Difficile Infection Diagnosis Research Articles

Assessment of Knowledge and Practice of Healthcare Providers in Saudi Arabia Regarding Clostridioides difficile Infection Diagnosis and Management: A Cross-Sectional Questionnaire-Based Study.

Diagnosis of Clostridioides difficile infection (CDI) depends on clinical presentation and laboratory testing. Stool diagnostic tests are essential for effective detection of toxigenic C. difficile strains. No study to date has evaluated the readability of microbiology labs in Saudi Arabia to test for CDI and evaluated the knowledge and practice of healthcare providers regarding CDI management. Therefore, this study aimed to assess the knowledge and practice of healthcare providers in Saudi Arabia regarding CDI diagnosis and treatment. A cross-sectional, descriptive, questionnaire-based study was conducted on healthcare providers in Saudi Arabia, primarily physicians and clinical pharmacists. The questionnaire was developed based on a literature review and input from infectious diseases experts. The questionnaire was administered online. Data were analyzed using descriptive and inferential statistics. Of 183 respondents, 27.9% had adequate knowledge on CDI diagnosis and management. The majority were internal medicine specialists (37.7%) working in governmental or semi-governmental hospitals (80.9%) in central (46.6%) or southern (30.1%) regions of Saudi Arabia. Most participants assessed laxative use (86.3%) and reported positive C. difficile specimens to infection control (67.2%). However, knowledge varied, with 57.4% supporting unnecessary retesting and 53% assuming positive PCR test indicates moderate CDI probability. Factors such as specialization, hospital accreditation status, and bed capacity influenced knowledge levels (p<0.01 for all factors). The study revealed a significant knowledge gap among Saudi healthcare providers regarding CDI diagnosis, management, and severity classification, highlighting the need for improved education and adherence to guidelines to improve patient outcomes and reduce recurrence risks.

Improving care for patients with Clostridioides difficile infection: A clinical practice and healthcare systems perspective.

Arriving at a C. difficile infection (CDI) diagnosis, treating patients and dealing with recurrences is not straightforward, but a comprehensive and well-rounded understanding of what is needed to improve patient care is lacking. This manuscript addresses the paucity of multidisciplinary perspectives that consider clinical practice related and healthcare system-related challenges to optimizing care delivery. We draw on narrative review, consultations with clinical experts and patient representatives, and a survey of 95 clinical and microbiology experts from the UK, France, Italy, Australia and Canada, adding novel multi-method evidence to the knowledge base. We examine the patient pathway and variations in clinical practice and identify, synthesize insights on and discuss associated challenges. Examples of key challenges include the need to conduct multiple tests for a conclusive diagnosis, treatment side-effects, the cost of some antibiotics and barriers to access of fecal microbiota transplantation, difficulties in distinguishing recurrence from new infection, workforce capacity constraints to effective monitoring of patients on treatment and of recurrence, and ascertaining whether a patient has been cured. We also identify key opportunities and priorities for improving patient care that target both clinical practice and the wider healthcare system. While there is some variety across surveyed countries' healthcare systems, there is also strong agreement on some priorities. Key improvement actions seen as priorities by at least half of survey respondents in at least three of the five surveyed countries include: developing innovative products for both preventing (Canada, Australia, UK, Italy, and France) and treating (Canada, Australia, and Italy) recurrences; facilitating more multidisciplinary patient care (UK, Australia, and France); updating diagnosis and treatment guidelines (Australia, Canada, and UK); and educating and supporting professionals in primary care (Italy, UK, Canada, and Australia) and those in secondary care who are not CDI experts (Italy, Australia, and France) on identifying symptoms and managing patients. Finally, we discuss key evidence gaps for a future research agenda.

S196 Clostridioides difficile Infection (CDI) Increased in Individuals Diagnosed With Prior Colorectal Adenomas

Introduction: Clostridioides difficile infection (CDI) is increased in patients with colorectal cancer, but no one has investigated if CDI is also higher in individuals with prior history of colorectal adenomas seen on colonoscopy. Methods: We conducted a hospital-based cohort study composed of patients with diarrhea admitted to University of Michigan from 3/2016 to 12/2017 who were tested for C. difficile. Two hundred ninety-six diagnosed with C. difficile and 571 with non-C. difficile diarrhea were enrolled into the larger study. We abstracted prior colonoscopy reports and pathology reports from the medical records. Patients who had undergone colonoscopy were included in this analysis. Six hundred forty-seven underwent colonoscopy and 111 were diagnosed with colorectal adenomas prior to enrollment in the study. Logistic regression models were used to derive odds ratios (ORs) and 95% confidence intervals (95% CI) to evaluate comparisons between cases diagnosed with C. difficile and non-C. difficile diarrhea controls. We analyzed the association between history of colorectal adenoma diagnosis and CDI. (Figure, Table) Results: We found an increased risk of CDI in individuals with a prior colorectal adenoma (HR 1.64; 95% confidence interval (CI) 1.06-2.54) after adjusting for age, sex, obesity, complicated and uncomplicated diabetes and inflammatory bowel disease. Notably we also found a significant decreasing association between time since polypectomy and CDI with greater risk associated with greater time since colonoscopy. Conclusion: This study showed a higher incidence of CDI in individuals with a prior history of adenoma.Risk decreases over time since last polypectomy, which lends support to the hypothesis that there is a link between adenomas and subsequent CDI risk. Futures studies are needed to confirm this finding and elucidate mechanisms as this relationship could help target prophylactic measures in these individuals to avoid future infection.Figure 1.: Risk factors of CDI estimated with multivariate logistic regression. Model was adjusted for Complicated DM, Obesity, gender, history of adenoma, and age Table 1. - Baseline characteristics of subjects by Clostridioides difficile infection (CDI) diagnosis 1. Clostridioides difficile infection (CDI), Diabetes mellitus (DM) 2. Pearson's Chi-squared test; Fisher's exact test. 3. Interquartile range (IQR). 4. n (%) Characteristic Non-CDI1 Diarrhea (N=422) CDI1 Diarrhea (N=225) p-value2 Age 53 (39, 64)3 55 (45, 69)3 0.6 Non-Hispanic Caucasian 337 (80%)4 178 (79%)4 0.8 History of adenoma 58 (14%)4 53 (24%)4 0.002 Gender 0.11 Female 249 (59%)4 118 (52%)4 Male 73 (41%)4 107 (48%)4 Obesity 43 (10%)4 34 (15%)4 0.07 IBD 155 (37%)4 57 (25%)4 0.003 Complicated DM1 42 (10.0%)4 48 (21%)4 < 0.001

54. The Effect of Targeting High-Risk Patients for Antimicrobial Stewardship Intervention on Hospital-Onset Clostridioides Difficile Infection Rates

Background Clostridioides difficile infection contributes to significant burden on patients and the healthcare system, costing billions in excess costs every year for hospital care. Continued use of antibiotics after C. difficile infection diagnosis is a risk factor for recurrent infection. Also, individuals who have had a recurrence of C. difficile infection are at a higher risk of subsequent episodes. MethodsThis prospective, observational, pre-post study evaluated the effect of implementing a targeted antimicrobial stewardship initiative towards a high-risk target population on the rate of in-hospital C. difficile infection rates. High-risk targets were identified through an electronic health system report of admitted patients at a large academic medical center who were toxin assay positive or had a documented history of C. difficile infection. Subjects who met the criteria were assessed for interventions by the pharmacy-driven antimicrobial stewardship service. The primary outcome compared the hospital-onset C. difficile rates and standardized infection ratio (SIR) before and after implementation of the initiative. The SIR is reported to the National Healthcare Safety Network (NHSN) and is calculated as a ratio between the number of observed and predicted infections, which is adjusted for facility-specific factors that contribute C. difficile risk. Negative binomial regression was used to calculate the predicted C. difficile infections in the SIR. Poisson regression was used to generate a 95% prediction interval for the predicted C. difficile infection rate. ResultsThe mean age of subjects was 63 years old and 85% had no history of prior C. difficile infection. The most common intervention was de-escalation of antibiotics (46%). The post-implementation SIR was 0.55 and hospital-onset C. difficile rate was 13, both of which were significantly lower than predicted. ConclusionTargeting patients who have a history of or are newly diagnosed with C. difficile infection may decrease hospital-onset C. difficile rates.Disclosures All Authors: No reported disclosures

Pragmatic Strategy for Fecal Specimen Storage and the Corresponding Test Methods for Clostridioides difficile Diagnosis.

The quality of fecal specimens is one of the factors responsible for successful Clostridioides difficile infection (CDI) diagnosis. The quality depends largely on the storage conditions, including the temperature and time period. In this study, we organized the outputs of previous studies, filled experimental gaps in the knowledge of storage conditions, and introduced a pragmatic strategy for fecal storage for CDI diagnosis. A 5-step pathway was adopted to develop the fecal specimen storage strategy as follows: step 1, bibliomic analysis; step 2, experimental gap-filling; step 3, comparative evaluation; step 4, strategy development; step 5, internal review. Step 1 identified eight articles providing experimental information on the effects of fecal specimen storage conditions on the effectiveness of C. difficile detection methods. Step 2 provided additional quantitative data on C. difficile vegetative and spore cell viability and DNA stability. All previous and current results were compared (step 3). In step 4, fir general and nine special strategies were developed, followed by an internal review of the overall approaches (step 5). It is recommended to separate fecal samples into aliquots before testing and storing them. It is particularly recommended that fecal specimen samples be stored for CDI diagnosis at 4 °C for up to 60 days for all test methods.

Recent advances in Clostridioides difficile infection epidemiology, diagnosis and treatment in children.

The US Centers for Disease Control and Prevention (CDC) classified Clostridioides difficile as an 'urgent' public health threat that requires 'urgent and aggressive action'. This call to action has led to new discoveries that have advanced C. difficile infection (CDI) epidemiology, diagnosis and treatment, albeit predominantly in adults. In 2017, the Infectious Diseases Society of America and Society for Healthcare Epidemiology of America published clinical practice guidelines for both adults and children. At that time, recommendations in children were generally limited to relatively low-quality evidence. Since publication of this guidance, there have been many advancements in the understanding of CDI in children. These include better understanding of healthcare settings as uncommon sources of C. difficile acquisition in children; risk factors for recurrent and community-associated CDI; performance of diagnostic tests in children and strategies for optimizing their use; and a more rigorous evidence base for CDI treatment in children, including the first-ever randomized controlled trial of CDI treatment in children and the largest study of fecal microbiota transplantation in children. This review highlights the most recent salient advancements in paediatric CDI knowledge and practice that supplement published clinical guidance provided prior to these advancements.

Rate and consequences of missed Clostridioides (Clostridium) difficile infection diagnosis from nonreporting of Clostridioides difficile results of the multiplex GI PCR panel: experience from two-hospitals

IntroductionIt is common among microbiology laboratories to blind the Clostridioides difficile (C. difficile) BioFire FilmArray GI Panel result in fear of overdiagnosis. MethodsWe examined the rate of missed community-onset C. difficile infection (CDI) diagnosis and associated outcomes. Adult patients with FilmArray GI Panel positive for C. difficile on hospital admission who lacked dedicated C. difficile testing were included. ResultsAmong 144 adults with a FilmArray Panel positive for C. difficile, 18 did not have concurrent dedicated C. difficile testing. Eight patients were categorized as possible, 5 as probable and 4 as definite cases of missed CDI diagnosis. We observed associated delays in initiation of appropriate therapy, intensive care unit admissions, hospital readmissions, colorectal surgery and death/discharge to hospice. Five out of 17 lacked risk factors for CDI. ConclusionThe practice of concealing C. difficile FilmArray GI Panel results needs to be reconsidered in patients presenting with community-onset colitis.

Critical Care Management of the Patient with Clostridioides difficile.

To review published clinical evidence on management of Clostridioides difficile infection in critically ill patients. We obtained relevant studies from a PubMed literature review and bibliographies of reviewed articles. We selected English-language studies addressing aspects of C. difficile infection relevant to critical care clinicians including epidemiology, risk factors, diagnosis, treatment, and prevention, with a focus on high-quality clinical evidence. We reviewed potentially relevant studies and abstracted information on study design, methods, patient selection, and results of relevant studies. This is a synthetic (i.e., not systematic) review. C. difficile infection is the most common healthcare-associated infection in the United States. Antibiotics are the most significant C. difficile infection risk factor, and among antibiotics, cephalosporins, clindamycin, carbapenems, fluoroquinolones, and piperacillin-tazobactam confer the highest risk. Age, diabetes mellitus, inflammatory bowel disease, and end-stage renal disease are risk factors for C. difficile infection development and mortality. C. difficile infection diagnosis is based on testing appropriately selected patients with diarrhea or on clinical suspicion for patients with ileus. Patients with fulminant disease (C. difficile infection with hypotension, shock, ileus, or megacolon) should be treated with oral vancomycin and IV metronidazole, as well as rectal vancomycin in case of ileus. Patients who do not respond to initial therapy should be considered for fecal microbiota transplant or surgery. Proper infection prevention practices decrease C. difficile infection risk. Strong clinical evidence supports limiting antibiotics when possible to decrease C. difficile infection risk. For patients with fulminant C. difficile infection, oral vancomycin reduces mortality, and adjunctive therapies (including IV metronidazole) and interventions (including fecal microbiota transplant) may benefit select patients. Several important questions remain regarding fulminant C. difficile infection management, including which patients benefit from fecal microbiota transplant or surgery.

South African Society of Clinical Microbiology Clostridioides difficile infection diagnosis, management and infection prevention and control guideline.

Clostridioides difficile infection (CDI) is a problem in both developed and developing countries and is a common hospital-acquired infection. This guideline provides evidence-based practical recommendations for South Africa and other developing countries. The scope of the guideline includes CDI diagnostic approaches; adult, paediatric and special populations treatment options; and surveillance and infection prevention and control recommendations.

S0224 Decreasing the Delays in Clostridioides difficile Infection Diagnosis - A Quality Improvement Initiative

INTRODUCTION: Clostridium difficile is the most common cause of healthcare-associated diarrhea in developed countries. Despite the current rapid C. difficile infection (CDI) testing methods, studies have shown that delays in CDI diagnosis still exist due to various factors. Identification and intervention of modifiable factors contributing to delays could possibly lead to early initiation of appropriate infection control measures and treatment. Our objective is to identify the factors causing the delays at various levels from the time of CDI test order to results. METHODS: We conducted a 6-month retrospective study followed by a 3-month prospective interventional study at Mercy Philadelphia Hospital. Chart review was performed to evaluate the time from CDI test orders to stool specimens collection. Interviews were conducted on CDI patients and a subset of nurses and physicians to identify the reasons for delays in diagnosis. A 3-month intervention was performed to address the delays. This included an Electronic medical record (EMR) alert to notify infection control staff and educating nurses and physicians focusing on the importance of timely CDI testing for initiation of treatment. RESULTS: CDI test orders on 140 patients with 80 in the pre- and 60 post-intervention periods were reviewed. No significant difference in patient characteristics and demographics was noted between the 2 groups. The mean time from the test order to test result was significantly lower after the intervention period compared to the pre-intervention period 2 hours vs. 19 hours (P < 0.0001). CONCLUSION: Factors affecting the time from test order to specimen collection accounted for most of the delays. Education of the health care workers at all levels on prompt isolation of suspected CDI patients and the importance of expedited testing significantly reduced the delays in diagnosis. This may reduce the overuse of empirical CDI therapy, reduce delays in initiation of appropriate therapy and finally, decrease C. difficile transmission with timely isolation.

Analysis of Routine and Integrative Data from Clostridioides difficile Infection Diagnosis and the Consequent Observations

Background:Clostridioides difficileInfection (CDI) is an acute disease that needs a fast proper treatment. Unfortunately, the diagnosis, and above all the understanding of the results, remain arduous.Objective:This study analyzed routine and integrative results of all fecal samples from patients over time. Our aim was to understand the dynamics of CDI infection and the meaning of “difficult to interpret” results, to make physicians better understand the various tools they can use.Methods:We evaluated routine results obtained from 815 diarrheal stools with Enzyme Immunoassay (EIA) that detectsC. difficileGlutamate Dehydrogenase (GDH) antigen and toxin B. We also reanalyzed a part of samples using integrative tests: a Real-time polymerase chain reaction (RT-PCR) forC. difficiletoxin B gene (tcdB) and the automated immunoassay VIDASC. difficilesystem for GDH and toxins A/B.Results:EIA GDH positivity increased through multiple testing over time, with aPvalue &lt;0.001, depicting a sort of bacterial growth curve. Eighty-five percent of GDH positive/toxin B negative,i.e., discrepant, samples PCR weretcdBpositive, 61.5% of discrepanttcdBpositive samples were VIDAS toxins A/B positive, and 44.4% of GDH EIA negative stools were VIDAS GDH positive.Conclusion:The results confirmed the low sensitivity of the EIA system forC. difficileGDH and toxins, questioned the use of the latter for concluding any CDI diagnostic algorithm, and led us to indicate the algorithm beginning with tcdB molecular research, and continuing in positive cases with VIDAS CD GDH method, as the most effective for CDI.

2351. Rate and Consequences of Missed Clostridioides (Clostridium) difficile Infection Diagnosis from Non-disclosure of Clostridioides difficile Multiplex PCR Results. Two-Hospital Experience

BackgroundIt is common practice among microbiology laboratories in the United States to blind the BioFire FilmArray GI Panel results for Clostridioides (Clostridium) difficile (C. difficile) in fear of over-diagnosis of C. difficile infection (CDI).MethodsWe conducted a retrospective cohort study in 2 tertiary academic centers in New York to examine the rate of missed CDI diagnosis and the associated adverse outcomes from blinding the BioFire FilmArray GI Panel results for C. difficile. Of note, in one of the two included hospitals the list of daily positives is reviewed by an Infectious Diseases attending to determine whether cases have been tested for CDI and if not if they meet criteria for CDI. Adult patients with FilmArray GI Panel positive for C. difficile on admission to the hospital who lacked dedicated testing for C. difficile were included in the analysis and were stratified as possible, probable and definite cases of missed CDI diagnosis.ResultsAmong the 144 adult patients with a FilmArray GI Panel test positive for C. difficile within 48 hours of hospital admission, 18 did not have a concurrent dedicated C. difficile testing. Eight patients were categorized as possible cases of missed CDI diagnosis, 5 as probable and 4 as definite, for a total of 17 cases of at least possibly missed CDI diagnosis. One case was considered to represent C. difficile colonization rather than infection for a rate of 6.9% of CDI over-diagnosis based on the FilmArray GI Panel results. Missed CDI diagnoses were associated with a delay in initiation of appropriate therapy, admission to the intensive care unit, hospital re-admission, colorectal surgery and death/discharge to hospice. Five out of 17 cases of missed CDI diagnosis (29.4%) lacked traditional risk factors for CDI.ConclusionIn conclusion, the practice of concealing FilmArray GI Panel results for C. difficile may lead to a higher rate of missed CDI diagnosis than over-diagnosis and might need to be re-considered at least in patients with community-onset colitis of unknown etiology on presentation to the hospital.Disclosures All authors: No reported disclosures.

2360. Impact of a Two-Step Antimicrobial Stewardship Intervention on C. difficile Infection Diagnosis at an Urban Veteran’s Affairs Medical Center

Background C. difficile infection (CDI) is a common healthcare-associated infection and quality measure for hospitals. Diagnosis of CDI is challenging as testing modalities, i.e., nucleic acid amplification test (NAAT), are highly sensitive but cannot differentiate between colonization and infection. Therefore, judicious use of testing is critical to avoid unnecessary diagnosis and treatments.MethodsThis single-center, retrospective chart review evaluated the impact of a two-step diagnostic stewardship intervention on C. difficile diagnosis and use of oral vancomycin in the inpatient setting. For the first step of the intervention, providers were educated on appropriate diagnosis and treatment, and given access to an optional electronic CDI clinical decision support system (CDSS). For the second step of the intervention, the CDI NAAT stand-alone testing option was removed from the lab ordering menu and providers were required to use the CDSS to order testing. Clinical data including bed-days of care (BDOC), total number tests ordered, number of positive tests and use of oral vancomycin was collected for the pre-intervention period (1/1/16 – 3/31/17), post intervention period 1 (April 1, 2017–October 31/18) and post-intervention period 2 (November 1, 2018–March 31, 2019).ResultsCompared with the pre-intervention group, there were no significant differences in the number of total CDI NAATs ordered, positive CDI NAATs or vancomycin DOT/10,000 BDOC in post-intervention group 1. There was a reduction in the number of total CDI NAATs ordered (341 vs. 42 [87.7%]) and the number of positive CDI NAATs (56 vs. 7 [87.5%]) in post-intervention group 2, respectively. When this data were normalized based on bed days of care (BDOC), there were still significant reductions in NAATs ordered and number of positive CDI NAATs (64 vs. 27 [57.8%]; 11 vs. 5, respectively, [54.5%]) and with vancomycin oral DOT/10,000 BDOC (72 vs. 7 [90.3%]) (Table 1).ConclusionProvider education and an optional CDSS did not significantly impact CDI NAAT ordering or use of oral vancomycin for CDI. However, implementation of a mandatory CDSS for CDI testing was shown to significantly decrease the number of tests ordered, the number of positive tests, and the use of oral vancomycin. Disclosures All authors: No reported disclosures.

Human fecal metabolomic profiling could inform Clostridioides difficile infection diagnosis and treatment.

Clostridioides difficile is a significant public health threat, and diagnosis of this infection is challenging due to a lack of sensitivity in current diagnostic testing. In this issue of the JCI, Robinson et al. use a logistic regression model based on the fecal metabolome that is able to distinguish between patients with non-C. difficile diarrhea and C. difficile infection, and to some degree, patients who are asymptomatically colonized with C. difficile. The authors construct a metabolic definition of human C. difficile infection, which could improve diagnostic accuracy and aid in the development of targeted therapeutics against this pathogen.

Advances in Diagnostic Testing that Impact Infection Prevention and Antimicrobial Stewardship Programs.

The primary purpose of this review is to provide a summary of new and emerging laboratory technologies and testing platforms that impact infection prevention and antimicrobial stewardship programs. This review also summarizes available data describing the clinical impact of implementing these new technologies. While there is ample evidence that rapid organism identification technologies for positive blood cultures can ameliorate antimicrobial utilization, an assay that also provides expedited antimicrobial susceptibility testing results is now available and its clinical impact is under investigation. For C. difficile infection diagnosis, data related to performance and impact of "ultrasensitive" toxin assays is emerging in the literature although their role in C. difficile infection diagnosis remains unclear. For hospital-acquired pneumonia, a variety of rapid, automated, multiplexed, "pneumonia" panels have become commercially available and may impact surveillance definitions for ventilator-associated events. Finally, recent FDA clearance of various biochemical and molecular carbapenemase detection tests will facilitate rapid characterization of carbapenem-resistant organisms. Innovations in infectious diseases diagnostics have been making swift strides, broadening diagnostic scope; increasing accuracy and sensitivity; and reducing turnaround time. Many of these innovations directly impact infection prevention and antimicrobial stewardship operations. Close collaboration between infection control, antimicrobial stewardship, and the microbiology laboratory is necessary to ensure that new tests improve patient outcomes.

Poor yield of Clostridium difficile testing algorithms using glutamate dehydrogenase antigen and C. difficile toxin enzyme immunoassays in a pediatric population with declining prevalence of clostridium difficile strain BI/NAP1/027

We compared the performance of algorithmic Clostridium difficile infection (CDI) diagnosis with four molecular tests in children. Stool samples in patients 1-18 years old were tested with an algorithm (C. Diff Quik Chek Complete (QCC) reflexed to illumigene C. difficile); AmpliVue C. difficile (ACD); Lyra Direct C. difficile (Lyra); BD MAX C diff (BDM); and Xpert C. difficile (XCD). The gold standard was positivity by two tests. Sensitivity, specificity, positive predictive value, and negative predictive value were 85%, 99%, 93%, 97% for the algorithm; 21%, 99%, 78%, 87% for QCC’s toxin component; 94%, 99%, 94%, 99% for ACD; 88%, 99%, 94%, 98% for Lyra; 94%, 100%, 100%, 99% for BDM, and 94%, 99%, 94% and 99% for XCD. 9.6% of samples were ribotype 027. Algorithms may detect CDI with lower sensitivity compared to molecular methods in children. This may be related to low prevalence of NAP-1/ribotype 027.

Nucleic Acid Amplification Test Quantitation as Predictor of Toxin Presence in Clostridium difficile Infection.

Multistep algorithmic testing in which a sensitive nucleic acid amplification test (NAAT) is followed by a specific toxin A and toxin B enzyme immunoassay (EIA) is among the most accurate methods for Clostridium difficile infection (CDI) diagnosis. The obvious shortcoming of this approach is that multiple tests must be performed to establish a CDI diagnosis, which may delay treatment. Therefore, we sought to determine whether a preliminary diagnosis could be made on the basis of the quantitative results of the first test in algorithmic testing, which provide a measure of organism burden. To do so, we retrospectively analyzed two large collections of samples (n = 2,669 and n = 1,718) that were submitted to the laboratories of two Dutch hospitals for CDI testing. Both hospitals apply a two-step testing algorithm in which a NAAT is followed by a toxin A/B EIA. Of all samples, 208 and 113 samples, respectively, tested positive by NAAT. Among these NAAT-positive samples, significantly lower mean quantification cycle (Cq ) values were found for patients whose stool eventually tested positive for toxin, compared with patients who tested negative for toxin (mean Cq values of 24.4 versus 30.4 and 26.8 versus 32.2; P < 0.001 for both cohorts). Receiver operating characteristic curve analysis was performed to investigate the ability of Cq values to predict toxin status and yielded areas under the curve of 0.826 and 0.854. Using the optimal Cq cutoff values, prediction of the eventual toxin A/B EIA results was accurate for 78.9% and 80.5% of samples, respectively. In conclusion, Cq values can serve as predictors of toxin status but, due to the suboptimal correlation between the two tests, additional toxin testing is still needed.

A qualitative study to identify reasons for Clostridium difficile testing in pediatric inpatients receiving laxatives or stool softeners.

To understand why clinicians send Clostridium difficile tests from hospitalized children receiving laxatives or stool softeners, we performed a mixed-methods study. We prospectively identified tested patients and surveyed their clinicians by e-mail. Reasons for testing included changes in stooling pattern on baseline bowel regimen, other changes in clinical status, and risk factors for C difficile infection. Education targeting discontinuing bowel medications before C difficile testing could improve the specificity of pediatric C difficile infection diagnosis.

PP019 Clostridium Difficile Infection Diagnosis: Hospital-based Health Technology Assessment

INTRODUCTION:Clostridium difficile infection is the leading cause of nosocomial diarrhea in developed countries and may progress to pseudomembranous colitis, sepsis and death. The risk factors are antibiotics use, advanced age and prolonged hospitalization. The diagnosis of Clostridium difficile infection is based on clinical history in combination with laboratory tests, which detect the Clostridium difficile presence or toxins. Clostridium difficile remains in spore form contaminating the environment and requiring measures to prevent hospital transmission. Tests with more accurate results to identify true carriers of Clostridium difficile allow the clinician to determine a safer treatment. This study evaluated accuracy and cost-effectiveness of the real-time polymerase chain reaction compared with the enzyme-linked immunosorbent assay from the perspective of a Brazilian public cardiology hospital.METHODS:A study diagram was constructed by type of test, linking the data of prevalence in hospital, accuracy and direct costs of tests. The costs were based on a hypothetical population comparing two strategies to identify the incremental expenditure between technologies. The analysis included comparisons for each test versus no test, and with each other. The prices were converted to the American currency taking into account the date of purchase of each product and respective price.RESULTS:For real-time polymerase chain reaction test versus no test, 214 patients would have tested to justify one empirical treatment suspension, at a cost of USD90,926.46. For enzyme-linked immunosorbent assay test, to prevent one unnecessary treatment, 375 patients would have to be tested at a cost of USD6,603.75. In the comparative analysis, only a single false-positive patient would have the treatment suspended after performing 375 real-time polymerase chain reaction tests at USD424.89 each one (USD159,333.75 in total). An incremental cost of USD152,730.00 may be necessary to benefit a single patient by discontinuing empirical treatment.CONCLUSIONS:The Real-time polymerase chain reaction test has restrictions as a test of choice for the diagnosis of Clostridium difficile infection, in services with low disease prevalence. It undergoes a significant change in its positive predictive value and does not offer a great impact in the clinical diagnosis.

Antibiotic Exposure After Clostridium difficile Infection (CDI) Diagnosis in Pediatric Oncology Patients

Antibiotic Exposure After Clostridium difficile Infection (CDI) Diagnosis in Pediatric Oncology Patients