title: Single toxin detection is inadequate to diagnose Clostridium difficile diarrhea in pediatric patients.
abstract: OBJECTIVE
  Clostridium difficile is an important cause of symptomatic diarrhea in pediatric patients. The bacterium produces two toxins, although many laboratories assay for only one. We questioned this diagnostic approach when patients had positive results for C. difficile at our institution, but initially had tested negative at outside laboratories.
  
  
  METHODS
  We retrospectively analyzed relative frequencies of C. difficile toxin A alone, toxin B alone, and toxins A and B from pediatric patients with diarrhea. Results were stratified according to toxin detection and patient age.
  
  
  RESULTS
  Of 1061 specimens, 276 (26.8%) were positive for C. difficile toxin(s). Fifty-one (18.5%) were positive for toxin A alone, 133 (48.2%) for toxin B alone, and 92 (33.3%) for both toxins. Assaying for toxin B identified C. difficile infection more frequently than did assaying for toxin A (P < 0.0001). The frequency of toxin B detection was significantly higher for older children but not for infants.
  
  
  CONCLUSIONS
  Testing for C. difficile toxin A or toxin B alone will result in more frequent misdiagnosis than testing for both toxins. This practice may lead to inappropriate further invasive investigations in children, although this finding may not be applicable to adults.
authors.affiliation: Division of Gastroenterology and Nutrition, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA. kader@email.chop.edu
authors.forename: H A
authors.initials: HA
authors.lastname: Kader
authors.forename: D A
authors.initials: DA
authors.lastname: Piccoli
authors.forename: A F
authors.initials: AF
authors.lastname: Jawad
authors.forename: K L
authors.initials: KL
authors.lastname: McGowan
authors.forename: E S
authors.initials: ES
authors.lastname: Maller
mesh_terms: D000293:Adolescent; D001427:Bacterial Toxins; D002648:Child; D002675:Child, Preschool; D016360:Clostridioides difficile; D003015:Clostridium Infections / Q000175:diagnosis*; D003967:Diarrhea / Q000175:diagnosis* / Q000382:microbiology*; D006801:Humans; D007223:Infant; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D001427:Bacterial Toxins