Define bacteriuria and when is it significant

Dis Mon 49 : 71 — Ronald A Ludwig E Urinary tract infections in adults with diabetes. Int J Antimicrob Agents 17 : — Clin Infect Dis 15 suppl 1 : S — S Sakai Y Low-count organisms concealed by dominant uropathogenic organisms in urine of patients with asymptomatic bacteriuria. Salvador E Wagenlehner F Kohler CD Mellmann A Hacker J Svanborg C Dobrindt U Comparison of asymptomatic bacteriuria Escherichia coli isolates from healthy individuals versus those from hospital patients shows that long-term bladder colonization selects for attenuated virulence phenotypes.

Infect Immun 80 : — Schnarr J Smaill F Asymptomatic bacteriuria and symptomatic urinary tract infections in pregnancy. Eur J Clin Invest 38 suppl 2 : 50 — BMC Microbiol 11 : Smaill F Antibiotics for asymptomatic bacteriuria in pregnancy. Sunden F Hakansson L Ljunggren E Wullt B Bacterial interference—is deliberate colonization with Escherichia coli an alternative treatment for patients with recurrent urinary tract infection?

J Clin Microbiol 46 : — BMC Infect Dis 12 : J Clin Microbiol 47 : — Curr Opin Microbiol 16 : — Preventive Services Task Force U Screening for asymptomatic bacteriuria in adults: reaffirmation recommendation statement.

Drugs Aging 22 : — A review. Neurourol Urodyn 30 : 32 — Urogynaecologia 25 : e4 , 11— Clin Infect Dis 38 : — Woodford HJ Graham C Meda M Miciuleviciene J Bacteremic urinary tract infection in hospitalized older patients-are any currently available diagnostic criteria sensitive enough?

J Am Geriatr Soc 59 : — Wullt B The role of P fimbriae for Escherichia coli establishment and mucosal inflammation in the human urinary tract. Int J Antimicrob Agents 21 : — Additional Supporting Information may be found in the online version of this article:. Table S1. ABU prevalence, risk factors and comorbidities in distinct patient populations shown alongside specific prevalence rates of causal microorganisms. Oxford University Press is a department of the University of Oxford.

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Volume Article Contents Abstract. Introduction: bacteriuria in asymptomatic and symptomatic urinary tract infection. Prevalence of ABU causal microorganisms in distinct patient populations. Etiology of ABU in pregnancy, diabetes, and elderly individuals. Current controversy: etiology of bacteriuria in women with urge incontinence. What factors influence the progression of bacteriuria? Advances in diagnostics: emerging molecular detection methods.

Conclusions and future directions. Supporting Information. Asymptomatic bacteriuria: prevalence rates of causal microorganisms, etiology of infection in different patient populations, and recent advances in molecular detection. Ipe , Deepak S.

Oxford Academic. Lana Sundac. William H. Benjamin, Jr. Kate H. Glen C. Correspondence: Glen C. Editor: Mark Schembri. Revision received:. Cite Cite Deepak S. Select Format Select format. Permissions Icon Permissions. Abstract Bacteriuria, or the presence of bacteria in urine, is associated with both asymptomatic and symptomatic urinary tract infection and underpins much of the dynamic of microbial colonization of the urinary tract.

Open in new tab. Open in new tab Download slide. Diagnosis of bacteriuria by detection of volatile organic compounds in urine using an automated headspace analyzer with multiple conducting polymer sensors. Google Scholar Crossref. Search ADS. Does asymptomatic bacteriuria predict mortality and does antimicrobial treatment reduce mortality in elderly ambulatory women? Untreated asymptomatic group B streptococcal bacteriuria early in pregnancy and chorioamnionitis at delivery.

Measurement of urinary lactoferrin as a marker of urinary tract infection. Google Scholar PubMed. Delay in the diagnosis of bacteraemic urinary tract infection in elderly patients. Rapid detection of urinary tract infections using isotachophoresis and molecular beacons. Use of flow cytometry Sysmex UF to screen for positive urine cultures: in search for the ideal cut-off. Screening for urinary tract infection with the Sysmex UFi urine flow cytometer.

Long-term Escherichia coli asymptomatic bacteriuria among women with diabetes mellitus. The urine dipstick test useful to rule out infections. Diagnostic challenges and opportunities in older adults with infectious diseases. Bacteriuria screening by automated whole-field-image-based microscopy reduces the number of necessary urine cultures. Dapagliflozin monotherapy in type 2 diabetic patients with inadequate glycemic control by diet and exercise: a randomized, double-blind, placebo-controlled, phase 3 trial.

Integrated next-generation sequencing of 16S rDNA and metaproteomics differentiate the healthy urine microbiome from asymptomatic bacteriuria in neuropathic bladder associated with spinal cord injury. Other outcomes such as CDI and antimicrobial resistance were not reported. The impact of treatment vs no treatment of ASB on death, permanent institutionalization, or functional decline was assessed in patients with and without delirium.

In 68 delirious patients in whom ASB was treated, there was no significant functional recovery when compared to 22 patients without treatment unadjusted RR, 1. Delirium tends to have a fluctuating course. Careful observation of patients with delirium and evaluation for other contributing factors, such as dehydration, is a strategy for reducing unnecessary antimicrobial use for bacteriuria [95].

It is unknown whether antimicrobial therapy for ASB in patients with delirium is beneficial when fever or other systemic signs of infection are present and no other localizing source of infection is apparent []. For older patients with severe clinical presentations consistent with sepsis syndrome and for whom an alternate infection site is not apparent, institution of empiric antimicrobial therapy effective for potential UTI, as well as other sites of infection, may be appropriate pending culture results.

Falls are common among older populations who also have a high prevalence of ASB, and often lead to a diagnosis of UTI and initiation of antimicrobial therapy, in the absence of consistent genitourinary symptoms or systemic signs of infection such as fever or change in hemodynamic status.

Whether these patients had symptoms of urgency or frequency that contributed to a fall on the way to the toilet is not documented. These studies suggest that most older residents who fall do not have ASB and falls should not immediately trigger suspicion for UTI; other causes are much more likely. Bacteriuria is usually unrelated and simply a confounding factor.

Neither of these studies directly addresses whether antimicrobial therapy of bacteriuria in residents who have had a fall and do not have genitourinary symptoms or systemic signs of infection modifies adverse outcomes such as sepsis or death, so the evidence base is rated as low quality.

However, taken together with evidence that the treatment of ASB in patients without minimal criteria for UTI is not associated with any demonstrable benefits and antimicrobials have an important risk of harm, the panel believed that the adverse consequences of antimicrobial therapy almost certainly outweigh any desirable consequences of therapy in patients who have fallen and have ASB. In patients who fall and have fever or hemodynamic instability, careful evaluation to identify a site of infection is warranted.

We make a strong recommendation because there is high certainty for harm and low certainty of any benefit from treatment of ASB in older adults. Current evidence does not suggest a causal relationship between bacteriuria and presentations without classic localizing UTI symptoms, such as changes in mental status or falls.

Treatment of ASB in patients with delirium has not been shown to have any beneficial impact in clinical outcomes compared to no treatment, including reducing severity or duration of delirium and reducing risk of sepsis, death, or hospitalizations all low or very low certainty.

There is high certainty that antimicrobials cause harm. Treatment probably increases the risk of antibiotic-associated diarrhea, including CDI, and increases the risk of antimicrobial resistance for the individual patient, the institution, and the community [87, 88, ].

This recommendation places a high value on avoiding adverse outcomes of antimicrobial therapy in the functionally impaired older individual in the absence of evidence that such treatment is beneficial. Since bacteriuria is often detected and treated in patients with delirium or falls, further studies—ideally randomized—to evaluate the risks and benefits of antimicrobial treatment and determine if there is any improvement in mental status, frequency of repeat falls, or benefits in nonlocalizing clinical signs and symptoms, should be undertaken.

The updated literature review looked for RCTs that compared antimicrobial therapy to no antimicrobial therapy in patients with ASB and diabetes. We did not identify any new studies to inform this recommendation. The previous recommendation against treating women with diabetes who had ASB was based on 1 RCT [22] and 2 prospective cohort studies [, ]. The randomized trial compared antimicrobial therapy or no therapy for women with diabetes and ASB, and the prospective cohort studies compared outcomes among patients initially with and without ASB.

Rates of pyelonephritis were also not significantly different between the antimicrobial and placebo groups 0. Antimicrobial use for symptomatic UTI, prophylaxis, or other infections was significantly more common in the treatment group.

These subjects received nearly 5 times more days of antimicrobial therapy than the control group. In the prospective cohort studies [—], there were no between-group differences in the outcomes of symptomatic UTI, progression to diabetic complications, and mortality. Among the prespecified subgroups of interest gender, type 1 vs type 2 diabetes, and poorly controlled vs well-controlled diabetes there was no evidence to inform specific recommendations.

Antimicrobials may not reduce the risk of symptomatic urinary infection, including pyelonephritis in people with diabetes and ASB. Men with diabetes were included in only 1 cohort study and outcomes were similar. There is high-quality evidence that antimicrobials increase the risk of adverse effects. Based on the lack of demonstrated benefit and the possible harms that occur with additional antimicrobial use, we recommend against screening for or treating ASB in persons with diabetes.

There is a subgroup of diabetic women who experience a high frequency of recurrent symptomatic UTI [22]. Further studies to characterize these high-risk women and describe predictors and outcomes of ASB and efficacy of antimicrobial treatment would be warranted.

Randomized trials of treatment or nontreatment of ASB in diabetic men are needed. ASB is common following renal transplantation, and symptomatic UTI is the most frequent infection identified in these patients [, ]. Unique outcomes of concern potentially attributable to UTI include graft loss, acute graft rejection, and impaired long-term graft function. The impact of UTI may be more severe in the immediate posttransplant period ie, within the first month , when patients are at highest risk for infectious complications because of exposures to new and more intensive immunosuppressive therapy, indwelling urologic devices, and urologic interventions.

Prophylactic antimicrobial therapy, usually TMP-SMX, is routinely used for the prevention of Pneumocystis jirovecii pneumonia during the initial 6 months following renal transplant. Renal transplant patients with ASB have an increased frequency of symptomatic UTI, including pyelonephritis [16, —]. These include female sex, comorbidities, urologic variables, and some immunosuppressive therapies. Retrospective studies, most of which do not differentiate ASB and symptomatic UTI, have reported associations of early, but not late, graft pyelonephritis with graft loss [—], pyelonephritis with decreased long-term creatinine clearance [, ], and late UTI with graft loss [].

Other studies report no adverse outcomes attributable to UTI for either early [] or long-term [, —] graft survival or renal function. More than one-half of positive cultures were identified in the first month after transplantation, when screening was most frequent.

All episodes of bacteriuria were treated with antimicrobials. ASB was not associated with poorer graft function. Two retrospective comparative cohort studies report no association of untreated ASB with poorer outcomes in renal transplant recipients [, ]. El-Amari et al [] identified episodes of asymptomatic E. Only 1 untreated patient progressed to symptomatic infection with the same organism.

There were no episodes of acute graft rejection observed in either group. Green et al [] evaluated a single episode of ASB identified in patients from 1 to 12 months after transplantation; Other outcomes, including changes in serum creatinine, graft loss, pyelonephritis, or urosepsis were similar for treated and untreated patients.

These retrospective studies are subject to confounding, however, as physicians would, presumably, be more likely to treat patients with a positive urine culture if they were judged to have a poorer clinical status. Two prospective, randomized, open-label comparative trials evaluated treatment or nontreatment of ASB following renal transplant.

Moradi et al [] enrolled 88 patients at least 1 year after transplant, who were then followed for 9—12 months. Patients with Proteus mirabilis infection were excluded. Outcomes of bacteriuric episodes, symptomatic UTI, and renal function were similar between treated and nontreated subjects. The report does not describe criteria used for identification of symptomatic episodes. Urine was screened for bacteriuria every 2 weeks for the first 3 months after transplantation, monthly to the first year, and every 1—3 months thereafter.

Regimens for treatment of recurrent episodes varied for reinfection or relapse. Outcomes were analyzed as intention to treat and per protocol. The primary outcome of acute pyelonephritis occurred with equal frequency in both groups in all analyses.

There were also no differences in any of the secondary outcomes of long-term 12—24 months graft function, all-cause mortality, cumulative incidence of lower UTI, acute graft rejection, CDI, colonization or infection due to multidrug-resistant bacteria, and graft loss by the end of the follow-up period. Only 16 3. Of the 9 episodes of pyelonephritis in subjects in the intention-to-treat analysis, 3 were not preceded by ASB with the same organism, 3 were preceded by bacteriuria with a time interval too short to allow treatment, and 2 were preceded by bacteriuria recognized over 40 days before pyelonephritis, so a causal link could not be presumed.

Thus, no benefits of treatment of ASB were identified. This study is also evidence of the limited feasibility of consistently identifying and treating all episodes of bacteriuria as a strategy to maintain a sterile urine in renal transplant recipients. Consistent identification of episodes of ASB in renal transplant patients requires frequent screening as ASB commonly recurs. Antimicrobial-resistant organisms are common in renal transplant recipients, and a high proportion of resistant organisms causing ASB may not be effectively treated with oral therapy.

Treatment of ASB probably promotes reinfection with organisms increasingly resistant to antimicrobials, potentially compromising treatment of symptomatic UTI, which is also frequent in these patients.

There is also high-quality evidence that antimicrobial therapy has an important risk of adverse effects. There may be subgroups of transplant recipients at higher risk for developing pyelonephritis indwelling devices, combined transplant. Further evaluation of these patients and whether proactive management of ASB can prevent pyelonephritis is worthy of additional study.

In addition, the efficacy and practicality of screening for and treatment of ASB within 1 month of transplantation needs to be evaluated given the higher risk for infection and complications from infection in the early posttransplant period. No studies were identified which addressed the question of treatment or nontreatment of ASB in SOT patients other than renal transplant recipients.

As with renal transplants, most nonrenal transplant recipients receive prophylactic antimicrobial therapy to prevent infections for the initial 6 months following transplantation.

A prospective registry study reported that the incidence of symptomatic UTI per patient-days for patients with at least 1 year of follow-up was 0. ASB was not reported.

After 6 months, rates of genitourinary infection per days, excluding uncomplicated cystitis and ASB, were kidney 0. Any serious adverse consequences of ASB in nonrenal transplant recipients would be even more uncommon than symptomatic UTIs and are, therefore, almost certainly negligible.

Even with the most optimistic assumptions about antimicrobial efficacy, screening and treatment of ASB in nonrenal SOT recipients would impart only negligible benefits high-quality evidence. Thus, it is reasonable to make a recommendation for SOT patients other than kidney transplant, which is no stronger than that for kidney transplant patients.

However, 1 study [] reported that 2 neutropenic patients with P. This suggests ASB may be a source for bacteremia in some neutropenic patients. Current management for patients with high-risk neutropenia typically includes prophylactic antimicrobial therapy, which also usually resolves bacteriuria, when present []. These patients are also monitored closely, and broad-spectrum antimicrobial therapy is initiated promptly when a febrile episode occurs.

With current management strategies for high-risk neutropenic patients, the urinary tract is an infrequent source for bacteremia. While no studies specifically address this question, screening for bacteriuria with specific antimicrobial treatment, if present, seems unlikely to provide important additional benefits when current standard of care for these patients is followed.

These studies should include patients with neutropenia attributable to causes other than chemotherapy, and patients with indwelling bladder catheters. Treatment of ASB in studies enrolling primarily males with SCI and without indwelling catheters is usually followed by early recurrence of bacteriuria after antimicrobial therapy, and reinfecting strains are more likely to be resistant to antimicrobials [].

Studies which evaluated antimicrobial treatment or prophylaxis, compared with placebo or no treatment, enrolled patients managed with intermittent catheterization and observed no differences in rates of symptomatic UTI between treatment groups [, ]. The evidence is limited by the small numbers of patients enrolled, and relatively short durations of follow-up.

Guidelines of the European Association of Urology for urological infections also conclude that screening for and treatment of ASB in patients with SCI are not recommended []. The inoculation of a nonpathogenic E.

The inoculation of this E. Two RCTs in a small number of patients with neurogenic bladders 20 and 27 patients, respectively reported that this approach protected against symptomatic UTI [, ].

However, the small numbers of subjects, methodological limitations, and limited current feasibility of establishing and maintaining bacteriuria means the role of bacterial interference to prevent symptomatic UTI in the SCI population remains undefined.

These studies do, however, support the concept of a protective effect of ASB and the conclusion that nontreatment of spontaneously developed long-term E. Patients with neurogenic bladder, such as those with SCI, are often bacteriuric and have genitourinary symptoms that might be compatible with symptomatic UTI, posing a diagnostic problem for clinicians.

In contrast to patients with normal sensation, many patients with SCI and symptomatic UTI do not present with classic symptoms of UTI, such as dysuria, and may have symptoms not considered consistent with a presentation for UTI in other populations. This difficulty in ascertainment of the symptoms in a bacteriuric SCI patient is the likely reason for treatment of many patients with ASB [].

There is also high-quality evidence that antimicrobials cause harm through adverse effects and costs, as well as increasing the risk for antimicrobial-resistant infections in the individual and the community.

ASB is associated with variable degrees of pyuria, so the validity of conventional urinalysis with dipstick is uncertain to interpret in SCI patients. Some studies have shown promising early results using urinary concentrations of the acute phase reactant IL-6, but more evidence is needed before this or other biomarkers can be routinely adopted in clinical settings [].

Further studies in SCI patients managed with intermittent or indwelling catheterization are needed to evaluate the significance of nonspecific symptoms, including incontinence and cloudy and malodorous urine, and the outcomes with early or delayed antimicrobial therapy. The universal formation of biofilm along the indwelling catheter means all patients ultimately develop bacteriuria if an indwelling catheter remains in situ.

Once bacteriuria is established in a catheterized urinary tract, antimicrobials can temporarily suppress the bacteriuria, but recurrence with the same or different species, often with organisms of increased antimicrobial resistance, occurs universally. For patients who develop bacteriuria, symptomatic UTI is infrequent.

Tambyah et al [] reported that of Only 15 of the 7. Only 1 episode of bacteremia was considered probably attributable to bacteriuria in newly catheterized patients. A retrospective cohort study of episodes of catheter-associated bacteriuria in patients reported Biofilms and catheter-associated urinary tract infections. Sobel JD, Kaye D. Urinary tract infections. Philadelphia, Pa. A prospective study of asymptomatic bacteriuria in sexually active young women. N Engl J Med. Kincaid-Smith P, Bullen M.

Bacteriuria in pregnancy. Smaill F. Antibiotics for asymptomatic bacteriuria in pregnancy. Cochrane Database Syst Rev. Prevention of preterm delivery and low birth weight associated with asymptomatic bacteriuria.

Obstet Gynecol. Short-term versus continuous antimicrobial therapy for asymptomatic bacteriuria in pregnancy. Duration of treatment for asymptomatic bacteriuria during pregnancy. A study of various tests to detect asymptomatic urinary tract infections in an obstetric population. Frequency and risk of acquisition. Am J Epidemiol. Screening for asymptomatic bacteriuria in pregnancy.

A decision and cost analysis. J Fam Pract. Consequences of asymptomatic bacteriuria in women with diabetes mellitus. Arch Intern Med. The clinical course of untreated asymptomatic bacteriuria in diabetic patients—year follow-up. Mater Med Pol. Antimicrobial treatment in diabetic women with asymptomatic bacteriuria.

Bacteriuria in a population sample of women: year follow-up study. Results from the prospective population-based study of women in Gothenburg, Sweden. Scand J Urol Nephrol. Bacteriuria and subsequent mortality in women. Therapy vs no therapy for bacteriuria in elderly ambulatory non-hospitalized women.

Prospective randomized comparison of therapy and no therapy for asymptomatic bacteriuria in institutionalized elderly women. Am J Med. Does asymptomatic bacteriuria predict mortality and does antimicrobial treatment reduce mortality in elderly ambulatory women [Published correction appears in Ann Intern Med ;]?. Ann Intern Med. Does eradicating bacteriuria affect the severity of chronic urinary incontinence in nursing home residents?.

Bacteriuria during follow-up in patients with spinal cord injury: I. Rates of bacteriuria in various bladder-emptying methods. Eradication of urinary tract infection following spinal cord injury. Urinary infection and complications during clean intermittent catheterization following spinal cord injury. J Urol. Cephalexin for susceptible bacteriuria in afebrile, long-term catheterized patients. Low risk of bacteremia during catheter replacement in patients with long-term urinary catheters.

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