Intended for healthcare professionals

Practice Rational Testing

Interpreting asymptomatic bacteriuria

BMJ 2011; 343 doi: (Published 04 August 2011) Cite this as: BMJ 2011;343:d4780

This article has a correction. Please see:

  1. Martin Cormican, professor of bacteriology1,
  2. Andrew W Murphy, professor of general practice2,
  3. Akke Vellinga, epidemiologist2
  1. 1Centre for Health from Environment, Ryan Institute, and Medical School, NUI Galway, Galway, Ireland
  2. 2Discipline of general Practice, Medical School, Clinical Science Institute, NUI Galway, Galway, Ireland
  1. Correspondence to: Professor M Cormican, Antimicrobial Resistance and Microbial Ecology Laboratory, Medical School, Clinical Science Institute, NUI Galway, Newcastle Road, Galway, Ireland martin.cormican{at}

Testing for and treating bacteriuria in children and non-pregnant adults without specific symptoms of urinary tract infection or sepsis is of uncertain benefit

Learning points

  • Asymptomatic bacteriuria refers to bacteria in the urine at levels often regarded as clinically significant ( >100 000 colony forming units per millilitre of urine) in patients with no symptoms suggestive of urinary tract infection. It becomes more common with age

  • Testing for and treating asymptomatic bacteriuria is of established value in pregnant women as it reduces the risk of pyelonephritis later in pregnancy by about 75%

  • Consider testing for bacteriuria in any patient with clinical features pointing to urinary tract infection (haematuria, dysuria, frequency, urge incontinence, or back pain) or to systemic sepsis without an apparent focus

  • If children, non-pregnant adults, or people with diabetes or indwelling urinary catheters lack specific symptoms of urinary tract infection or systemic infection, avoid testing them for and treating bacteriuria

  • Testing for bacteriuria in patients with stable stress incontinence is not appropriate as bacteriuria is not associated with stress incontinence in older people

  • If you feel obliged to try treating bacteriuria in a patient with non-specific or equivocal symptoms, urine culture can guide selection of the safest and most narrow spectrum agent possible; ensure careful assessment of clinical and microbiological response

Mrs A is a 74 year old woman who saw your locum two days ago with a two to three week history of feeling tired and vaguely unwell. She admitted to “leaking a bit of urine” whenever she coughs or lifts things, but has had this problem for two years. She has not had other urinary tract symptoms and has not had dysuria or frequency in recent years. She was prescribed an antibiotic two or three times in the past year by a doctor in another practice after positive laboratory …

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