Stool: Clostridium difficile common antigen and toxin/toxin gene
CT2111A: Negative/Negative CT2111B:Positive/Positive
CMPT QA/QC
CT2111-A: C.difficile common antigen negative and gene/toxin negative, viable for 35 days
CT2111-B: C.difficile common antigen positive and gene/toxin positive, viable for 35 days
Reference Laboratories
CT2111-A: 8/11 labs reported both antigen and toxin negative; two labs did not test antigen but reported toxin negative; one lab reported antigen indeterminate but tested negative for toxin.
CT2111-B: 9/11 labs reported both antigen and toxin positive; two labs did not test antigen but reported toxin positive.
Participants’ results
NOTE: grading for Clostridium difficile toxin testing has changed. Please click here for more details
Table 1. CT2111A - Antigen/Toxin or Toxin gene Total Grade
negative/negative 46 Acceptable/Acceptable
not tested/negative 6 Ungraded/Acceptable
negative/not tested 1 Acceptable/Ungraded
indeterminate/negative 1 Ungraded/Acceptable
Total 54
Table 1. CT2111B - Antigen/Toxin or Toxin gene Total Grade
positive/positive 47 Acceptable/Acceptable
not tested/positive 6 Ungraded/Acceptable
indeterminate/indeterminate* 1 Ungraded/Ungraded
Total 54
*Laboratory indicated they would refer sample for further tesing.
Table 2. CT2111B - IC /PH Notification Total Grade
YES 52 Acceptable
NO * 1 Ungraded
Not applicable (reported indeterminate) 1 Ungraded
Total 54
*Lab is an outpatient laboratory and not required to report to Infection Control
Suitability for Grading
A challenge is considered suitable for grading if agreement is reached by 80 percent of selected reference group and at least 70 percent of the participants.
Antigen and toxin detection was correctly performed by at least 80 percent of reference laboratories and greater than 70 percent of all laboratories thus, both challenges were determined to be suitable for grading.
Grading: Please note that grading for Clostridium difficile toxin testing has changed. Please click here for more details
The samples are assessed for homogeneity and stability using in-house quality control methods and random selection of samples before and during production, and post sample delivery. The number of random samples selected is based on selection tables within Military standard 105E (1).
The challenge sample lot was confirmed to be homogeneous and stable for at least 15 days.
Grading of Clostridium difficile common antigen and toxin/toxin gene detection is based on a Positive / Negative result, no further statistical analysis is performed on the results beyond that described under “Suitability for grading(1) Famum NR. Acceptance sampling. In: Modern Statistical Quality Control and Improvement. Belmont, California.: Duxbury Press; 1994:305.
Stool: Clostridium difficile common antigen and toxin/toxin gene
CTxxxxA: Result/Result CTxxxxB: Result/Result
CMPT QA/QC
CTxxxx-A: C.difficile common antigen result and gene/toxin result, viable for x days
CTxxxx-B: C.difficile common antigen result and gene/toxin result, viable for x days
Reference Laboratories
CTxxxx-A:
CTxxxx-B:
Participants’ results
NOTE: grading for Clostridium difficile toxin testing has changed. Please click here for more details
(Insert table results A) [table “x” not found /]
Insert table IC/PH A if applicable [table “x” not found /]
(Insert table results B) [table “x” not found /]
Insert table IC/PH B if applicable [table “x” not found /]
NT: not tested
Suitability for Grading
A challenge is considered suitable for grading if agreement is reached by 80 percent of selected reference group and at least 70 percent of the participants.
Antigen and toxin detection was correctly performed by at least 80 percent of reference laboratories and greater than 70 percent of all laboratories thus, both challenges were determined to be suitable for grading.
Grading: Please note that grading for Clostridium difficile toxin testing has changed. Please click here for more details
The samples are assessed for homogeneity and stability using in-house quality control methods and random selection of samples before and during production, and post sample delivery. The number of random samples selected is based on selection tables within Military standard 105E (1).
The challenge sample lot was confirmed to be homogeneous and stable for at least 15 days.
Grading of Clostridium difficile common antigen and toxin/toxin gene detection is based on a Positive / Negative result, no further statistical analysis is performed on the results beyond that described under “Suitability for grading(1) Famum NR. Acceptance sampling. In: Modern Statistical Quality Control and Improvement. Belmont, California.: Duxbury Press; 1994:305.
ISO17043