Diagnosis Of Asymptomatic Bacteriuria Research Articles

Diagnosis of asymptomatic bacteriuria in pregnant women: Rational approaches

Asymptomatic bacteriuria (AB) during pregnancy has a negative impact on its course and also affects obstetric and perinatal outcomes. Objective. To optimize the diagnosis of AB in pregnant women to prevent possible negative effects of asymptomatic infections on obstetric and perinatal outcomes. Subjects and methods. A single-center prospective trial included 101 pregnant women, who in the first trimester had AB in different titers being detected by a screening bacteriological examination of their urine specimen. All the patients underwent repeated urinary bacteriological examination in compliance with all the requirements for this examination. The specific features of the course of pregnancy and perinatal outcomes were analyzed in women with bacteriuria detected in various titers. A control group consisted of 50 women without a history of urinary tract infections. Results. The repeated examination confirmed that 9 (9.0%) patients had bacteriuria in a titer ≥105 CFU/ml; 65 (70.6%) had this condition in a titer of 102–104 CFU/ml; no growth of etiologically significant microorganisms was found in 27 (29.4%) examinees. Studying the results of primary urine cultures revealed monoinfection in 72.3% of cases; a combination of two microorganisms was noted in 27.7%. The regional structure of the repeatedly isolated uropathogens is mainly represented by Enterobacteriales. The bacteriological examination of urine before antibacterial therapy repeatedly confirmed AB in a significant titer only in 9 patients (95% confidence interval, 0.042-0.162; p=0.029). Bacteriuria even through single separation of an uropathogen in a low titer during pregnancy is associated with an increased risk for mild anemia and hypertension. Conclusion. Even the single detection of uropathogens in the urine of pregnant women, including those with a low diagnostic titer of 102–104 CFU/ml is associated with the unfavorable course of pregnancy.

Etiology, frequency and clinical outcomes related to Urinary Tract Infection and Asymptomatic Bacteriuria in pregnant women in a municipality of Southeast Brazil

Objective: The aim of this study was to investigate cases of Urinary tract infection (UTI) and Asymptomatic bacteriuria (ASB) in pregnant women in a Brazilian city, as well as identify the pathogens causing these diseases and its antimicrobial susceptibility profile. Also, we investigated the antibiotic therapy used in pregnant women to treat UTI and ASB, and the comorbidities which can be related to increased risk of these type of infection. Methods: This study was prospective research, descriptive and exploratory, with a qualitative approach, conducted among 35 pregnant women from October 2019 at Basic Health Unit (BHU) in Diadema, São Paulo, Brazil. Patient’s data were obtained using specific terms in the search filters from data base of BHU, as well the results of identification of bacterial species isolated from urine culture and the Antimicrobial Susceptibility Testing (AST). Results: From 35 study participants, 34.3% had a presumptive diagnosis of ASB and 65.7% had a diagnosis of symptomatic UTI. The predominant bacteria isolated were Escherichia coli (n=11) and Staphylococcus saprophyticus (n=2). The AST revealed a low rate of resistance to antimicrobials used for the treatment of UTI. The antimicrobial agents most prescribed was cephalexin. Further, 13 pregnant women presented comorbidities. Also, 20% presented premature delivery and 11,4% babies presented neonatal diseases. Conclusion: In this study, it was possible to know which bacterial species are commonly isolated from pregnant women urine cultures and evaluate the isolates susceptibility profile, as well as analyze the common antimicrobial therapy prescribed to these women.

Clinical outcomes associated with guideline-discordant management of asymptomatic bacteriuria and urinary tract infection in hospitalized patients with neurogenic bladder.

To compare clinical outcomes associated with appropriate and inappropriate management of asymptomatic bacteriuria (ASB) and urinary tract infection (UTI) among inpatients with neurogenic bladder (NB). Multicenter, retrospective cohort. The study was conducted across 4 Veterans' Affairs hospitals. The study included veterans with NB due to spinal cord injury or disorder (SCI/D), multiple sclerosis (MS), or Parkinson's disease (PD) hospitalized between January 1, 2017, and December 31, 2018, with diagnosis of ASB or UTI. In a medical record review, we classified ASB and UTI diagnoses and treatments as appropriate or inappropriate based on national guidelines. Frequencies of Clostridioides difficile infection, acute kidney injury, 90-day hospital readmission, postculture length-of-stay (LOS), and multidrug-resistant organisms in subsequent urine cultures were compared between those who received appropriate and inappropriate management. We included 170 encounters with ASB (30%) or UTI (70%) diagnoses occurring for 166 patients. Overall, 86.1% patients were male, 47.6% had SCI/D and 77.6% used bladder catheters. All ASB encounters had appropriate diagnoses, and 96.1% had appropriate treatment. In contrast, 37 UTI encounters (31.1%) had inappropriate diagnoses and 61 (51.3%) had inappropriate treatment, including 30 encounters with true ASB. Among patients with SCI/D or MS, appropriate ASB or UTI diagnosis was associated with a longer postculture LOS (median, 14 vs 7.5 days; P = .02). We did not detect any significant associations between appropriate versus inappropriate diagnosis and treatment and other outcomes. Almost one-third of UTI diagnoses and half of treatments in hospitalized patients with NB are inappropriate. Opportunities exist to improve ASB and UTI management in patients with NB to minimize inappropriate antibiotic use.

Evaluating a Hospitalist-Based Intervention to Decrease Unnecessary Antimicrobial Use in Patients With Asymptomatic Bacteriuria.

OBJECTIVE Inappropriate treatment of asymptomatic bacteriuria (ASB) in the hospital setting is common. We sought to evaluate the treatment rate of ASB at the 3 hospitals and assess the impact of a hospitalist-focused improvement intervention. DESIGN Prospective, interventional trial. SETTING Two community hospitals and a tertiary-care academic center. PATIENTS Adult patients with a positive urine culture admitted to hospitalist services were included in this study. Exclusions included pregnancy, intensive care unit admission, history of a major urinary procedure, and actively being treated for a urinary tract infection (UTI) at the time of admission or >48 hours prior to urine collection. INTERVENTIONS An educational intervention using a pocket card was implemented at all sites followed by a pharmacist-based intervention at the academic center. Medical records of the first 50 eligible patients at each site were reviewed at baseline and after each intervention for signs and symptoms of UTI, microbiological results, antimicrobials used, and duration of treatment for positive urine cultures. Diagnosis of ASB was determined through adjudication by 2 hospitalists and 2 infectious diseases physicians. RESULTS Treatment rates of ASB decreased (23.5%; P=.001) after the educational intervention. Reductions in treatment rates for ASB differed by site and were greatest in patients without classic signs and symptoms of UTI (34.1%; P<.001) or urinary catheters (31.2%; P<.001). The pharmacist-based intervention was most effective at reducing ASB treatment rates in catheterized patients. CONCLUSIONS A hospitalist-focused educational intervention significantly reduced ASB treatment rates. The impact varied across sites and by patient characteristics, suggesting that a tailored approach may be useful. Infect Control Hosp Epidemiol 2016;37:1044-1051.

Detection of Urinary Tract Infection (UTI) and Asymptomatic Bacteriuria using Urinalysis Parameters, a Review

Background:Urinary tract infections (UTIs) are a very common occurrence globally. In order to diagnose a UTI accurately, one must be aware of the variable presentations of a UTI. Given this, UTIs generally have three presentations: Asymptomatic bacteriuria (ASB), acute cystitis, and pyelonephritis. Due to the pathology of UTIs, it is not uncommon to see significant bacteriuria in asymptomatic patients. Since UTIs are common, readily available means of diagnosis which are accurate and cost effective are needed. Therefore, urinalysis is regularly used in the diagnosis of UTI and ASB in pregnancy because they are easy to perform and produce results rapidly. However, there appears to be little evidence of their accuracy and cost-effectiveness as compared with standard culture techniques when quantified for positive and negative likelihood ratios. This is a literature review of the efficacy of urinalysis screening in the diagnosis of asymptomatic bacteriuria or UTI in pregnancy. Objective: The sensitivity and accuracy of urinanalysis parameters in detecting UTIs and Asymptomatic Bacteriuria during pregnancy was reviewed. This was done in order to evaluate the accuracy of nitrite and Leucocyte Esterase (LE) dipsticks for screening and treating UTIs and ASB in situations where culture results were not available. Conclusion: Overall, this review demonstrates that the urine dipstick test alone seems to be useful in to exclude the presence of an infection if the results of both nitrites and leukocyte-esterase are negative. Different studies reported broad ranges of sensitivities and specificities for urinalysis parameters. Combination of nitrite and leukocyte esterase when both parameters are positive, seem to have the highest specificity in detecting bacteriuria in asymptomatic pregnant women. Although the combination of positive test results are very sensitive in practice, the usefulness of the dipstick test alone to rule in an infection still remains doubtful, even with high pre-test probabilities. Urine culture remains the gold standard for diagnosis of urinary tract infection and asymptomatic bacteruria.

Asymptomatic bacteriuria is an independent predictor of urinary tract infections in an ambulatory cirrhotic population: a prospective evaluation

Asymptomatic bacteriuria (ASB) is a risk factor for urinary tract infections (UTIs) in many patients without liver disease. It remains unclear whether a diagnosis of ASB in an outpatient with cirrhosis could be utilized to predict the subsequent development of a UTI. We undertook this study to determine the prevalence and incidence of ASB in an outpatient population and its association with UTI. We prospectively evaluated 108 adult outpatients with cirrhosis over a 6-month period. Monthly midstream urines (MSU) were performed to detect the occurrence of UTI and ASB (culture of ≥10(8) CFU/L of a urinary pathogen in the absence of UTI symptoms). Of 108 patients enrolled, 99 completed at least one MSU, for a total of 489 MSUs. Total follow-up was 44 person-years. The incidences of ASB and UTI were 181 and 250 per 1000 person-years, respectively. The prevalences of ASB and UTI on the first MSU were 5 and 1%, respectively. In total, 8% of patients developed an episode of ASB and 11% developed a UTI during the study period. Univariate predictors of UTI were female gender, primary biliary cirrhosis, number of previous UTIs and preceding ASB. Preceding ASB was the only independent predictor of UTI on multivariate analysis, with an odds ratio of 6.2 (1.1-34.3), P=0.04. Cirrhotic patients have higher rates of ASB and UTI than reported in the general population. ASB is an independent predictor of UTI. Further studies are necessary to determine whether routine screening and antimicrobial treatment of ASB is warranted.

Outcome of Pregnancy Complicated by Asymptomatic Bacteriuria

Objective: To evaluate pregnancy outcome in women with asymptomatic bacteriuria (ASB). Design: Prospective cohort study. Setting: The University Teaching Hospital Yaounde (Cameroon) from May 1st, 2012 to April 30th, 2014. Population: Fifty two women with (treated) ASB and 156 without ASB were followed up till delivery. Methods: Data were analyzed using Epi-info 3.5.4. Data of women with ASB were compared to those of women without ASB. Fisher's exact test and t-test were used for comparison. P<0.05 was considered statistically significant. Main outcome measures: Maternal age and parity, bacteria isolated from urine culture and its sensitivity, gestational age (GA) at diagnosis of ASB and at delivery, maternal complication during pregnancy, fetal sex and the birth weight. Results: The mean GA at diagnosis of ASB was 21.0 ± 7.0 weeks. The main micro-organism isolated was Escherichia coli. The two antibiotics usually efficient were ceftriaxone and amoxicillin-clavulanic acid. There was no significant differences regarding maternal age, parity or the mean GA at delivery in both groups. ASB was associated with preterm birth (RR 2.4) and especially with low birth weight (LBW:<2500 g) (RR 5), especially when diagnosed early in pregnancy (RR 7.4). No case of pre eclampsia or pyelonephritis was observed in the ASB group. Conclusion: ASB is associated with LBW especially when present early in pregnancy.

Diagnosis of asymptomatic bacteriuria and associated risk factors among pregnant women in mangalore, karnataka, India.

Asymptomatic bacteriuria (AB) is common inwomen and increases in prevalence with age or sexual activity. Prompt detection and treatment of this condition and associated factors decreases complications like acute pyleonephritis, intrauterine growth retardation and preterm labour. Chromogenic media is a versatile tool in rapid primary screening of the causative organisms considerably reducing daily routine workload. To determine the prevalence of AB among pregnant women in a tertiary care set-up and analyse the contributory risk factors, its effects on pregnancy and the role of chromogenic media in the laboratory diagnosis of these cases. Urine samples of all pregnant women attending pre-natal check-ups with no genitourinary complaints, history of fever or antibiotic intake were collected for Gram stain, culture and antibiotic sensitivity tests. A second urine specimen for culture and sensitivity testing was obtained from those with significant bacteriuria. The results were compared with patients showing negative urine cultures. The overall prevalence of this clinical condition in our study was 13.2%. The significant isolates were Klebsiella pneumonia and E.coli and the most common risk factor was a previous history of urinary tract infection. The isolates were easily identified by using chromogenic agar ( HiCrome ) but colonies of uncommon pathogens like Acinetobacter and Streptococcus species appeared white and needed further identification. Screening of pregnant women for AB at first prenatal checkup helps analyse the associated factors and prevents its effects on pregnancy. The use of a chromogenic media can enhance reporting accuracy and will be an effective tool to monitor these cases routinely.

Editorial Commentary: Asymptomatic Bacteriuria--Shift of Paradigm

Initial studies on quantitative urine cultures obtained from large numbers of patients have established so-called significant (true) bacteriuria at a threshold of ≥10 colony-forming units per milliliter [1]. Because asymptomatic bacteriuria (ABU) has been found with particular frequency in populations more likely to develop pyelonephritis (ie, individuals with diabetes mellitus, pregnancy, obstructive uropathy, past history of instrumentation of the urinary tract), a strong relationship between bacteriuria and pyelonephritis was assumed. This was consolidated by the observation that in pregnancy elimination of ABU decreases the risk for a symptomatic infection [2]. Although bacteriuria is present in a relatively asymptomatic population, it is virtually always necessary for the development of symptomatic disease. Therefore, it was assumed that the presence of bacteriuria defines a population at risk and the elimination of bacteriuria minimizes the risk for a clinically symptomatic disease [2]. The discrepancy between the frequency of pyelonephritis found in autopsies and that diagnosed during life in only about one-fifth of the cases was explained by a high incidence of clinically atypical or inapparent infections [3]. At that time bacteriuriawas considered dangerous in any case, because bacteriuria detected at a significant quantity, even if asymptomatic, was associated with a substantially increased risk of pyelonephritis and premature delivery. Subsequently well-performed, randomized clinical studies in adult women, schoolgirls, long-term care facility residents, spinal cord–injured patients, and diabetic women, however, have consistently documented that the treatment of bacteriuria in asymptomatic patients does not provide any benefit for the patient [4, 5]. Therefore, the term “asymptomatic urinary tract infection” (UTI) was abandoned and redefined as ABU. The diagnosis of ABU is made independent of the presence of pyuria commonly found in patients with ABU [4]. Nowadays ABU is considered a stable bacterial colonization of the urinary tract, similar to commensalism at other mucosal sites [6]. Apart from clinical trials, ABU has been investigated through molecular methods [6]. ABU Escherichia coli isolates from outpatients or hospitalized patients after catheterization or other urological invasive procedures were compared with commensal E. coli isolates from the intestinal flora of healthy individuals [6]. The ABU isolates had a similar overall virulence gene repertoire, which sets them apart from many commensals. Typical uropathogenic E. coli (UPEC) virulence genes, however, were less frequently observed in hospital ABU strains than in outpatient ABU strains or commensals [6]. The diminished virulence from outpatient ABU isolates compared with that of ABU strains from hospitalized patients shows that loss of expression or decay of virulence genes facilitate longterm carriage and adaptation to host environments [6]. A prototype ABU strain, E. coli 83972, isolated from a schoolgirl with long-lasting ABU with this strain, has been completely sequenced in the meantime [7]. Comparing this ABU strain with UPEC strains, the ABU strain has a smaller genome than the UPEC strains with deletions or point mutations in several virulence genes, suggesting that ABU strains undergo a programmed reductive evolution within human hosts [6, 8]. In asymptomatic patients colonized in the lower urinary tract with this ABU strain, superinfection with other strains seems to be prevented even if left untreated [8–11]. This phenomenon, the socalled bacterial interference, is due to the fact that within our body’s bacterial habitats microbial interaction exists, in competing for nutrients and producing toxic molecules. Thus, a microbial balance is established on colonized surfaces, such as the skin and mucosal orifices. This socalled human microbiome is considered a potent defense mechanism against superinfecting pathogenic bacteria [8]. The idea of bacterial interference was further developed. The ABU E. coli Received 29 May 2012; accepted 31 May 2012; electronically published 7 June 2012. Correspondence: Kurt Naber, Karl-Bickleder-Str. 44c, D-94315 Straubing, Germany (kurt@nabers.de). Clinical Infectious Diseases 2012;55(6):778–80 © The Author 2012. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals. permissions@oup.com. DOI: 10.1093/cid/cis541

Infectious Diseases Society of America Guidelines for the Diagnosis and Treatment of Asymptomatic Bacteriuria in Adults

1. The diagnosis of asymptomatic bacteriuria should be based on results of culture of a urine specimen collected in a manner that minimizes contamination (A-II) (table 1). • For asymptomatic women, bacteriuria is defined as 2 consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts 10 cfu/mL (B-II). • A single, clean-catch voided urine specimen with 1 bacterial species isolated in a quantitative count 10 cfu/mL identifies bacteriuria in men (BIII). • A single catheterized urine specimen with 1 bacterial species isolated in a quantitative count 10 cfu/mL identifies bacteriuria in women or men (A-II). 2. Pyuria accompanying asymptomatic bacteriuria is not an indication for antimicrobial treatment (A-II). 3. Pregnant women should be screened for bacteriuria by urine culture at least once in early pregnancy, and they should be treated if the results are positive (A-I). • The duration of antimicrobial therapy should be

Is a second urine specimen necessary for the diagnosis of asymptomatic bacteriuria?

By use of pulse-field gel electrophoresis, we evaluated the molecular identity of 32 Escherichia coli isolates obtained in 2 consecutive urine cultures from 16 patients as part of a large study of asymptomatic bacteriuria in diabetic women and found different E. coli isolates in 7 of 16 patients, meaning that nearly half (44%) of the patients who had been previously classified as having asymptomatic bacteriuria were reinfected with a different strain.

The case against screening urinalyses for asymptomatic bacteriuria in children

• Screening children for asymptomatic bacteriuria to prevent pyelonephritis and renal scarring is widely recommended, but its cost-effectiveness has not been established. We reviewed published studies to determine the costs and benefits of screening toilet-trained, asymptomatic children for bacteriuria. Given the sensitivity and specificity of current screening methods (approximately 80% each) and the prevalence of bacteriuria in asymptomatic children (approximately 1% in girls and 0.03% in boys), screening 100 000 children would result in 19 897 (20%) false-positive tests; initial screening and two urine cultures to confirm the diagnosis of asymptomatic bacteriuria would miss 28% of 515 children with true bacteriuria, and cost nearly $2.9 million. There is no evidence that detection and treatment of children with asymptomatic bacteriuria prevents subsequent pyelonephritis or renal scarring. Screening for bacteriuria in asymptomatic children is costly, fails to prevent pyelonephritis or renal scarring, and should be discontinued as a part of routine well-child care. ( AJDC . 1992;146:343-346)

The treatment of asymptomatic bacteriuria in the elderly.

The treatment of asymptomatic bacteriuria in the elderly.