Screening for asymptomatic subjects is deemed appropriate if bacteriuria is associated with preventable adverse outcomes such as symptomatic urinary infection, progression to chronic kidney disease or hypertension, development of urinary tract cancer, and decreased duration of survival.
Screening for asymptomatic subjects is deemed appropriate if bacteriuria is associated with preventable adverse outcomes such as symptomatic urinary infection, progression to chronic kidney disease or hypertension, development of urinary tract cancer, and decreased duration of survival.<ref name="pmid15714408">{{cite journal| author=Nicolle LE, Bradley S, Colgan R, Rice JC, Schaeffer A, Hooton TM et al.| title=Infectious Diseases Society of America guidelines for the diagnosis and treatment of asymptomatic bacteriuria in adults. | journal=Clin Infect Dis | year= 2005 | volume= 40 | issue= 5 | pages= 643-54 | pmid=15714408 | doi=10.1086/427507 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15714408 }} </ref>
Asymptomatic bacteriuria is a condition in which a significant number of bacteria appear in the urine occurring without typical symptoms such as burning during urination or frequent urination.[1]
Definitions
Asymptomatic bacteriuria is defined as isolation of a specified quantitative count of bacteria in an appropriately collected urine specimen obtained from a person without symptoms or signs referable to urinary infection.[2]
Historical Perspective
In 1950's, Kass et al. proposed a quantitative culture method for the microbiologic diagnosis of urinary tract infections. About 105 bacteria per milliliter must be present in the urine specimen to be consistently read as positive, which is seen in 95% of samples from patients with pyelonephritis.[3][4]
Epidemiology
Bacteriuria is commonly found in certain populations with variable prevalence including pregnant women,[5] elderly people,[5]diabetics,[6] patients with spinal cord injuries,[7][8] patients undergoing hemodialysis,[9] patients with indwelling urethral catheters, and patients with genitourinary abnormalities.[10]
Pathophysiology
Microbiology
Host Factors
Screening
Screening for asymptomatic subjects is deemed appropriate if bacteriuria is associated with preventable adverse outcomes such as symptomatic urinary infection, progression to chronic kidney disease or hypertension, development of urinary tract cancer, and decreased duration of survival.[11]
Diagnosis
Laboratory Findings
Pyuria
Pyuria is defined as increased numbers of polymorphonuclear leukocytes in the uirne and is evidence of an inflammatory response in the urinary tract.[12] An operational definition of pyuria is the presence of ≥15 leukocytes per 400x microscopic field in the sediment of first-void urine. Although pyuria is prevalent among people with asympatomatic bacteriuria,[7][13][14][15][16] its presence or degree has not been shown to correlate with the prognosis and should not affect clinical decisions about antibiotics.[17][18][19] Pyuria accompanying asymptomatic bacteriuria is not an indication for antimicrobial treatment.[11]
Diagnostic Criteria
The diagnosis of bacteriuria in an asymptomatic individual is based on the culture results of urine collected in a manner that minimizes the possibility of contamination and limits the period between sampling and testing the specimen which avoids false positivity due to bacterial growth).
The quantitative definition for significant bacteriuria is:[20]
For asymptomatic women, bacteriuria is defined as 2 consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts of ≥105 cfu/mL.
A single, clean-catch, voided urine specimen with 1 bacterial species isolated in a quantitative count of ≥105 cfu/mL identifies bacteriuria in asymptomatic men.
A single catheterized urine specimen with 1 bacterial species isolated in a quantitative count of ≥102 cfu/mL identifies bacteriuria in women or men.
No screening or treatment recommended for healthy, bacteriuric women.
Although asymptomatic bacteriuria increases the risk of urinary tract infection but has no effect on the long term adverse outcomes like CKD, genitourinary cancer or overall survival.[28][23]
Studies' results indicated that the treatment wouldn't decrease the frequency for asymptomatic bacteriuria or the risk of developing symptomatic urinary tract infection.[29]
The duration of antimicrobial therapy is 3-7 days.
After therapy of recurrent bacteriuria, periodic screening should be considered.
Diabetic Women
Asymptomatic bacteriuria screening or treatment is not recommended for diabetic women.
No change in the rate of symptomatic urinary tract infection, diabetes progression and complication or overall mortality in diabetic women[36][37], in addition to the adverse effects of antimicrobial therapy.[18]
Older Persons Residing in the Community
Routine screening and treatment for asymptomatic bacteriuria is not indicated.
Treatment has no effect on decreasing symptomatic urinary tract infections,[38] adverse outcomes or survival.[39][40]
Elderly Institutionalized Subjects
No recommendation for screening for or treatment of asymptomatic bacteriuria.
No reduction in rates of symptomatic infections or survival.[41][42]
Instead, treatment has increased the risk of adverse effects and reinfections with resistant strains.[41]
Subjects with Spinal Cord Injuries
No benefit from screening for or treatment of asymptomatic bacteriuria
Although the high prevalence of asymptomatic bacteriuria in patients with spinal cord injuries[43], but antimicrobial therapy harm outweigh benefit because of recurrent infections with more resistant strains.[8]
Patients with Indwelling Urethral Catheters
It is not recommended to screen for or treat asymptomatic bacteriuria or fungiuria for short or long term catheters,[44] but antimicrobial therapy can be used for women with persistent bacteriuria 48 hours after removal of the urethral catheter.
No benefit of therapy of asymptomatic bacteriuria due to similar recurrence rates with more resistance to antibiotics.[45][46]
Significant improvement has been shown with women treated for bacteriuria that existed 48 hours after removal of indwelling urethral catheters.[47]
Due to high risk of bacteremia (60%) and sepsis(6-10%) because of traumatic genitourinary procedures,[48] and the effectiveness of antimicrobials to prevent these complications;[49][48][50]screening for bacteriuria and antimicrobial therapy is recommended before the initiation of invasive urologic procedures like transurethral resection of prostate.[49][50]
Antibiotic therapy usually discontinued after the procedure, unless there is an indwelling urethral catheter until removed. [48][49]
Immunocompromised Patients and Other Patients
Poor transplant prognosis and complications hasn't been associated with asymptomatic bacteriuria,[51][52]so there is no benefit from screening[53][54]
for or treatment of asymptomatic bacteriuria in renal transplant or other solid organ[55] transplant patients.[11]
↑Rubin, RH.; Shapiro, ED.; Andriole, VT.; Davis, RJ.; Stamm, WE. (1992). "Evaluation of new anti-infective drugs for the treatment of urinary tract infection. Infectious Diseases Society of America and the Food and Drug Administration". Clin Infect Dis. 15 Suppl 1: S216–27. PMID1477233. Unknown parameter |month= ignored (help)
↑KASS, EH. (1956). "Asymptomatic infections of the urinary tract". Trans Assoc Am Physicians. 69: 56–64. PMID13380946.
↑KASS, EH. (1957). "Bacteriuria and the diagnosis of infections of the urinary tract; with observations on the use of methionine as a urinary antiseptic". AMA Arch Intern Med. 100 (5): 709–14. PMID13468815. Unknown parameter |month= ignored (help)
↑ 5.05.1Nicolle, LE. (2003). "Asymptomatic bacteriuria: when to screen and when to treat". Infect Dis Clin North Am. 17 (2): 367–94. PMID12848475. Unknown parameter |month= ignored (help)
↑Zhanel, GG.; Harding, GK.; Nicolle, LE. "Asymptomatic bacteriuria in patients with diabetes mellitus". Rev Infect Dis. 13 (1): 150–4. PMID2017615.
↑ 7.07.1Nicolle, LE. (1997). "Asymptomatic bacteriuria in the elderly". Infect Dis Clin North Am. 11 (3): 647–62. PMID9378928. Unknown parameter |month= ignored (help)
↑ 8.08.1Waites, KB.; Canupp, KC.; DeVivo, MJ. (1993). "Epidemiology and risk factors for urinary tract infection following spinal cord injury". Arch Phys Med Rehabil. 74 (7): 691–5. PMID8328888. Unknown parameter |month= ignored (help)
↑Bakke, A.; Digranes, A. (1991). "Bacteriuria in patients treated with clean intermittent catheterization". Scand J Infect Dis. 23 (5): 577–82. PMID1767253.
↑Chaudhry, A.; Stone, WJ.; Breyer, JA. (1993). "Occurrence of pyuria and bacteriuria in asymptomatic hemodialysis patients". Am J Kidney Dis. 21 (2): 180–3. PMID8430679. Unknown parameter |month= ignored (help)
↑Stamm, WE. (1983). "Measurement of pyuria and its relation to bacteriuria". Am J Med. 75 (1B): 53–8. PMID6349345. Unknown parameter |month= ignored (help)
↑Hooton, TM.; Scholes, D.; Stapleton, AE.; Roberts, PL.; Winter, C.; Gupta, K.; Samadpour, M.; Stamm, WE. (2000). "A prospective study of asymptomatic bacteriuria in sexually active young women". N Engl J Med. 343 (14): 992–7. doi:10.1056/NEJM200010053431402. PMID11018165. Unknown parameter |month= ignored (help)
↑Zhanel, GG.; Nicolle, LE.; Harding, GK. (1995). "Prevalence of asymptomatic bacteriuria and associated host factors in women with diabetes mellitus. The Manitoba Diabetic Urinary Infection Study Group". Clin Infect Dis. 21 (2): 316–22. PMID8562738. Unknown parameter |month= ignored (help)
↑Bachman, JW.; Heise, RH.; Naessens, JM.; Timmerman, MG. (1993). "A study of various tests to detect asymptomatic urinary tract infections in an obstetric population". JAMA. 270 (16): 1971–4. PMID8411555. Unknown parameter |month= ignored (help)
↑KINCAID-SMITH, P.; BULLEN, M. (1965). "BACTERIURIA IN PREGNANCY". Lancet. 1 (7382): 395–9. PMID14238090. Unknown parameter |month= ignored (help)
↑Geerlings, SE.; Stolk, RP.; Camps, MJ.; Netten, PM.; Collet, JT.; Schneeberger, PM.; Hoepelman, AI. (2001). "Consequences of asymptomatic bacteriuria in women with diabetes mellitus". Arch Intern Med. 161 (11): 1421–7. PMID11386891. Unknown parameter |month= ignored (help)
↑Semetkowska-Jurkiewicz, E.; Horoszek-Maziarz, S.; Galiński, J.; Manitius, A.; Krupa-Wojciechowska, B. "The clinical course of untreated asymptomatic bacteriuria in diabetic patients--14-year follow-up". Mater Med Pol. 27 (3): 91–5. PMID8935144.
↑Boscia, JA.; Kobasa, WD.; Knight, RA.; Abrutyn, E.; Levison, ME.; Kaye, D. (1987). "Therapy vs no therapy for bacteriuria in elderly ambulatory nonhospitalized women". JAMA. 257 (8): 1067–71. PMID3806896. Unknown parameter |month= ignored (help)
↑Nordenstam, GR.; Brandberg, CA.; Odén, AS.; Svanborg Edén, CM.; Svanborg, A. (1986). "Bacteriuria and mortality in an elderly population". N Engl J Med. 314 (18): 1152–6. doi:10.1056/NEJM198605013141804. PMID3960089. Unknown parameter |month= ignored (help)
↑Heinämäki, P.; Haavisto, M.; Hakulinen, T.; Mattila, K.; Rajala, S. (1986). "Mortality in relation to urinary characteristics in the very aged". Gerontology. 32 (3): 167–71. PMID3721209.
↑ 41.041.1Nicolle, LE.; Mayhew, WJ.; Bryan, L. (1987). "Prospective randomized comparison of therapy and no therapy for asymptomatic bacteriuria in institutionalized elderly women". Am J Med. 83 (1): 27–33. PMID3300325. Unknown parameter |month= ignored (help)
↑Abrutyn, E.; Mossey, J.; Berlin, JA.; Boscia, J.; Levison, M.; Pitsakis, P.; Kaye, D. (1994). "Does asymptomatic bacteriuria predict mortality and does antimicrobial treatment reduce mortality in elderly ambulatory women?". Ann Intern Med. 120 (10): 827–33. PMID7818631. Unknown parameter |month= ignored (help)
↑Erickson, RP.; Merritt, JL.; Opitz, JL.; Ilstrup, DM. (1982). "Bacteriuria during follow-up in patients with spinal cord injury: I. Rates of bacteriuria in various bladder-emptying methods". Arch Phys Med Rehabil. 63 (9): 409–12. PMID7115037. Unknown parameter |month= ignored (help)
↑Sobel, JD.; Kauffman, CA.; McKinsey, D.; Zervos, M.; Vazquez, JA.; Karchmer, AW.; Lee, J.; Thomas, C.; Panzer, H. (2000). "Candiduria: a randomized, double-blind study of treatment with fluconazole and placebo. The National Institute of Allergy and Infectious Diseases (NIAID) Mycoses Study Group". Clin Infect Dis. 30 (1): 19–24. doi:10.1086/313580. PMID10619727. Unknown parameter |month= ignored (help)
↑Lyerová, L.; Lácha, J.; Skibová, J.; Teplan, V.; Vítko, S.; Schück, O. (2001). "Urinary tract infection in patients with urological complications after renal transplantation with respect to long-term function and allograft survival". Ann Transplant. 6 (2): 19–20. PMID11803612.
↑Ghasemian, SM.; Guleria, AS.; Khawand, NY.; Light, JA. (1996). "Diagnosis and management of the urologic complications of renal transplantation". Clin Transplant. 10 (2): 218–23. PMID8664523. Unknown parameter |month= ignored (help)
↑Kasiske, BL.; Vazquez, MA.; Harmon, WE.; Brown, RS.; Danovitch, GM.; Gaston, RS.; Roth, D.; Scandling, JD.; Singer, GG. (2000). "Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation". J Am Soc Nephrol. 11 Suppl 15: S1–86. PMID11044969. Unknown parameter |month= ignored (help)