Challenges to accurate diagnosis of pediatric C difficile infection

Borali E, De Giacomo C. Clostridium Difficile Infection in Children: a Review. J Pediatr Gastroenterol Nutr. 2016 May 13. [Epub ahead of print]

“There is strong evidence of a significant increase in the incidence of paediatric CDI in recent years. Some important considerations regarding age and well-known clinical risk factors for the disease have to be made by paediatricians when considering whether to test children for CDI. However, the infection is potentially acquired from the community in the majority of cases, and sometimes without a preceding history of antibiotic use or underlying associated pathologies. The in-vitro diagnosis is complicated by the redundancy of methods and hence, the results must be carefully evaluated against the clinical background.”

Full-text for Children’s and Emory users.

Kociolek LK, et al. Clinical and Microbiologic Assessment of Cases of Pediatric Community-associated Clostridium difficile Infection Reveals Opportunities for Improved Testing Decisions. Pediatr Infect Dis J. 2016 Feb;35(2):157-61.

Many children diagnosed with CA-CDI by PCR lack CDI risk factors and have discordant results when additional CDI testing methods are performed, suggesting overdiagnosis of CDI in children with community-onset diarrhea. More selective CDI testing of low-risk pediatric patients is needed to more accurately diagnose CDI and limit unnecessary CDI antibiotic treatment in children.

Full-text for Children’s and Emory users.

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EBM Review: Detection of Kingella kingae osteoarticular infections in children by oropharyngeal swab PCR.

Ceroni D, Dubois-Ferriere V, Cherkaoui A, Gesuele R, Combescure C, Lamah L, Manzano S, Hibbs J, Schrenzel J. Detection of Kingella kingae osteoarticular infections in children by oropharyngeal swab PCR. Pediatrics. 2013 Jan;131(1):e230-5.

Full-text for Children’s and Emory users.

OBJECTIVE: The purpose of this study was to investigate if oropharyngeal swab polymerase chain reaction (PCR) could predict osteoarticular infection (OAI) due to Kingella kingae in young children. 

METHODS: One hundred twenty-three consecutive children aged 6 to 48 months presenting with atraumatic osteoarticular complaints were prospectively studied. All had a clinical evaluation, imaging, and blood samples. Blood and oropharyngeal specimens were tested with a PCR assay specific for K kingae. OAI was defined as bone, joint, or blood detection of pathogenic bacteria, or MRI consistent with infection in the absence of positive microbiology. K kingae OAI was defined by blood, bone, or synovial fluid positivity for the organism by culture or PCR.

RESULTS: Forty children met the OAI case definition; 30 had K kingae OAI, 1 had another organism, and 9 had no microbiologic diagnosis. All 30 oropharyngeal swabs from the K kingae case patients and 8 swabs from the 84 patients without OAI or with OAI caused by another organism were positive. The sensitivity and specificity of the oropharyngeal swab PCR assay for K kingae were 100% and 90.5%, respectively.

CONCLUSIONS: Detection of K kingae DNA in oropharyngeal swabs of children with clinical findings of OAI is predictive of K kingae OAI. If these findings are replicated in other settings, detection of K kingae by oropharyngeal swab PCR could improve the recognition of OAI.

Reviewed by Kristina Betters, MD and Amelia Thompson, MD

Main Points:

  • Kingella kingae is a leading cause of osteoarticular infections in children less than 48 months of age
  • Kingella kingae is very difficult to isolate in cultures- often causative organism in culture negative osteoarticular infections; often PCR of joint fluid/aspirate needed to ascertain diagnosis
  • Investigators attempting to use oral pharyngeal PCR as non-invasive diagnostic test for diagnosing K. kingae osteoarticular infections
  • All subjects tested presented with concern for osteoarticular infection (no healthy controls in study)
  • In study population very high rate of K. kingae infection (and low staph infection rate). May not be applicable to our treatment population in Atlanta.
  • Oral pharyngeal PCR had high sensitivity/specificity, but somewhat low sample size and lower positive predictive value and negative predictive value
  • Potential future directions: determining asymptomatic oral carriage rate of K. kingae, increasing sample size, expanding to multi-center trial for more heterogeneous sample