Urinary tract infection (UTI) is a term that is applied to a variety of clinical conditions ranging from the asymptomatic presence of bacteria in the urine to severe infection of the kidney with resultant sepsis. UTI is one of the more common medical problems. It is estimated that 150 million patients are diagnosed with a UTI yearly, resulting in at least $6 billion in health care expenditures (Stamm and Norrby, 2001). UTIs are at times difficult to diagnose; some cases respond to a short course of a specific antibiotic, while others require a longer course of a broad-spectrum antibiotic. Accurate diagnosis and treatment of a UTI is essential to limit its associated morbidity and mortality and avoid prolonged or unnecessary use of antibiotics. Advances in our understanding of the pathogenesis of UTI, the development of new diagnostic tests, and the introduction of new antimicrobial agents have allowed physicians to appropriately tailor specific treatment for each patient.
The epidemiology of UTI grouped by age and sex is shown in Table 14–1. In newborns up to 1 year of age, bacteriuria is present in 2.7% of boys and 0.7% in girls (Wettergren et al, 1985). The incidence of UTI in uncircumcised males is higher than in circumcised males (1.12% compared with 0.11%) during the first 6 months of life (Wiswell and Roscelli, 1986). In children between 1 and 5 years of age, the incidence of bacteriuria in girls increases to 4.5%, while it decreases in boys to 0.5% (Randolph and Greenfield, 1964). Most UTIs in children younger than 5 years are associated with congenital abnormalities of the urinary tract, such as vesicoureteral reflux or obstruction. The incidence of bacteriuria remains relatively constant in children 6–15 years of age. However, the UTIs in these children are more likely to be associated with functional abnormalities of the urinary tract, such as dysfunctional voiding. During adolescence, the incidence of UTI significantly increases (to 20%) in young women, while remaining constant in young men (Sanford, 1975).
Table 14–1. Epidemiology of UTI by Age, Group, and Sex. |Favorite Table|Download (.pdf)
Table 14–1. Epidemiology of UTI by Age, Group, and Sex.
Foreskin, anatomic GU abnormalities
Anatomic GU abnormalities
Functional GU abnormalities
Sexual intercourse, diaphragm use
Surgery, prostate obstruction, catheterization
Incontinence, catheterization, prostate obstruction
Approximately 7 million cases of acute cystitis are diagnosed yearly in young women (Schappert, 1999); this likely is an underestimate of the true incidence of UTI because at least 50% of all UTIs do not come to medical attention. The major risk factors for women 16–35 years of age are related to sexual intercourse and diaphragm use. Later in life, ...