II. Epidemiology: Incidence: Asymptomatic Bacteriuria
- Children: 1-2% in girls (<1% in boys)
- Healthy women
- Sexually active women: 5%
- Pregnancy: 2-10%
- Postmenopausal women 50-70 years old: 2 to 8%
- Older women in community: Up to 20%
- Men over age 75 years old in community: 15%
- Long-term care residents: Up to 40-50%
- Diabetes Mellitus: 11 to 16% in women (1 to 11% in men)
-
Spinal Cord Injury (e.g. Paraplegia)
- Intermittent catheterization: 23 to 69%
- Sphincterotomy and Condom catheter: 57%
-
Renal Transplant
- Post-transplant <1 month: 24%
- Post-transplant 1 month to 1 year: 10 to 17%
- Post-transplant >1 year: 2 to 9%
- Indwelling Urinary Catheter
- Short-term catheter (<1 month): Increases 3-5% each day the catheter is present
- Long-term catheter: 100%
- References
III. Diagnosis
- Asymptomatic patient AND
- Urine Culture with >100,000 colony forming units/ml of a single Bacteria
IV. Precautions
- Most Asymptomatic Bacteriuria resolves without treatment (including catheterized patients)
- Avoid prophylactic antibiotics (ineffective and risk of Antibiotic Resistance)
- Infectious Disease Society of America (IDSA) does not recommend routine UA/UC in asymptomatic patients
- Unlikely to offer benefit (poor Specificity for UTI in the absence of urinary tract symptoms)
- Risk of Antibiotic Resistance and adverse effects (e.g. Clostridium difficile)
V. Labs
- Indications for Urinalysis and Urine Culture
- Screening for Asymptomatic Bacteriuria in Pregnancy
- Screening prior to invasive urologic procedures
- Includes transurethral surgery, ureteroscopy, lithotripsy, percutaneous nephrolithotomy
- No treatment needed in procedures that do not disrupt mucosa (e.g. diagnostic cystoscopy)
- Symptoms suggestive of Urinary Tract Infection (e.g. Dysuria, urgency, frequency)
- Cloudy, malodorous or other urine abnormality (however, may also be due to Dehydration)
- Spinal Cord Injury with systemic symptoms
- Fever, malaise, lethargy, spasticity or Autonomic Dysreflexia
- New or worsening Urinary Incontinence or leakage around catheter
- Cloudy or malodorous urine, back or Flank Pain, Suprapubic Pain or Dysuria
- Cases in which screening is not recommended
- Asymptomatic non-pregnanct patients (including catheterized patients)
- Non-specific symptoms (e.g. weakness, malaise) EXCEPT catheterized or Spinal Cord Injury patients
- See Urinary Catheter associated UTI
- Consider other causes of confusion or falls in the elderly first (e.g. Anticholinergic Medications)
- However in those with Sepsis, and other sources not identified, treat as symptomatic UTI
- Treatment of abnormal urine and nonspecific symptoms does not reduce Fall Risk
- Interpretations
- Even pyuria and urine nitrates are non-specific and may not warrant antibiotics
VI. Management
- Indications for treatment of Asymptomatic Bacteriuria
- Asymptomatic Bacteriuria in Pregnancy
- Urologic procedures that may result in bleeding
- Cases in which screening and antibiotics are not indicated
- Asymptomatic Bacteriuria in infants and children
- Asymptomatic Bacteriuria in non-pregnant women
- Urinary Catheter Associated Asymptomatic Bacteriuria (differentiate from CAUTI)
- Asymptomatic Bacteriuria in Diabetes Mellitus
- Asymptomatic Bacteriuria in Spinal Cord Injuries (no systemic symptoms - see above)
- Asymptomatic Bacteriuria in Older patients
VII. Prognosis
- Spontaneous resolution
- Simple cystitis (typical cystitis, positive UA) without antibiotics resolves in 25-50% within 1 week
- Progression cystitis to pylenophritis
- Progression to Pyelonephritis occurs in 1 in 38 cases (2.6%)
VIII. References
- (2019) Presc Lett 26(6)
- (2015) Presc Lett 22(4)
- Orman and Glaser in Herbert (2016) EM:Rap 16(1): 8-9
- Colgan (2020) Am Fam Physician 102(1):99-104 [PubMed]
- Colgan (2006) Am Fam Physician 74(6):985-90 [PubMed]
- Nicolle (2005) Clin Infect Dis 40:643-54 [PubMed]