Sara Podczervinski

Evaluating risk factors for Clostridium difficile infection in adult and pediatric hematopoietic cell transplant recipients

BackgroundAlthough hematopoietic cell transplant (HCT) recipients are routinely exposed to classic risk factors for Clostridium difficile infection (CDI), few studies have assessed CDI risk in these high-risk patients, and data are especially lacking for pediatric HCT recipients. We aimed to determine incidence and risk factors for CDI in adult and pediatric allogeneic HCT recipients.MethodsCDI was defined as having diarrhea that tested positive for C. difficile via PCR, cytotoxin assay, or dual enzyme immunoassays. We included all patients who received an allogeneic HCT from 2008 to 2012 at the Fred Hutchinson Cancer Research Center; those <1 year old or with CDI within 8 weeks pre-HCT were excluded. Patients were categorized by transplanting hospital (“adult” or “pediatric”) and followed for 100 days post-HCT.ResultsOf 1182 HCT recipients, CDI was diagnosed in 17 % (33/192) of pediatric recipients for an incidence of 20 per 10,000 patient-days, and 11 % (107/990) of adult recipients for an incidence of 12 per 10,000. Pediatric recipients were diagnosed a median of 51 days (interquartile range [IQR]: 5, 72) after HCT and adults at 16 days (IQR = 5, 49). Compared with calendar year 2008, pediatric recipients transplanted in 2012 were at increased risk for CDI (hazard ratio [HR] = 3.99, p =.02). Myeloablative conditioning increased CDI risk in adult recipients (HR = 1.81, p =.005).ConclusionsPediatric and adult allogeneic recipients are at high risk of CDI post-HCT, particularly adult recipients of myeloablative conditioning. Differences in CDI incidence between children and adults may have resulted from exposure differences related to age; therefore, separately evaluating these groups should be considered in future CDI studies.

Evaluation of routine pretransplantation screening for methicillin-resistant Staphylococcus aureus in hematopoietic cell transplant recipients

Methicillin-resistant Staphylococcus aureus (MRSA) screening guidelines for hematopoietic cell transplant (HCT) recipients are not well defined. Retrospective assessment of standardized pretransplantation MRSA screening in a large single-center cohort of HCT recipients demonstrated that colonization was uncommon, and that no colonized patients developed posttransplantation invasive complications.

Bacterial foodborne infections after hematopoietic cell transplantation.

Diarrhea, abdominal pain, and fever are common among patients undergoing hematopoietic cell transplantation (HCT), but such symptoms are also typical with foodborne infections. The burden of disease caused by foodborne infections in patients undergoing HCT is unknown. We sought to describe bacterial foodborne infection incidence after transplantation within a single-center population of HCT recipients. All HCT recipients who underwent transplantation from 2001 through 2011 at the Fred Hutchinson Cancer Research Center in Seattle, Washington were followed for 1 year after transplantation. Data were collected retrospectively using center databases, which include information from transplantation, on-site examinations, outside records, and collected laboratory data. Patients were considered to have a bacterial foodborne infection if Campylobacter jejuni/coli, Listeria monocytogenes, E. coli O157:H7, Salmonella species, Shigella species, Vibrio species, or Yersinia species were isolated in culture within 1 year after transplantation. Nonfoodborne infections with these agents and patients with pre-existing bacterial foodborne infection (within 30 days of transplantation) were excluded from analyses. A total of 12 of 4069 (.3%) patients developed a bacterial foodborne infection within 1 year after transplantation. Patients with infections had a median age at transplantation of 50.5 years (interquartile range [IQR], 35 to 57), and the majority were adults ≥18 years of age (9 of 12 [75%]), male gender (8 of 12 [67%]) and had allogeneic transplantation (8 of 12 [67%]). Infectious episodes occurred at an incidence rate of 1.0 per 100,000 patient-days (95% confidence interval, .5 to 1.7) and at a median of 50.5 days after transplantation (IQR, 26 to 58.5). The most frequent pathogen detected was C. jejuni/coli (5 of 12 [42%]) followed by Yersinia (3 of 12 [25%]), although Salmonella (2 of 12 [17%]) and Listeria (2 of 12 [17%]) showed equal frequencies; no cases of Shigella, Vibrio, or E. coli O157:H7 were detected. Most patients were diagnosed via stool (8 of 12 [67%]), fewer through blood (2 of 12 [17%]), 1 via both stool and blood simultaneously, and 1 through urine. Mortality due to bacterial foodborne infection was not observed during follow-up. Our large single-center study indicates that common bacterial foodborne infections were a rare complication after HCT, and the few cases that did occur resolved without complications. These data provide important baseline incidence for future studies evaluating dietary interventions for HCT patients.