Dimitri M. Drekonja, MD, MS, Staff Physician, Minneapolis Veterans Affairs Medical Center; Assistant Professor of Medicine, University of Minnesota Medical School, Minneapolis, MN, USA.

Urinary tract infections (UTIs) are a frequent diagnosis in older adults, leading to substantial antimicrobial use. Increased antimicrobial use is associated with higher rates of resistance, making future infections more difficult to treat. Unfortunately, many UTIs actually represent asymptomatic bacteriuria, which should not be treated in most cases. Adhering to clinical guidelines (based on high-quality evidence from randomized trials) would likely result in fewer UTI diagnoses, less antimicrobial use, and decreased antimicrobial resistance. Knowing when treatment for asymptomatic bacteriuria is recommended, and limiting therapy to these well defined circumstances is vital to appropriately managing a patient with a positive urine culture.
Key words: urinary tract infection, asymptomatic bacteriuria, catheter-associated bacteriuria, antimicrobial management.

Sophie Robichaud, MD, FRCP(C), Medical Microbiology and Pediatric Infectious Diseases, Royal University Hospital and Saskatoon Health Region, and Departments of Microbiology and Immunology and Pathology, University of Saskatchewan, Saskatoon, SK.
Joseph M. Blondeau, MSc, PhD, RSM(CCM), SM(AAM), SM(ASCP), FCCP, Head of Clinical Microbiology, Royal University Hospital and Saskatoon Health Region, and Adjunct Professor of Microbiology and Immunology, Clinical Assistant Professor of Pathology, Departments of Microbiology and Immunology and Pathology, University of Saskatchewan, Saskatoon, SK.

Urinary tract infections (UTIs) are the most common infectious problem among older adults both in the community and institutional settings. With the expected increase in this population, UTI-related costs--both human and financial--will rise in a parallel fashion. The diagnosis of symptomatic UTI among older adults is complicated by the high prevalence of asymptomatic bacteriuria, which does not require any treatment, and the difficulty in interpreting the signs and symptoms of UTI in a population in which significant comorbidities can undermine the communication between the patient and the medical team. Another important issue is the constant increase in antimicrobial resistance, especially in long-term care facilities, where antimicrobial use is greater than in the community. Newer agents are now available for the treatment of UTI among older adults, targeting both the usual and the multiresistant uropathogens. Rational use of antimicrobials in the treatment of UTI in the older adult is important to both provide appropriate care and control the spread of resistant organisms in this population.
Key words: urinary tract infection, older adults, UTI management, antimicrobials.

Dr. Lindsay E. Nicolle, MD, FRCPC, Department of Internal Medicine and Medical Microbiology, University of Manitoba, Winnipeg, MB.

The prevalence of asymptomatic bacteriuria increases with advancing age in community populations, and approaches 50% in the functionally impaired, institutionalized elderly. Asymptomatic bacteriuria is usually associated with pyuria, but has not been shown to contribute to any short- or long-term negative clinical outcomes in the older population. Treatment of asymptomatic bacteriuria is not recommended. Clinical trials evaluating antimicrobial therapy have found no improved outcomes, and therapy is usually followed by recurrence of bacteriuria. Antimicrobial treatment also is associated with increasing antimicrobial resistance and adverse drug effects. Due to the high prevalence of positive urine cultures, bacteriuria is not a useful diagnostic test for symptomatic urinary tract infection. However, a negative urine culture may exclude the urinary tract as a potential source of infection.
Key words: urinary tract infection, bacteriuria, older adults, long-term care.