II. Epidemiology: Incidence: Asymptomatic Bacteriuria

  1. Children: 1-2% in girls (<1% in boys)
  2. Healthy women
    1. Sexually active women: 5%
    2. Pregnancy: 2-10%
    3. Postmenopausal women 50-70 years old: 2 to 8%
    4. Older women in community: Up to 20%
  3. Men over age 75 years old in community: 15%
  4. Long-term care residents: Up to 40-50%
    1. Diabetes Mellitus: 11 to 16% in women (1 to 11% in men)
  5. Spinal cord injury (e.g. Paraplegia)
    1. Intermittent catheterization: 23 to 69%
    2. Sphincterotomy and Condom catheter: 57%
  6. Renal Transplant
    1. Post-transplant <1 month: 24%
    2. Post-transplant 1 month to 1 year: 10 to 17%
    3. Post-transplant >1 year: 2 to 9%
  7. Indwelling Urinary Catheter
    1. Short-term catheter (<1 month): Increases 3-5% each day the catheter is present
    2. Long-term catheter: 100%
  8. References
    1. Nicolle (2019) Clin Infect Dis 68(10): e83-110 +PMID: 30895288 [PubMed]

III. Diagnosis

  1. Asymptomatic patient AND
  2. Urine Culture with >100,000 colony forming units/ml of a single Bacteria

IV. Precautions

  1. Most Asymptomatic Bacteriuria resolves without treatment (including catheterized patients)
  2. Avoid prophylactic antibiotics (ineffective and risk of Antibiotic Resistance)
  3. Infectious Disease Society of America (IDSA) does not recommend routine UA/UC in asymptomatic patients
    1. Unlikely to offer benefit (poor Specificity for UTI in the absence of urinary tract symptoms)
    2. Risk of Antibiotic Resistance and adverse effects (e.g. Clostridium difficile)

V. Labs

  1. Indications for Urinalysis and Urine Culture
    1. Screening for Asymptomatic Bacteriuria in Pregnancy
    2. Screening prior to invasive urologic procedures
      1. Includes transurethral surgery, ureteroscopy, lithotripsy, percutaneous nephrolithotomy
      2. No treatment needed in procedures that do not disrupt mucosa (e.g. diagnostic cystoscopy)
    3. Symptoms suggestive of Urinary Tract Infection (e.g. Dysuria, urgency, frequency)
    4. Cloudy, malodorous or other urine abnormality (however, may also be due to Dehydration)
    5. Spinal cord injury with systemic symptoms
      1. Fever, malaise, lethargy, spasticity or Autonomic Dysreflexia
      2. New or worsening Urinary Incontinence or leakage around catheter
      3. Cloudy or malodorous urine, back or Flank Pain, Suprapubic Pain or Dysuria
  2. Cases in which screening is not recommended
    1. Asymptomatic non-pregnanct patients (including catheterized patients)
    2. Non-specific symptoms (e.g. weakness, malaise) EXCEPT catheterized or spinal cord injury patients
      1. See Urinary Catheter associated UTI
      2. Consider other causes of confusion or falls in the elderly first (e.g. Anticholinergic Medications)
        1. However in those with Sepsis, and other sources not identified, treat as symptomatic UTI
      3. Treatment of abnormal urine and nonspecific symptoms does not reduce Fall Risk
        1. Rowe (2013) J Am Geriatr Soc 61(4):653-4 +PMID:23581923 [PubMed]
  3. Interpretations
    1. Even pyuria and urine nitrates are non-specific and may not warrant antibiotics

VI. Management

  1. Indications for treatment of Asymptomatic Bacteriuria
    1. Asymptomatic Bacteriuria in Pregnancy
    2. Urologic procedures that may result in bleeding
  2. Cases in which screening and antibiotics are not indicated
    1. Asymptomatic Bacteriuria in infants and children
    2. Asymptomatic Bacteriuria in non-pregnant women
    3. Urinary Catheter Associated Asymptomatic Bacteriuria (differentiate from CAUTI)
    4. Asymptomatic Bacteriuria in Diabetes Mellitus
    5. Asymptomatic Bacteriuria in Spinal Cord Injuries (no systemic symptoms - see above)
    6. Asymptomatic Bacteriuria in Older patients

VII. Prognosis

  1. Spontaneous resolution
    1. Simple cystitis (typical cystitis, positive UA) without antibiotics resolves in 25-50% within 1 week
  2. Progression cystitis to pylenophritis
    1. Progression to Pyelonephritis occurs in 1 in 38 cases (2.6%)

VIII. References

  1. (2019) Presc Lett 26(6)
  2. (2015) Presc Lett 22(4)
  3. Orman and Glaser in Herbert (2016) EM:Rap 16(1): 8-9
  4. Colgan (2020) Am Fam Physician 102(1):99-104 [PubMed]
  5. Colgan (2006) Am Fam Physician 74(6):985-90 [PubMed]
  6. Nicolle (2005) Clin Infect Dis 40:643-54 [PubMed]

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Related Studies

Ontology: Asymptomatic bacteriuria (C0262380)

Concepts Disease or Syndrome (T047)
SnomedCT 197925009, 236704009
Italian Batteriuria asintomatica
Japanese 無症候性細菌尿, ムショウコウセイサイキンニョウ
English asymptomatic bacteruria (diagnosis), asymptomatic bacteruria, asymptomatic bacteriuria, bacteriuria asymptomatic, Bacteriuria, site not specified, Bacteriuria: [site not specified] or [asymptomatic], Bacteriuria: [site not specified] or [asymptomatic] (disorder), Asymptomatic bacteriuria, ASB - Asymptomatic bacteriuria, Asymptomatic bacteriuria (disorder), asymptomatic; bacteriuria, bacteriuria; asymptomatic
Czech Asymptomatická bakteriurie
Hungarian Panaszmentes bacteriuria
Dutch asymptomatisch; bacteriurie, bacteriurie; asymptomatisch, asymptomatische bacteriurie
Spanish bacteriuria asintomática (trastorno), bacteriuria asintomática, Bacteriuria asintomática
Portuguese Bacteriúria assintomática
French Bactériurie asymptomatique
German asymptomatische Bakteriurie