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GUIDING QUESTIONS
What are the virulence factors that allow bacteria to infect the urinary tract, and where do the bacteria come from?
What are the host factors that help to prevent infection of the urinary tract?
Which symptoms and signs help the clinician to differentiate upper tract (pyelonephritis) from lower tract disease (cystitis)?
How useful is the urinary sediment in diagnosing urinary tract infection?
When should a urine culture be ordered, and what represents a true positive culture? What does 105 CFU/mL mean?
How is prostatitis contracted, and which organisms are most likely to cause this infection?
How do the treatments of acute and chronic prostatitis differ?
How is urethritis differentiated from cystitis?
Does delay in treating urethritis lead to any serious complications in women?
What are the physical findings that accompany pelvic inflammatory disease (PID)?
Why should physicians have a low threshold for diagnosing and treating PID?
What are the most common causes of genital ulcers, and how can they be differentiated on clinical examination?
What are the three stages of syphilis, and how are they treated?
How do the VDRL (Venereal Disease Research Laboratory) and RPR (rapid plasma reagin) tests differ from the FTA-ABS (fluorescent treponemal antigen–antibody absorption) test, and how should these tests be utilized?
What is the leading cause of venereal warts, and what are the potential long-term consequences of having this infection?
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POTENTIAL SEVERITY
Often outpatient infections; however, the development of pyelonephritis or pelvic inflammatory disease can lead to sepsis and death. These infections need to be promptly treated.
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GENITOURINARY TRACT INFECTIONS: URINARY TRACT INFECTION
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Urinary tract infections (UTIs) are the most common infections seen in outpatient practice. Clinicians must understand the different types of UTIs and know how to diagnose and treat them.
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Any discussion of UTI must take into account bacterial virulence factors and host factors. The balance between the ability of a specific bacterium to invade the urinary tract and the ability of the host to fend off the pathogen determines whether the human host will develop a symptomatic UTI.
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Bacteria generally gain entry into the urinary system by ascending the urethra into the bladder and then, in some cases, ascending the ureters to the renal parenchyma. The organism that most commonly infects the urinary tract is Escherichia coli, and certain strains of E. coli are more likely to cause a UTI. These strains possess advantageous virulence characteristics, including increased ability to adhere to the epithelial cells of the urethra and increased resistance to serum cidal activity and hemolysin production. E. coli adhere by their fimbria or pili that are distinct protein hairlike structures on the bacterial surface. Pyelonephritis strains are the most adherent; cystitis strains tend to be intermediately adherent. Pathogenic strains that cause pyelonephritis are more likely to express ...