Upon completion of the chapter, the reader will be able to:
Determine the diagnostic criteria for significant bacteruria, urinary tract infections (UTIs), and catheter-associated UTIs.
Recognize the signs and symptoms of urinary tract infections (UTIs), and differentiate asympotomatic bacteriuria from acute cystitis and pyelonephritis, and acute prostatitis from chronic prostatitis.
Identify the pathogenic organisms most commonly implicated in different UTIs.
Assess the laboratory tests used in the diagnosis of UTIs.
Based on clinical signs, symptoms, and laboratory parameters, recommend appropriate empiric and targeted pharmacotherapy for the treatment of acute cystitis, pyelonephritis, and prostatitis, including drug, dose, and duration of therapy.
Formulate appropriate monitoring and education information for patients with UTIs.
A urinary tract infection (UTI) is defined as the presence of pathogenic microorganisms in the genitourinary tract with associated signs and symptoms of infection. UTIs represent a diverse array of syndromes based on location within the urinary tract, including acute cystitis, pyelonephtritis, and prostatitis.1–3 UTIs are one of the most common reasons for the prescribing of antimicrobial therapy.4
EPIDEMIOLOGY AND ETIOLOGY
The prevalence and type of UTIs generally vary according to age and gender.5,6 In adults, bacteriuria is more common in young, nonpregnant women (range, 1%–3%), but uncommon in men (up to 0.1%).7 Symptomatic UTIs occur most frequently in women of childbearing age. It is estimated that the lifetime risk of UTIs in women is as high as 60%, with 25% of those patients experiencing a recurrence within 1 year.8 UTIs are much more common in women and men due to their inherently shorter urethra and location in the perineal area. However, older men may experience UTIs due to immunoscenesence and concomitant disease states, such as benign prostatic hypertrophy (BPH).
UTIs can be classified as either uncomplicated or complicated. Uncomplicated infections usually occur in women of childbearing age. Complicated UTIs usually occur in patients who have structural or functional abnormalities of the genitourinary tract, and may involve the bladder or the kidneys.2 Male patients with UTIs are considered complicated, and most older adults will also meet this criterion. Although complicated infections are usually treated similar to uncomplicated infections, a longer treatment duration is typically warranted in complicated infections. UTIs can also be classified as upper and lower depending on their anatomical location. Lower UTIs usually refer to acute cystitis, whereas upper UTIs refer to pyelonephritis. It is important to note that an upper UTI does not necessarily imply complicated UTI, nor does a lower UTI imply uncomplicated UTI.
The etiologic pathogens of most UTIs originate from the perirectal area. Escherichia coli is implicated in more than 80% of uncomplicated infections, with Klebsiella pneumoniae and Proteus species being less common.9 Gram-positive organsisms, such as Staphylococcus saprophyticus and Enterococcus species, are uncommon but potential causes.10,11 Although E. coli...