A Panel of International Experts was convened by the Infectious Diseases Society of America (IDSA) in collaboration with the European Society for Microbiology and Infectious Diseases (ESCMID) to update the 1999 Uncomplicated Urinary Tract Infection Guidelines by the IDSA. Co-sponsoring organizations include the American Congress of Obstetricians and Gynecologists, American Urological Association, Association of Medical Microbiology and Infectious Diseases-Canada, and the Society for Academic Emergency Medicine. The focus of this work is treatment of women with acute uncomplicated cystitis and pyelonephritis, diagnoses limited in these guidelines to premenopausal, non-pregnant women with no known urological abnormalities or co-morbidities. The issues of in vitro resistance prevalence and the ecological adverse effects of antimicrobial therapy (collateral damage) were considered as important factors in making optimal treatment choices and thus are reflected in the rankings of recommendations.

Asymptomatic bacteriuria (ASB) is a common finding in many populations, including healthy women and persons with underlying urologic abnormalities. The 2005 guideline from the Infectious Diseases Society of America recommended that ASB should be screened for and treated only in pregnant women or in an individual prior to undergoing invasive urologic procedures. Treatment was not recommended for healthy women; older women or men; or persons with diabetes, indwelling catheters, or spinal cord injury. The guideline did not address children and some adult populations, including patients with neutropenia, solid organ transplants, and nonurologic surgery. In the years since the publication of the guideline, further information relevant to ASB has become available. In addition, antimicrobial treatment of ASB has been recognized as an important contributor to inappropriate antimicrobial use, which promotes emergence of antimicrobial resistance. The current guideline updates the recommendations of the 2005 guideline, includes new recommendations for populations not previously addressed, and, where relevant, addresses the interpretation of nonlocalizing clinical symptoms in populations with a high prevalence of ASB.

Community-acquired urinary tract infections (UTIs) are among the most common bacterial infections in women. Therapy for these infections is usually begun before results of microbiological tests are known. Furthermore, in women with acute uncomplicated cystitis, empirical therapy without a pretherapy urine culture is often used. The rationale for this approach is based on the highly predictable spectrum of etiologic agents causing UTI and their antimicrobial resistance patterns. However, antimicrobial resistance among uropathogens causing community-acquired UTIs, both cystitis and pyelonephritis, is increasing. Most important has been the increasing resistance to trimethoprim-sulfamethoxazole (TMP-SMX), the current drug of choice for treatment of acute uncomplicated cystitis in women. What implications do these trends have for treatment of community-acquired UTIs? Preliminary data suggest that clinical cure rates may be lower among women with uncomplicated cystitis treated with TMP-SMX when the infecting pathogen is resistant to TMP-SMX. Women with pyelonephritis also have less bacterial eradication and lower clinical cure rates when treated with TMP-SMX for an infection that is resistant to the drug. Therefore, in the outpatient setting, identifying risk factors for TMP-SMX resistance and knowing the prevalence of TMP-SMX resistance in the local community are important steps in choosing an appropriate therapeutic agent. When choosing a treatment regimen, physicians should consider such factors as in vitro susceptibility, adverse effects, cost-effectiveness, and selection of resistant strains. Using a management strategy that takes these variables into account is essential for maintaining the safety and efficacy of treatment for acute UTI.

While the prevalence of resistance to trimethoprim-sulfamethoxazole, ampicillin, and cephalothin increased significantly among uropathogens causing acute cystitis, resistance to nitrofurantoin and ciprofloxacin remained infrequent. These in vitro susceptibility patterns should be considered along with other factors, such as efficacy, cost, and cost-effectiveness in selecting empirical therapy for acute uncomplicated cystitis in women.