CDI Diagnosis Research Articles

Community-associatedClostridium difficileInfections, Monroe County, New York, USA

We conducted active sentinel surveillance in Monroe County, New York, USA, to compare incidence of community-associated Clostridium difficile infections (CA-CDIs) with that of health care-associated infections (HA-CDIs) and identify exposure and strain type differences between CA and HA cases. Patients positive for C. difficile toxin and with no documented health care exposure in the previous 12 weeks were defined as possible CA case-patients. Patients with onset in a health care setting or recent health care exposure were defined as HA case-patients. Eighteen percent of CDIs were CA; 76% were in persons who reported antimicrobial drug use in the 12 weeks before CDI diagnosis. Strain type distribution was similar between CA and HA cases; North American pulsed-field 1 was the primary strain (31% CA, 42% HA; p = 0.34). CA-CDI is an emergent disease affecting patients recently exposed to antimicrobial drugs. Community strains are similar to those found in health care settings.

P418 Extraintestinal manifestations in inflammatory bowel disease; the prevalence in tertiary referral center

Background: CDI is the main cause of antibiotic associated infectious diarrhea. Incidence, severity and burden on the healthcare system related to CDI have increased in last decade in many industrialized countries. Epidemiological data of CDI are scarce in Southern Europe. Aims: To evaluate incidence and secular trend of nosocomial CDI between 2000 and 2009 in two Spanish referral hospitals. To analyze the highest incidence rates across specialties. Methods: Setting: Two referral hospitals in the Barcelona metropolitan area. Design: Retrospective surveillance study. Laboratory CDI diagnosis: Positive toxigenic culture and/or toxin detection in fecal samples using cell citoxicity neutralization assay. Patients: All in-patients from whom an appropriate fecal sample was submitted for CDI study between January 2000 and December 2009 were included. Nosocomial CDI case definition: A nosocomial CDI case was defined by the presence of either a positive stool test for C. difficile toxin or toxigenic C. difficile more than 48 hours after admission and that not have been diagnosed of CDI within the previous 28 days. Results: We identified 278 cases. Between 2000 and 2005 CDI incidence remained stable (0.52 and 0.54 cases/10.000 inpatient days in 2000 and 2005 respectively). During second half of this decade a four fold increase in incidence occurred (0.79, 1.48, 1.95 y 2.33 cases/10.000 in-patient days in 2006, 2007, 2008 y 2009 respectively). During de same period there was an increased hospitalary antibiotics consumption (from 56 to 67 defined daily doses/100 in-patient days between 2000 and 2009) that correlated with nosocomial CDI incidence (r = 0.98, p < 0.001). Hematology, ICU, Infectious Diseases and Gastroenterology Departments had the highest CDI incidence rates. Conclusions: CDI incidence has quadruplicate during second half of last decade coinciding with an increased use of antibiotics. Our results highlight the importance of CDI surveillance in hospitals, specially among high risk departments.

Laboratory Testing for Clostridium difficile Infection

Clostridium difficile infection (CDI) is changing as evidenced by increasing virulence, rising incidence, unresponsiveness to metronidazole therapy, and worse outcomes. Thus, it is critical that CDI diagnosis be accurate so ongoing epidemiology, disease prevention, and treatment remain satisfactory. We tested 10 diagnostic assays, including 1 commercial real-time polymerase chain reaction (qPCR) test for the laboratory detection of toxigenic C difficile on 1,000 stool samples. Sensitive culture for toxigenic C difficile using 2 types of media with broth enrichment defined the reference standard. For the study, 1,000 tests were performed on samples from 919 patients. Of the samples, 146 contained evidence for toxigenic C difficile and represented the true-positive results. Only the US Food and Drug Administration-cleared qPCR assay (Becton Dickinson, Franklin Lakes, NJ) and 1 glutamate dehydrogenase test (TechLab, Blacksburg, VA) were not statistically inferior to culture in sensitivity. The common enzyme immunoassay tests all had sensitivity values less than 50%. Clinical laboratory professionals need to seriously consider their diagnostic testing and use the assays that perform best for the detection of CDI.

A Retrospective Analysis of Risk Factors for Severe Clostridium Difficile Infection In Acute Leukemia and Aggressive Lymphoma.

AbstractAbstract 3797 Introduction and Goals.Clostridium difficile infection (CDI) is increasing in frequency and severity. Risk factors for severity of illness and treatment recommendations for patients with concurrent aggressive hematologic malignancies have not been investigated, despite data showing that this population experiences a high rate of CDI. The goal of this study was to assess mortality associated from CDI as well as risk factors for severe CDI in a population of patients with acute hematologic malignancies. Methods.Ninety-three cases of CDI among 78 patients with active acute leukemia or aggressive lymphoma at the University of Virginia (UVa) Health System from 2004–2009 were studied retrospectively. Rates of all-cause mortality, attributable mortality secondary to CDI (defined as CDI with at least one of the following: active diarrhea, toxic megacolon, or pseudomembranes on colonoscopy at time of death), and a composite outcome (defined as at least one of the following: attributable mortality, ICU stay from CDI, pseudomembranous colitis, toxic megacolon, or colectomy) were assessed as adverse outcomes. The following potential risk factors for severe CDI were investigated, adjusting for age: onset and duration of neutropenia, exposure to high dose cytarabine, number of antimicrobials given, exposure to fluoroquinolone prophylaxis for neutropenic fever, and a designation of severe CDI as previously described (at least two of the following: white blood count >15,000 cells/mL, age >60 years, albumin <2.5 g/dL, temperature >38.3° C, or one of the following: ICU stay or pseudomembranous colitis). Results.All-cause mortality was 21.7%. CDI-attributable mortality was 14.1%. The rate of the composite outcome was 20.3%. All-cause mortality was higher in patients with leukemia and lymphoma than for all other patients hospitalized at this institution with CDI in 2008 (12.5% all-cause mortality, 76/610, p=0.015, 95% CI [13.2, 32.6]). Duration of neutropenic episode >14 days and neutropenia at diagnosis of CDI were associated with increased risk of attributable mortality (OR 3.12, 95% CI [0.82, 11.92], p=0.09; OR 3.39, 95% CI [0.57, 20.05], p=0.11). Cumulative duration of neutropenia >21 days was not associated with increased risk in adverse outcomes. Designation of severe CDI predicted an increase in all-cause mortality (OR 6.7, 95% CI [2.1, 21.5], p <0.001), attributable mortality (OR 11.5, 95% CI [2.3, 57.5], p <0.001), and the composite outcome, (OR 19.3, 95% CI [5.5, 74.7], p <0.001). Fluoroquinolone prophylaxis for neutropenic fever, high dose cytarabine, induction chemotherapy, or receipt of more than 2 concurrent antimicrobials were not associated with increased risk of all-cause mortality, attributable mortality or the composite outcome. Discussion.Patients with acute hematologic malignancies and concurrent CDI were at increased risk of all-cause and CDI-attributable mortality compared with similar data from UVa of all hospitalized patients. Prolonged neutropenia at time of CDI diagnosis was associated with an increased risk of CDI-attributable mortality, although this result was not statistically significant. Established criteria for diagnosing severe CDI were helpful at predicting poor outcomes in this population. Seven of the 10 neutropenic patients who died in this study did not receive oral vancomycin. Neutropenic patients with CDI may benefit from initial treatment with oral vancomycin instead of metronidazole, especially if other criteria for severe illness are present. Future research may assess effectiveness of oral vancomycin as initial treatment for CDI in neutropenic patients. Disclosures:No relevant conflicts of interest to declare.