UTIs

Higher prevalence in female due to:

• Brevity of the female urethra,
• proximity of the urethra from the rectum and vagina, and decreased urethral resistance during pregnancy and after menopause

Sexual intercourse and hypoestrogenism are important risk factors for the development of UTIs

In elderly, estrogen deficiency -> mucosal dryness -> lack of protective bacterial flora -> increased risk of UTI

Tx -  vaginal estrogen creams

Men with UTIs have anatomic abnormalities much more often than women

Most commonly involved bugs

E. coli (80%)

Staph. saprophyticus

Klebsiella pneumoniae

Proteus mirabilis and P. vulgarus --> urease splits urea into NH3 and CO2 --> ammonium-magnesium-phosphate stones

Pseudomonas aeruginosa (nosocomial, catheter associated)

Dx

Best initial test:  urinalysis with >10 WBCs

Most accurate test: urine culture

(skip to treatment if clear symptoms of cystitis and WBCs in urine)

Differentiating a relapse from a recurrent UTI may be difficult. In general, if the infecting organism is different from that of the original infection, it is called a recurrence.

If the infecting organism is the same original infecting organism within 2 weeks of completion of treatment, it is called a relapse.