82.1%, P = 0.05); demented (78.8% vs. 59.8%, P = 0.03); and incontinent of urine (93% vs. 71.4%, P < 0.0001) and bowel (85.8% vs. 59.3%). During one year of prospective observation, bacteriuric patients had a mortality rate of 25.9%, compared to 7.1% for nonbacteriuric (P < 0.0001). Mortality in the group with bacteriuria was higher due to both urinary infection and other causes.

In our population, asymptomatic bacteriuria was associated with increased functional impairment and increased mortality over 12 months. The increased mortality, however, was not fully attributable to urinary infection.