urinary tract infection
DESCRIPTION
UTITRANSCRIPT
urinary tract infection (UTI)
• DEFINITIONS: UTI is the microbial invasion ofany tissue of the urinary tract, extending fromthe urethral meatus to the renal cortex.
• Categories: upper tract infections ( pyelonephritis: fever, flank pain + dysuriaand frequency), lower tract infection ( cystitis: dysuria, frequent passage of smallvolumes of urine), acute urethral syndrome
• Asymptomatic bacteriuria is the colonization ofthe urinary tract in the absence of symptoms. Itis usually defined by the presence of greaterthan 105 colonies per ml of urine.
Diagnostic testing:
Urinanalysis of thecentrifugated urin sediment: upper limit: 5-10 WBC/ highpower field on microscopeevalutaion
The presence of WBC casts is indicative for uper tractinfection
Dipstick test for nitrit is highlyspecific for infection
Urin culture: sign. bacteriuriadefined as more than 105/ml ofa single organism in culture ofa clean-catch midstream urinespecimen
Other forms of UTI
• Chronic pyelonephritis: chronic interstitial nephritis resultedfrom chronic ascending bacterial infection
• Papillary necrosis: infection of the renal pyramids seenmostly in diabetic patients. Symptomes:haematuria, flank pain, chills,fever, acute renal failure. X-ray finding: ring shadow on ivpyelography. Nephrectomy might be life saving
• Perinephric and renal abscesses: a complication ofbacterial pyelonephritis. Predisposing conditions: diabetes, nephroliths causing local obstruction of urinary flow, immunodeficiency. Suspition for this complication should arise whenpatient cured for acute pyelonephritis remain febrile after 5 days. Urine culture yields a polymicrobial flora. US or CT useful in thediagnosis. Treatment: drainage of pus, antibiotic diretcted at theorganisms recovered