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Urinary tract infections (UTIs) are among the most common bacterial infections encountered in medicine. Accurately estimating incidence is difficult because UTIs are not reportable, but they are estimated to result in 10.5 million office visits and 2–3 million emergency department visits per year in the United States.

A UTI is defined by urologists as any infection involving the urothelium, which includes urethral, bladder, prostate, and kidney infections. Some of these are diseases that have been clearly characterized (eg, cystitis and pyelonephritis), whereas others (eg, urethral and prostate infections) are not as well understood or described.

The terms simple UTI and uncomplicated UTI are often used to refer to cystitis. In this chapter, UTI is used to refer to any infection of the urinary tract, and cystitis is used to specify a bladder infection. The generic term complicated UTI is often used to refer to cystitis occurring in a person with preexisting metabolic, immunologic, or urologic abnormalities, including kidney stones, diabetes, and acquired immunodeficiency syndrome (AIDS), or caused by multidrug-resistant organisms.

Asymptomatic bacteriuria, uncomplicated cystitis, complicated cystitis, two urethral syndromes, four prostatitis syndromes, and pyelonephritis are discussed in this chapter. Although separated into different diagnoses, differentiating among syndromes and deciding treatment is left to the clinician’s discretion.

Antibiotic resistance is a topic that has been left mostly to the reader. General recommendations about specific antibiotics are inappropriate, given that antibiotic resistance differs from location to location. It is the responsibility of individual physicians to be familiar with local antibiotic resistances and to determine the best first-line therapies for their practice. Always keep in mind that antibiotic use breeds resistance, and try to keep first-line drugs as simple and narrow spectrum as possible.

Drekonja  DM, Johnson  JR. Urinary tract infections. Prim Care. 2008:35:345–367; vii.
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Flores-Mireles  AL, Walker  JN, Caparon  M, Hultgren  SJ. Urinary tract infections: epidemiology, mechanisms of infection and treatment options. Nat Rev Microbiol. 2015;13(5):269–284.
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  • Asymptomatic patient.

  • Urine culture with more than 105 colony-forming units (CFUs); bacteria in spun urine; or urine dipstick analysis positive for leukocytes, nitrites, or both.

General Considerations

Asymptomatic bacteriuria is defined separately for men, women, and the type of specimen. For women, clean-catch voided specimens on two separate occasions must contain >105 CFU/mL of the same bacterial strain, or one catheterized specimen must contain >102 CFU/mL of bacteria. For men, a single clean-catch specimen with >105 CFU/mL of bacteria or one catheterized specimen with >102 CFU/mL of bacteria suffices for the diagnosis. By definition, the patient must be asymptomatic, that is, should not be experiencing dysuria, suprapubic pain, fever, urgency, frequency, or incontinence. Screening for bacteriuria does not need to be done in young, ...

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