Bacteremic urinary tract infection in older people

Abstract

Objectives: To describe patients with bacteremic urinary tract infections, compare characteristics of young and older patients, and suggest appropriate empiric antibiotic therapy for this clinical condition.

Design: Case series, with an observation period of 3 years.

Setting: A large southeastern community hospital.

Participants: One hundred eighty patients more than 18 years old (101 older than age 65) with urine and blood cultures simultaneously positive for bacterial organisms.

Measurements: Chart review-determined demographic characteristics, clinical data, bacterial organism and antibiotic susceptibility, number of medical diagnoses, use of a urinary catheter, admission source, and mortality.

Results: The 180 patients experienced bacteremias caused by 183 bacterial organisms. Sixty-one patients were aged 65 to 79 years, and 40 were 80 years of age or older; 63.9% of patients were female; 62.2% were black. Gram-negative organisms accounted for 80.3% of bacterial isolates, with Escherichia coli accounting for 54.1% of cases. Gram-positive organisms accounted for 19.7% of isolates, including Staphylococcus aureus (13.1%) and Enterococcus (5.5%). Older patients had a distribution of Gram-positive and Gram-negative organisms similar to that of younger patients. Men and patients with chronic urinary catheters had higher proportions of Gram-positive organisms and non-E. coli Gram-negative rods. Organisms showed excellent susceptibilities to commonly used antibiotics. In-hospital mortality was 16.1%, with higher mortality in patients with chronic urinary catheters, in patients who were admitted from nursing homes, and when a Gram-positive organism was identified. Advanced age was not associated with higher mortality.

Conclusions: Concomitant illness and especially the use of urethral catheters, but not advanced age itself, are associated with a higher mortality from bacteremic urinary tract infection. Single agent empiric antimicrobial therapy such as ceftriaxone may be appropriate in older patients with presumed urosepsis, except in catheterized patients or those with other risk factors for Gram-positive or resistant Gram-negative infections.