Download Understanding Asymptomatic Bacteriuria

5/21/2012
Understanding
Asymptomatic
Bacteriuria
Serena Von Ruden, PharmD, RN, BSN
PGY1 Pharmacy Practice Resident
St. Joseph Medical Center
Tacoma, Washington
Learning Objectives
 Differentiate asymptomatic bacteriuria (ASB)
from a urinary tract infection
 List patient populations with higher
prevalence of ASB
 Describe when bacteriuria should be treated
 Discuss the potential hazards of
overtreatment
Asymptomatic Bacteriuria (ASB)1
 Bacterial growth ≥ 105 CFU/mL
 Non-contaminated urine sample
 No signs or symptoms of UTI
 May include pyuria
 For women, same organism in ≥ 2
consecutive specimens
1.
Nicolle LE, et al. Clin Infect Dis. 2005;40:643-654.
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Who has ASB?2
 Urinary catheters
 Impairment in bladder emptying
 Cerebrovascular disease
 Alzheimer’s or Parkinson’s disease
 Diabetes mellitus
 Institutionalized patients without urinary
catheters3


25-50% women
15-40% men
2. Beveridge LA, et al. Clin Interv Aging. 2011;6:173-180.
3. Nicolle L. Infect Dis Clin N Am. 1997;11:647-662.
Who should be treated?1,4
 Patients with symptoms
 Urgency, hesitancy, frequency, dysuria, fever
 Pregnant women
 Should be screened at 12-16 weeks
 Invasive urologic procedures
 Unclear evidence
 critically ill
 neutropenic
 renal transplants
 joint replacement surgery
1. Nicolle LE, et al. Clin Infect Dis. 2005;40:643-654.
4. Lin K, Fajardo K. Ann Intern Med. 2008;149:W 20-W24.
What about patients unable to
verbalize symptoms?
 Difficult to assess
 Non-specific presentation with confusion or
fever
 In febrile institutionalized patients, bacteriuria
has low PPV 8-11% for UTI5,6
5. Orr P, et al. Am J Med. 1996;100:71-77.
6. Warren J, et al. J Infect Dis. 1987;155:1151-1158.
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Hazards of Overtreatment
 Side effects
 Clostridium difficile infection7
 Colonization with drug-resistant organisms
 Undue costs
 Inappropriate treatment rates
 between 17-26%8,9
 up to 52% with urinary catheters10
7. Stevens V, et al. Clin Infect Dis. 2011;53:42-48.
8. Hecker MT, et al. Arch Intern Med. 2003;163:972-978.
9. Gandhi T, et al. Infect Control Hosp Epidemiol. 2009;30:193-195.
10. Dalen DM, et al. Can J Infect Dis Med Microbiol. 2005;16:166-170.
Should patients with indwelling
catheters be screened?11
 No
 Biofilm usually causes universal bacteriuria
by 4th day2
 In symptomatic patients with catheter ≥ 2
weeks


Discontinue catheter
Obtain midstream specimen or specimen from
new catheter
2. Beveridge LA, et al. Clin Interv Aging. 2011;6:173-180.
11. Hooton TM, et al. Clin Infect Dis. 2010;50:625-663.
Summary
 Do not routinely screen UA or culture
 Order UA or culture only for symptoms or
high clinical index of suspicion for infection
 Treat symptomatic UAs only when bacteria
and significant pyuria present
 Remove current catheter before sampling for
symptomatic patients with chronic
catheterization
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References
1. Nicolle LE, et al. Infectious Diseases Society of America guidelines for the diagnosis and
treatment of asymptomatic bacteriuria in adults. Clin Infect Dis. 2005;40:643-654.
2. Beveridge LA, et al. Optimal management of urinary tract infections in older people. Clin Interv
Aging. 2011;6:173-180.
3. Nicolle L. Asymptomatic bacteriuria in the elderly. Infect Dis Clin N Am. 1997;11:647-662.
4. Lin K, Fajardo K. Screening for asymptomatic bacteriuria in adults: evidence for the U.S.
Preventive Services Task Force reaffirmation recommendation statement. Ann Intern Med.
2008;149:W20-W24.
5. Orr P, et al. Febrile urinary tract infection in the institutionalized elderly. Am J Med.
1996;100:71-77.
6. Warren J, et al. Fever, bacteremia, and death as complications of bacteriuria in women with
long-term urethral catheters. J Infect Dis. 1987;155:1151-1158.
7. Stevens V, et al. Cumulative antibiotic exposures over time and the risk of Clostridium difficile
infection. Clin Infect Dis. 2011;53:42-48.
8. Hecker MT, et al. Unnecessary use of antimicrobials in hospitalized patients: current patterns
of misuse with an emphasis on the antianaerobic spectrum of activity. Arch Intern Med.
2003;163:972-978.
9. Gandhi T, et al. Importance of urinary tract infection to antibiotic use among hospitalized
patients. Infect Control Hosp Epidemiol. 2009;30:193-195.
10. Dalen DM, Zvonar RK, Jessamine PG. An evaluation of the management of asymptomatic
catheter-associated bacteriuria and candiduria at The Ottawa Hospital. Can J Infect Dis Med
Microbiol. 2005;16:166-170.
11. Hooton TM, et al. Diagnosis, prevention, and treatment of catheter-associated urinary tract
infection in adults: 2009 international clinical practice guidelines from the Infectious Diseases
Society of America. Clin Infect Dis. 2010;50:625-663.
12. Meyrier A. Urine sampling and culture in the diagnosis of urinary tract infection in adults. In:
UpToDate, Basow, DS (Ed), UpToDate, Waltham, MA, 2012.
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