1 / 56

Asymptomatic Urinary Tract Infection

Asymptomatic Urinary Tract Infection. Edward L. Goodman, MD October 13, 2003. A Common Problem: Prevalence of AB in Ambulatory Persons. Young women: 1-2% Women >60 years: 6-10% Men >65 years: >5% Swedish city At 72 years, 6% men, 16% women VA outpatient men 65-74 years old: 9%

tommy
Download Presentation

Asymptomatic Urinary Tract Infection

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Asymptomatic Urinary Tract Infection Edward L. Goodman, MD October 13, 2003

  2. A Common Problem: Prevalence of AB in Ambulatory Persons • Young women: 1-2% • Women >60 years: 6-10% • Men >65 years: >5% • Swedish city • At 72 years, 6% men, 16% women • VA outpatient men • 65-74 years old: 9% • 75-84 years old: 15.3% Nicolle. Inf Dis Clin NA, 1997; 11: 647

  3. Elderly Institutionalized • Prevalence • Men: 15 – 35% • Women: 25 - 50% • Incidence Studies • NH with negative culture on admission • 11% men positive at one year • 23% women at one year • Another study: 10% acquire every 3 months Nicolle IDCNA 1997

  4. So, it’s common- big deal! • We’ve got The Sanford Guide • We can look it up conveniently • Who needs a lecture? • For those of us who can’t read the small print • We’ve got Epocrates • Current house staff were all born with a Palm Pilot™ clutched in their palm! • What’s the big deal – just treat it!

  5. BUT • All antibiotic use ultimately leads to microbial resistance • Resistance results in increased morbidity, mortality, and cost of healthcare; and • Appropriate antimicrobial stewardship should prevent or slow the emergence of resistance among organisms (Clin Inf Dis 1997; 25:584-99.) • Antibiotics are used as “drugs of fear” • (Kunin et al. Ann Int Med 1973;79:555)

  6. Antibiotic Misuse • Surveys reveal that: • 25 - 33% of hospitalized patients receive antibiotics (Arch Intern Med 1997;157:1689-1694) • 22 - 65% of antibiotic use in hospitalized patients is inappropriate (Infection Control 1985;6:226-230)

  7. Consequences of Misuse of Antibiotics • Contagious RESISTANCE • Nothing comparable for overuse of procedures, surgery, other drugs • Morbidity - drug toxicity • Mortality - MDR bacteria harder to treat • Cost

  8. Definitions: Asymptomatic Bacteriuria • “Gold standard” for bacteriuria = >=100,000 CFU/ml voided urine • Applied to Asymptomatic Bacteriuria • Almost always present in acute pyelonephritis • Kass, EH. Trans Assoc. Amer. Phys 69:56, 1956

  9. Definitions: Symptomatic Bacteriuria • Acute cystitis in women: >= 100 CFU/ml • 95% sensitivity; 85% specificity* • Acute pyelonephritis: > 100,000/ml** • (The standard 0.001 ml loop cannot detect <1000 organisms/ml) • *Stamm WE. NEJM 3229:1328, 1982 • **Kass 1956

  10. Infectious Disease Society Consensus Definition • Cystitis: >=10³ cfu/ml • Sensitivity 80%; Specificity 90% • Pyelonephritis: >=10,000 cfu/ml • Can be identified in routine micro labs using 0.001 ml loop • Rubin et al. Clinical Infectious Disease, 1992

  11. Symptoms • Acute: irritation, obstruction or inflammation – correlate with significant bacteriuria • Chronic: incontinence, hesitancy, hematuria – do not correlate with bacteriuria in elderly • In demented: non-specific symptoms such as altered mentation are fairly sensitive for systemic infection

  12. Colonization vs. Infection • Bacteriuria is almost always associated with a host response • Pyuria • Cytokinuria • HENCE, THE TERM COLONIZATION OF URINE IS OBSOLETE. It is infection, asymptomatic or symptomatic

  13. Why So Many Urine Cultures? • Annually 10,400 urine cultures are submitted to the PHD Microbiology Laboratory • Exceeded only by 14,000 blood cultures • At least one third from catheterized patients • Often cath specimens are mislabeled as voided • It is an effort to obtain a clean catch urine from a hospitalized patient • Catheter urine is so convenient to culture! • Nursing preferences play a major role

  14. HCW’s Attitudes and Perceptions • HCW interpret bacteriuria as symptomatic in presence of nonspecific symptoms • Urine cultures are thus ordered for nonspecific changes in patient’s status – part of the “panculture” mentality • Difficulty in eliciting information about symptoms in frail elderly

  15. Attitudes and Perceptions –2 • Physician’s uncertainty about significance and management of positive urine culture • Liability concerns • A positive culture left untreated looks “bad” in the chart • Walker et al. CMAJ 2000; 163 (3): 273

  16. Refrain: Prevalence of AB in Ambulatory Persons • Young women: 1-2% • Women >60 years: 6-10% • Men >65 years: >5% • Swedish city • At 72 years, 6% men, 16% women • VA outpatient men • 65-74 years old: 9% • 75-84 years old: 15.3% Nicolle, Inf Dis Clin NA, 1997

  17. Refrain II: Elderly Institutionalized • Prevalence • Men: 15 – 35% • Women: 25 - 50% • Incidence Studies • NH with negative culture on admission • 11% men positive at one year • 23% % women at one year • Another study: 10% acquire every 3 months Nicolle 1997

  18. Does Rx for AB Help? • All data is from elderly in long term care facilities • Early studies (Platt, NEJM 1982;307:637) suggested AB associated with three fold higher mortality • Therapy had no protective effect • AB seems to be a marker of debility • More recent comparative studies confirm no benefit from Rx and no higher mortality in non Rx

  19. Case Presentation • 91 year old woman admitted from NH with fever, altered mental state and drainage from recent hip incision, no urinary sx • Urine culture from cath inserted in ER: >100,000 Pseudomonas aeruginosa • Diagnosis: “Urosepsis” • BUT

  20. Case continued • Blood and hip aspirate cultures: MRSA • No response to anti-pseudomonas Rx: still confused • Woke up with Vancomycin • Diagnoses: • Infected total hip with secondary bacteremia – MRSA • Asymptomatic bacteriuria - Pseudomonas

  21. Fever and UTI in Elderly Institutionalized • Prospective study • Jan 1, 1989 through Dec 31, 1990 • Two LTCF in Canada • Demographics • M:F 3:1 • Majority >65 years • Catheters 5.7% to 9.3% Nicolle, AJM 1996; 100:71.

  22. Fever and UTI in Elderly Institutionalized • Entry Criteria – Fever • Urine cultures, UA at enrollment and Q4 weeks • Monitored serum antibody • Major Outer Membrane Protein (MOMP) of E coli for all enterobacteriaceae • IgG to other organisms

  23. Fever and UTI in Elderly Institutionalized: Definitions • Fever >38 (100.4) • Sx UTI for non cath required at least 3: • Fever or chills* • New or increased lower tract irritation • New flank or suprapubic pain or tender • Change in character of urine • Worsening mental status* • *our case

  24. Definitions continued • Indwelling catheter: two symptoms • Fever or chills • New flank or suprapubic pain/tender • Change in character of urine • Worsening mental status • Bacteriuria • Non cath >= 100,000/ml of one or two bugs • Condom cath >=100,000 of <3 bugs • Cath: any number

  25. Febrile Morbidity in long term care patients • Prevalence of bacteriuria - 50% • <10% were catheterized • Positive Predictive Value of bacteriuria for clinical UTI – 11% • PPV of bacteriuria for serologic UTI – 12% • <10% of episodes of unexplained fever were attributable to UTI • Nicolle, AJM 1996; 100:71.

  26. To Summarize • Bacteriuria very common in uncatheterized long term care patients • Poor correlation of bacteriuria with symptoms attributable to urinary tract • Bacteriuria rarely explains fever in absence of localizing symptoms • Most treatment for AB is inappropriate

  27. Should AB ever be treated? • Pregnant women • AB Prevalence: 4-7% • Optimal time to screen is 16th week • Symptomatic infection develops in 20-40% of those with AB (1-3% of all pregnancies) • Premature labor in 20-50% with symptomatic UTI • Successful Rx of AB reduces rate of symptomatic UTI by 80-90% • Patterson TF, Andriole VT. Inf Dis Clin NA 1997;11:593-608

  28. When to Rx AB – cont’d • Prior to renal transplant • Prior to invasive urinary procedures • TURP, biopsy prostate • not insertion of catheter (except if valvular heart disease and infected urine) • Unclear before insertion of non urinary prosthesis: heart valve, total hip or knee

  29. Case Presentation 2 • 39 woman, 250 pounds, three previous THR. No urinary sx. • Pre op: “dirty” voided UC: 30k E coli and Klebsiella • Three days of Cefamandole and Tobra starting at time of surgery • 6 weeks later, E coli in hip • Different biotypes and MIC’s

  30. Case 2 - continued • She sued the surgeon alleging negligence for replacing hip in setting of positive urine culture • Defense expert testified • the two organisms were unrelated • the literature didn’t support any increased risk of SSI from asymptomatic UTI*

  31. *Review of literature on urine cultures prior to hip surgery • Lawrence, Kroenke. Arch Int Med 1988; 148:1370-1373 • Chart review 200 consecutive knee procedures • Excluded insertion of prostheses • Criteria for abnormal UA established • 10% UA’s indicated, 90% not • SSI: 1/166 with normal UA; 0/23 with WBC • Overall infection rate 0.5% (95% CI: 0-2.3%)

  32. Literature - continued • Health Technology Assessment 1997; 1:43-47 • No controlled trials on value of routine preop urine testing • Routine preop urine abnormal 1%-34.1% • Leads to change in management in only 0.1%-2.8%! • No good evidence that preop abnormal UA is associated with any postop complication

  33. Case - continued • Plaintiff’s expert stated “An E coli is an E coli is an E coli. Don’t bother me with genetics.” • SHE WON THE CASE!

  34. Catheter Associated UTI • Short term catheter <30 days • Long term catheter >30 days • Prevention of bacteriuria • Prevention of complications of bacteriuria • Avoidance of urethral catheters Warren Inf Dis Clin NA 1997; 11: 609-622

  35. How Significant is Pyuria in Foley Urine? • Definition • Standard: 5 WBC/hpf • Hemocytometer: 10 WBC/µl • Does not correlate with catheter related symptomatic infection. • SHOULD NOT BE USED AS REASON TO OBTAIN FOLEY URINE CULTURE • Tambyah, Maki. Arch Int Med 2000; 160: 673

  36. Short Term Catheter • 15-25% of acute care patients have catheter • Mean/median duration between 2 and 4 days • At 3% to 10% incidence/day, 10% to 30% will develop catheter associated bacteriuria (CAB) during their hospital stay • Warren Inf Dis Clin NA 1997; 11: 609-622

  37. Risk Factors for CAB Platt. Am J Epid 1986; 124: 977 • Duration of catheter • Absence of urinometer • Colonization of drainage back/back flow • Diabetes • No receipt of antibiotics • Female • For other than surgery or output measures • Abnormal serum creatinine • Errors in catheter care

  38. Complications of Short Term Catheter • Most episodes of AB are asymptomatic • Fever or UTI sx in up to 30% • <5% associated with bacteremia • Attributable mortality <15% of bacteremic • Given large number of short term catheters nationwide, up to 15% of nosocomial bacteremias are from UTI

  39. PHD 2001 SurveyData courtesy of Sharon Williamson, MT(ASCP) and Bobby Moore, MT (ASCP) PHD Microbiology Lab • Review Micro Lab Computer for • All patients with positive urinary catheter culture and • Positive blood cultures drawn same day • Exclude urine positive for Staph aureus and Candida since • Literature states these are more likely causes of the bacteriuria rather than the consequence

  40. Cases with same isolate in BC/UC • Total 19 cases • 14 E coli • 2 Proteus mirabilis • 1 had three other urinary isolates as well • 2 Klebsiella pneumoniae • 1 Morganella morganii

  41. Cases with different isolates • 55 total cases • Skin flora in blood: 40 • Seven had 2 + BC for CNS – likely pathogens • 33 had single + BC – unclear significance • Definite pathogens in blood: 16 • Combined definite and likely: 23 cases

  42. Likelihood of Positive Foley Culture As Cause of “urosepsis” • 19/42 (45%) bacteremic episodes in this cohort of catheterized patients were attributable to urine isolate • 23/42 (55%) bacteremic episodes not related to urine isolate – would have been missed if therapy based on urine only!

  43. Conclusion • In an acute care hospital, cannot assume that a positive urine culture from catheterized patient is the cause of a febrile episode • Must always draw blood culture before initiating therapy • Keep an open mind about other sites for fever

  44. Long Term Catheters • Prevalence: more than 100,000 NH patients in USA • Incidence of bacteriuria still 3% to 10%/day • At 30 days, almost 100% prevalence! • 95% polymicrobial • Catheter bugs not the same as bladder bugs at least 25% of the time (biofilm theory)

  45. Complications of Long Term Catheters • Two thirds of febrile episodes in aged LTC attributed to UTI • Incidence: one febrile episode per 100 catheter days • MOST SELF LIMITED (<1 day) • Therapy not usually indicated

  46. Other Complications of LTC • Catheter obstruction • Related to biofilm production • Infection stones • Chronic renal inflammation • Chronic pyelo usually only with obstruction/stones • Urethritis/fistulae, epididymitis, prostatitis • Bladder cancer

  47. Prevention of CA Bacteriuria • Closed catheter system • Remove catheter when possible • Delay onset • Coated catheters largely ineffective • Systemic antibiotics work but ultimately • Adverse effects • Multidrug resistant isolates emerge

  48. Prevent Complications of CA Bacteriuria? • Search out and treat AB? • Prospective trial (Warren JAMA 1982;248:454) • no effect on preventing fever • Marked increase in resistance • DO NOT TREAT CAB except in • epidemics or clusters • High risk patients • Pregnancy, renal transplant, urologic surgery

  49. What about symptomatic UTI in catheterized patient? • Always look for non-UTI explanations as well • Blood cultures • Treat with specific therapy for 10-14 days assuming occult pyelonephritis • Change catheter and obtain new culture before Rx • Clinical and bacteriologic outcomes better • More reliable culture from newly inserted catheter with no biofilm • Raz. J Urol 2000;164:1254

More Related