Background: Among high-risk pediatric patients the epidemiology and transmission of CDI is less well reported than among adults despite advances in access to molecular techniques. In this report we describe the epidemiology of CDI by multilocus sequence type (MLST) in pediatric oncology patients.
Methods: Demographic and epidemiologic information was extracted from the MSKCC infection control surveillance database (CKM) for all laboratory identified CDI cases in pediatric patients from Jan 1 to Dec 31, 2015. Data were correlated with MLST performed on retrieved isolates. Community onset-facility associated (COFA) designation was based on prior exposure to our institution within 8 weeks before a positive test. CDI testing remained via single-step PCR assay on diarrheal stool samples throughout the study period.
Results: During the 12 month study period CDI was diagnosed in 96 unique patients. 62 were community-acquired and 30 were hospital-onset (HO). The overall HO rate was 2.6/1000 patient days. 27 cases were COFA. When examined by age, a majority of the cases (36.5%) occurred among children < 3 years of age (Figure 1). Cancer specific rates of CDI were highest for BMT and neuroblastoma (6.6 and 6.7 per 1000 visits) (Figure 2). Among 96 cases, 84 were genotyped by MLST 31 distinct strains were identified with a distribution similar to the dominant STs in our adult CDI cases (Figure 3). 25 patients had paired episodes and samples collected. 13 (52%) had the same MLST, likely representing relapse, and 12 had a different MLST, likely representing reinfection. Among hospitalized cases <3 years of age, transmission was suspected to have occurred among at least 6 cases with direct or unit based contact.
Conclusion: Pediatric oncology patients constitute a high risk population for CDI with rates 1.5 times higher than our average NHSN rate. Children with BMT and neuroblastoma have the highest risk, likely due to a combination of factors: age <3 y, longer hospital stay and antibiotic exposure. The frequency distribution of dominant strains among pediatric CDI is strikingly similar to adult CDI cases at our institution. Although it can be challenging to distinguish between colonization and infection in children <3 yo they constitute an important reservoir for onward transmission.
A. Aslam, None
M. Kamboj, None