Urinary Tract Tex1

Urinary Tract Tex1 - patients with asymptomatic bacteriuria...

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Urinary Tract Text 3. Diagnosis Laboratory diagnosis of UTI is made problematic by the fact that it is difficult to obtain a truly sterile urine specimen from voided urine: contamination by meatal organisms is frequent. If a urine sample is left at room temperature for hours, these organisms may grow to high numbers. Thus, for patients with asymptomatic bacteriuria (no symptoms), a high threshold is required to document true bacteriuria (vs contamination), i.e. 10 5 bacteria per ml. By contrast, in patients with typical symptoms, a much lower threshold is accepted, i.e. 10 2 bacteria per ml. Most patients with true bacteriuria have pus cells in the urine (pyuria), at least 10 5 per high-power field under the microscope or a positive leukocyte esterase dipstick test. Pyuria is a fairly sensitive indicator for true bacteriuria but it is not very specific as a guide to treatment because many
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Unformatted text preview: patients with asymptomatic bacteriuria (of whom only selected subgroups should be treated) have pyuria as do some patients with noninfectious inflammatory conditions (e.g. allergic interstitial nephritis). 4. Treatment The most common causes of UTI are E. coli (85%), Staphylococcus saprophyticus (5-10%), and other enteric gram-negatives (5-10%). These organisms are nearly always susceptible to quinolones. Nowadays, about 20-30% are resistant to TMP-SMX. For reasons not entirely clear, quinolones and trimethoprim-sulfamethoxazole (TMP-SMX) are more effective than beta-lactams for UTI even if the organisms are susceptible to the beta-lactams. For cystitis, a superficial infection, 3 days of treatment usually suffices. For uncomplicated pyelonephritis (no obstruction or other anatomic problem), 2 weeks suffices....
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This note was uploaded on 03/02/2012 for the course BSC BSC1086 taught by Professor Joystewart during the Fall '10 term at Broward College.

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