Microbial invasion of any part of urinary tract — most commonly E. coli; uncomplicated cystitis to pyelonephritis.
History taking
- • Dysuria, frequency, urgency, suprapubic pain, haematuria
- • Fever, flank pain, vomiting (upper tract)
- • Recurrence, sexual activity, catheterisation, pregnancy, diabetes
Examination
- • Suprapubic tenderness, costovertebral angle tenderness
- • Vitals — exclude sepsis
Red flags
- • Fever, vomiting, sepsis signs → pyelonephritis
- • Pregnancy, immunocompromised, obstructive uropathy
- • Catheter-associated UTI with sepsis
Differential diagnosis
- • Vaginitis, urethritis (STI), interstitial cystitis
- • Pelvic inflammatory disease, prostatitis
Recommended investigations
- • Urine dipstick (nitrites, leucocyte esterase) — sufficient in uncomplicated
- • Urine routine & culture in complicated, pregnant, recurrent
- • CBC, RFT, blood culture, USG KUB if pyelonephritis
Diagnosis
- • Symptoms + positive dipstick or culture (≥10⁵ CFU/mL)
Initial treatment / management
- • Hydration; empirical antibiotic by local resistance
- • Uncomplicated cystitis: Nitrofurantoin 5 d OR Fosfomycin 3 g single dose
- • Pyelonephritis: Ceftriaxone IV, then oral per culture x 10–14 d
Prescription examples
- • Tab Nitrofurantoin 100 mg PO BD x 5 d
- • Tab Fosfomycin 3 g PO single dose
- • Tab Cefixime 200 mg PO BD x 7 d (alternative)
- • Inj Ceftriaxone 1–2 g IV OD (pyelonephritis)
Follow-up advice
- • Most resolve in 48–72 h; return if not improving
- • Test of cure in pregnancy
Patient counselling
- • Adequate fluids, perineal hygiene, post-coital voiding
- • Cranberry products: limited evidence
- • Recurrence: consider prophylaxis or post-coital antibiotic
Referral criteria
- • Recurrent UTI in male (any), urological evaluation
- • Pyelonephritis with sepsis, obstruction (USG hydronephrosis)
- • Pregnancy with UTI for obstetric review
Clinical pearls
- • Asymptomatic bacteriuria treated only in pregnancy & before urological surgery
- • Avoid nitrofurantoin if CrCl <30 or pyelonephritis (no tissue levels)
References
- • IDSA Guidelines on Uncomplicated UTI 2010
- • EAU Guidelines on Urological Infections 2024
Educational outpatient guide — verify against local guidelines before clinical use.
