Urinary tract infection (lower) in adults


  • Incidence: 3500.00 cases per 100,000 person-years
  • Peak incidence: 70+ years
  • Sex ratio: more common in females 20:1
Condition Relative
Urinary tract infection (lower) in adults1
Acute pyelonephritis0.03
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Clinical features


In elderly patients, acute confusion is a common feature.


Non-pregnant women
  • local antibiotic guidelines should be followed if available
  • CKS/2012 SIGN guidelines recommend trimethoprim or nitrofurantoin for 3 days
  • send a urine culture if:

Pregnant women
  • if the pregnant woman is symptomatic:
    • a urine culture should be sent in all cases
    • should be treated with an antibiotic for
    • first-line: nitrofurantoin (should be avoided near term)
    • second-line: amoxicillin or cefalexin
    • trimethoprim is teratogenic in the first trimester and should be avoided during pregnancy
  • asymptomatic bacteriuria in pregnant women:
    • a urine culture should be performed routinely at the first antenatal visit
    • Clinical Knowledge Summaries recommend an immediate antibiotic prescription of either nitrofurantoin (should be avoided near term), amoxicillin or cefalexin. This should be a 7-day course
    • the rationale of treating asymptomatic bacteriuria is the significant risk of progression to acute pyelonephritis
    • a further urine culture should be sent following completion of treatment as a test of cure

  • an immediate antibiotic prescription should be offered for 7 days
  • as with non-pregnant women, trimethoprim or nitrofurantoin should be offered first-line unless prostatitis is suspected
  • NICE Clinical Knowledge Summaries state: 'Referral to urology is not routinely required for men who have had one uncomplicated lower urinary tract infection (UTI).'

Catherised patients
  • do not treat asymptomatic bacteria in catheterised patients
  • if the patient is symptomatic they should be treated with an antibiotic
    • a 7-day, rather than a 3-day course should be given