Year: 2011
Type: book-chapter
Abstract: Urinary Tract Infections 92 Historical aspectsThe use of quantitative urine cultures for the microbiological diagnosis of UTI was suggested and validated more than 50 years ago (Kass, 1957(Kass, , 1962)).If bacteria were isolated in quantitative counts of ≥10 5 colony-forming units (CFU)/mL in a voided urine specimen from asymptomatic patients, the condition was described as asymptomatic bacteriuria.Interestingly, in this patient population the isolated organisms were always the same in paired specimens obtained by urinary catheterization.Quantitative counts of ≤10 5 colonyforming units (CFU)/mL in a voided urine specimen usually resulted in a negative paired catheterized specimens.Therefore, ≤10 5 colony-forming units (CFU)/mL in voided specimens were considered as contamination.The general acceptance and widespread use of this technique identified several clinically asymptomatic patient populations with an increased prevalence of positive urine cultures (Kunin, 1966).Specifically, pregnant women, patients with urogenital abnormalities, and patients with indwelling urethral catheters demonstrated a higher incidence of asymptomatic bacteriuria (Kunin, 1966).Antibiotic treatment of asymptomatic bacteriuria in pregnant women resulted in a significantly reduced incidence of pyelonephritis (Kass, 1962), which is considered an important concern in pregnancy.The obvious benefits of eradicating bacteriuria in asymptomatic pregnant women were interpreted to be generally applicable.Therefore, other patient populations with asymptomatic bacteriuria were also treated ordinarily (Kass, 1962).This treatment strategy was not based on clinical studies or facts, rather on the assumption that asymptomatic bacteriuria was consistently harmful in all populations and necessitated antibiotic treatment (Nicolle, 2006).Both basic and clinical research conducted over the last few decades, including long-term cohort studies and prospective randomized comparative trials in defined populations with asymptomatic bacteriuria, have improved the understanding of this clinical condition and addressed appropriate management (Nicolle, 2006). Material and methodsTo identify all relevant materials, comprehensive literature searches were performed via the data sources: MEDLINE, EMBASE, CINAHL and OVID using the key words: asymptomatic bacteriuria, pyuria, urinary tract infection, urine culture, UTI, antibiotic treatment.Relevant articles and references between 1962 and 2010 were reviewed and analyzed for data on the association between asymptomatic bacteriuria and antibiotic treatment.Reference lists from relevant review articles were also searched.Only articles published as formal papers in peer-reviewed journals were selected for inclusion if they reported outcomes of interest including potential benefits of antibiotic treatment for asymptomatic bacteriuria.The data base searches resulted in 1400 articles, of which 356 of 1400 pertained directly to asymptomatic bacteriuria and antibiotic treatment.The entirety of these articles was reviewed, forming the basis for the current review. Results Causes and pathogenesis of asymptomatic bacteriuriaThe normal upper and lower urinary tract is considered sterile, except for the distal end of the urethra.Colonization with bacteria or development of an asymptomatic bacteriuria occurs due to ascension of bacteria into the urinary bladder or into the upper urinary tract, www.intechopen.com
Source: InTech eBooks
DOI: 10.5772/23734
Authors: Thomas Nelius, Stephanie Filleur, Jonathan S.
Institution: Texas Tech University Health Sciences Center
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W1540445472