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Evolution of Testing Algorithms at a Tertiary Care Hospital for the Detection of Clostridium difficile Infections
BACKGROUND: Clostridium difficile-associated diarrhea (CDAD) is the commonest cause of nosocomial diarrhea. Methods for C.difficle detection include toxins or enzyme detection by immunoassays, cytotoxicity neutralization assay (CCNA) or FDA approved PCR. Due to the tedious and time consuming nature...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5631215/ http://dx.doi.org/10.1093/ofid/ofx163.1587 |
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author | Qutub, Mohammed Govindan, Parasanth Vattappillil, Anupama |
author_facet | Qutub, Mohammed Govindan, Parasanth Vattappillil, Anupama |
author_sort | Qutub, Mohammed |
collection | PubMed |
description | BACKGROUND: Clostridium difficile-associated diarrhea (CDAD) is the commonest cause of nosocomial diarrhea. Methods for C.difficle detection include toxins or enzyme detection by immunoassays, cytotoxicity neutralization assay (CCNA) or FDA approved PCR. Due to the tedious and time consuming nature of the CCNA and the suboptimal specificity and sensitivity of EIAs, these assays cannot be used as stand-alone tests. One approach of combining these assays, is by two-step algorithm, where Ag-EIAs is used as screening test and confirmation of positives either by a toxin detection enzyme immunoassays or by CCNA. Another approach is a three-step algorithm, where Ag-EIAs is used as screening test, and all positives are tested by a toxin detection EIA and if toxin detection negative, further tested either by PCR or by CCNA. Therefore we aimed to evaluate a new two-step algorithm for the detection of toxigenic CD and its role in improvement of turn-around-time. METHODS: A total of 3518 nonformed stool specimens from suspected cases of CDAD were collected. Specimens were tested either by GDH-toxin A/B ICA; or by GeneXpert C. diificile PCR as per the algorithm (Figure 1). RESULTS: Of 3518 stool specimens tested; 130 (3.70%) were positive and 2989 (84.96%) were negative by GDH-toxin A/B ICA while 399 (11.34%) required PCR. None of the negative GDH and positive toxin A/B samples tested positive by PCR. Also, none of the negative GDH and negative toxin A/B samples tested positive by PCR (Figure 2). CONCLUSION: Study indicates that when the GDH-toxin A/B ICA is used, almost 89 % of the results could be reported within 30 minutes; about 3.7 % of them being positive results and 84.96 % being negative. Confirmation of the discrepant GDH and Toxin A/B results was by PCR. The new algorithm offered rapid detection of C.difficile by ICA, judicious use of PCR and effectively reduced turnaround time. DISCLOSURES: All authors: No reported disclosures. |
format | Online Article Text |
id | pubmed-5631215 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-56312152017-11-07 Evolution of Testing Algorithms at a Tertiary Care Hospital for the Detection of Clostridium difficile Infections Qutub, Mohammed Govindan, Parasanth Vattappillil, Anupama Open Forum Infect Dis Abstracts BACKGROUND: Clostridium difficile-associated diarrhea (CDAD) is the commonest cause of nosocomial diarrhea. Methods for C.difficle detection include toxins or enzyme detection by immunoassays, cytotoxicity neutralization assay (CCNA) or FDA approved PCR. Due to the tedious and time consuming nature of the CCNA and the suboptimal specificity and sensitivity of EIAs, these assays cannot be used as stand-alone tests. One approach of combining these assays, is by two-step algorithm, where Ag-EIAs is used as screening test and confirmation of positives either by a toxin detection enzyme immunoassays or by CCNA. Another approach is a three-step algorithm, where Ag-EIAs is used as screening test, and all positives are tested by a toxin detection EIA and if toxin detection negative, further tested either by PCR or by CCNA. Therefore we aimed to evaluate a new two-step algorithm for the detection of toxigenic CD and its role in improvement of turn-around-time. METHODS: A total of 3518 nonformed stool specimens from suspected cases of CDAD were collected. Specimens were tested either by GDH-toxin A/B ICA; or by GeneXpert C. diificile PCR as per the algorithm (Figure 1). RESULTS: Of 3518 stool specimens tested; 130 (3.70%) were positive and 2989 (84.96%) were negative by GDH-toxin A/B ICA while 399 (11.34%) required PCR. None of the negative GDH and positive toxin A/B samples tested positive by PCR. Also, none of the negative GDH and negative toxin A/B samples tested positive by PCR (Figure 2). CONCLUSION: Study indicates that when the GDH-toxin A/B ICA is used, almost 89 % of the results could be reported within 30 minutes; about 3.7 % of them being positive results and 84.96 % being negative. Confirmation of the discrepant GDH and Toxin A/B results was by PCR. The new algorithm offered rapid detection of C.difficile by ICA, judicious use of PCR and effectively reduced turnaround time. DISCLOSURES: All authors: No reported disclosures. Oxford University Press 2017-10-04 /pmc/articles/PMC5631215/ http://dx.doi.org/10.1093/ofid/ofx163.1587 Text en © The Author 2017. Published by Oxford University Press on behalf of Infectious Diseases Society of America. http://creativecommons.org/licenses/by-nc-nd/4.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact journals.permissions@oup.com |
spellingShingle | Abstracts Qutub, Mohammed Govindan, Parasanth Vattappillil, Anupama Evolution of Testing Algorithms at a Tertiary Care Hospital for the Detection of Clostridium difficile Infections |
title | Evolution of Testing Algorithms at a Tertiary Care Hospital for the Detection of Clostridium difficile Infections |
title_full | Evolution of Testing Algorithms at a Tertiary Care Hospital for the Detection of Clostridium difficile Infections |
title_fullStr | Evolution of Testing Algorithms at a Tertiary Care Hospital for the Detection of Clostridium difficile Infections |
title_full_unstemmed | Evolution of Testing Algorithms at a Tertiary Care Hospital for the Detection of Clostridium difficile Infections |
title_short | Evolution of Testing Algorithms at a Tertiary Care Hospital for the Detection of Clostridium difficile Infections |
title_sort | evolution of testing algorithms at a tertiary care hospital for the detection of clostridium difficile infections |
topic | Abstracts |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5631215/ http://dx.doi.org/10.1093/ofid/ofx163.1587 |
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