Urinary Tract Infection (UTI)

Last updated 30/06/14

Definition

• Growth of >10(5) organisms/ml in a clean catch urinalysis
• UTI in Pregnancy
• Paediatric UTI
• Cystitis = UTI effecting the bladder

Features

• Lower tract infections: urethritis, cystitis
• Upper tract infection: pyelonephritis, prostatitis, perinephric/intrarenal abscess
• Symptomatic vs asymptomatic
• Asymptomatic bacteruria 40-50% of adults >50yrs old
• Asymptomatic bacteruria still treated in pregnancy
• Increased incidence with sexual activity (especially women)
• Closer proximity of urethra to anus & shorter urethra
• Majority of acute symptomatic UTIs (Cystitis) are in young women
• Unusual in men <50yrs old

Cause

• Gram negative bacilli
• E. Coli
• 80% of acute UTIs wihout complication
• Proteus, Klebsiella: propensity for stone formation
• Proteus, Klebsiella, Pseudomonas, Serratia
• Found in urological pathology or from catheter (IDC, SPC)
• Gram positive cocci
• Staph saprophyticus: 10-15% of acute UTIs in young women
• Enterococcus, Staph aureus: assocaited with urolithiasis or urological surgery
• Associated with STIs: Chlamydia, Gonorrhoea, HSV

Risk Factors

• Young Women
• Antibiotics
• Contraception: especially spermaticides
• Sexually transmitted infections: Chlamydia, Gonorrhoea...
• Pregnancy
• All women screened in first trimester
• Common post partum infection
• Men <50yrs old
• Rectal intercourse
• Catheter (IDC, SPC)
• 3-5% risk per day
• Urinary obstruction
• Neurogenic bladder: DM, MS, Spinal Cord Injury (SCI)
• Vesicoureteric reflux (VUR): children

Associated S/S

• Urethritis
• 30% women with acute dysuria, frequency, pyuria without significant bacteruria
• Cystitis
• Dysuria, frequency, urgency
• Suprapubic pain
• Cloudy malodourous urine
• Haematuria 30%
• Acute Pyelonephritis
• Fever >38.3
• Nausea, vomiting
• Costovertebral tenderness (Knocking pain)
• Diarrhoea
• Tachycardia, hypotension, sepsis

Complications

• Pyelonephritis
• Urosepsis

Investigations

• Dipstick
• Leukocyte esterase
• Nitrites
• Urinalysis
• Dx: growth >10(5) organisms/mil ina clean catch
• Some UTIs lack significant bacteruria, if symptomatic aspiration or catheter sample
• >10(2) to 10(4)/ml = infection
• Microscopy: gram stain, pyuria
• CT-KUB indicated if
• Relapsing UTIs in women
• History of recurrent childhood infections
• Urolithiasis
• Painless haematuria

Management

• As per complications
• Urinary obstruction
• Urolithiasis
• Symptomatic Mx
• Ural: helps with dysuria
• Antibiotics
• Acute Cystitis
• Wait for sensitivities or empiracal treatment if significantly symptomatic
• Trimethoprim 300mg PO Daily for 3-5/7 or 200mg BD for 5/7
• OR Ciprofloxacin
• OR Norfloxacin
• OR Nitrofuranitoin 50-100mg PO QID for 5/7
• Urological pathology or catheter (IDC, SPC)
• Mild S/S
• Ciprofloxacin
• Chase sensitivities
• Severe S/S
• Admit
• IV Imipenem
• OR Ceftriaxone
• Await sensitivities
• Prevention
• Voiding post coitus for women

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References


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