Objectives disease (rCDI) in children have not been well established. (OR=3.39 95 CI=1.52-7.85) recent surgery (OR=2.40 95 CI=1.05-5.52) and the number of antibiotic exposures by class (OR=1.33 95 CI=1.01-1.75) were significantly associated with recurrent disease in children. Conclusions The rate of recurrent infection in children was 22%. Recurrence was significantly associated with the risk factors of malignancy recent surgery and the number of antibiotic exposures by class. infection (CDI) recent studies have demonstrated that CDI is currently on the rise in children in both inpatient and outpatient settings.2 3 In the last ten years the rate of pediatric hospitalization with CDI has nearly doubled.4 In adults the treatment of CDI is complicated by a very high rate of recurrent disease Tetrodotoxin with estimates of 20-30% of patients experiencing a recurrence and multiple occurrences associated with increasing morbidity.5-7 Prior studies in adults have demonstrated that after a single episode of recurrence 45 to 65% of patients will have repeated episodes of CDI that may continue over a period of years.8 6 9 Recurrent CDI (rCDI) is often poorly responsive to treatment requiring additional medications longer courses of therapy additional in-hospital contact Tetrodotoxin procedures substantially increased medical costs as well as increased risk of morbidity and mortality. In one study the treatment of recurrent episodes of CDI required an average of 265 additional days/patient of vancomycin and 19.7 days/patient of metronidazole.8 The additional medical care and costs associated with rCDI are substantial. Studies have begun to define important risk factors for rCDI in adults. A meta-analysis identified age greater than 65 years old the use of concurrent antibiotics and the use of gastric acid suppressants to increase the risk of rCDI in adults.10 Other studies have identified low serum anti-toxin antibody levels and hospital exposures as important risk factors for recurrence.11-13 Recent attempts have been made to create a clinical risk prediction model in adults to help determine the risk of recurrent disease at the time of the initial contact with a healthcare worker.14 There is a paucity of data however regarding risk factors for rCDI in children. While concurrent antibiotics and community-associated CDI were recently shown to be associated with an increased likelihood of rCDI in a pediatric population 15 a comprehensive assessment of host factors that govern rCDI risk is needed. The purpose of the current study is to identify independent risk factors for rCDI in children using Tetrodotoxin rigorous statistical methods applied to a retrospective cohort from a large tertiary care children’s hospital. Tetrodotoxin Methods Patient Selection With institutional review board exemption a pediatric cohort was retrospectively compiled of 295 patients who had an episode of CDI based on positive laboratory testing at Monroe Carell Jr. Children’s Hospital at Vanderbilt (MCJCHV) from January 1 2007 through December 31 2011 in both inpatient and outpatient settings. The episode of CDI was confirmed to be the primary infection and not a recurrence through review of the medical record. The outcome of interest was rCDI defined as a recurrence of symptoms and positive testing for occurring ≤60 days from the completion of the primary treatment Tetrodotoxin for CDI. During all but the last two months of the study period laboratory testing for IL12B consisted of an enzyme immunoassay for toxin (Meridian Bioscience Premier). In November 2011 DNA amplification (Illumigene assay ARUP laboratories) was begun. Eligible patients were between the ages of 12 months to <18 years with medically documented diarrhea and confirmatory laboratory testing. The description of diarrhea needed to include >1 episode of stooling in a 24 hour period with stools described as “loose ” “watery ” or “unformed.” Children less than 12 months of age were excluded from the Tetrodotoxin study due to the known high rate of asymptomatic colonization in this demographic.16 Patients were excluded from the study if they were missing follow-up.