Can a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection?
Abstract Background Diagnosis of C. difficile infection (CDI) is controversial because of the many laboratory methods available and their lack of ability to distinguish between carriage, mild or severe disease. Here we describe whether a low C. difficile toxin B nucleic acid amplification test (NAAT...
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| Format: | Article |
| Language: | English |
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BMC
2017-12-01
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| Series: | Antimicrobial Resistance and Infection Control |
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| Online Access: | http://link.springer.com/article/10.1186/s13756-017-0283-z |
| _version_ | 1818341400734859264 |
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| author | Mark I. Garvey Craig W. Bradley Martyn A. C. Wilkinson Elisabeth Holden |
| author_facet | Mark I. Garvey Craig W. Bradley Martyn A. C. Wilkinson Elisabeth Holden |
| author_sort | Mark I. Garvey |
| collection | DOAJ |
| description | Abstract Background Diagnosis of C. difficile infection (CDI) is controversial because of the many laboratory methods available and their lack of ability to distinguish between carriage, mild or severe disease. Here we describe whether a low C. difficile toxin B nucleic acid amplification test (NAAT) cycle threshold (CT) can predict toxin EIA, CDI severity and mortality. Methods A three-stage algorithm was employed for CDI testing, comprising a screening test for glutamate dehydrogenase (GDH), followed by a NAAT, then a toxin enzyme immunoassay (EIA). All diarrhoeal samples positive for GDH and NAAT between 2012 and 2016 were analysed. The performance of the NAAT CT value as a classifier of toxin EIA outcome was analysed using a ROC curve; patient mortality was compared to CTs and toxin EIA via linear regression models. Results A CT value ≤26 was associated with ≥72% toxin EIA positivity; applying a logistic regression model we demonstrated an association between low CT values and toxin EIA positivity. A CT value of ≤26 was significantly associated (p = 0.0262) with increased one month mortality, severe cases of CDI or failure of first line treatment. The ROC curve probabilities demonstrated a CT cut off value of 26.6. Discussions Here we demonstrate that a CT ≤26 indicates more severe CDI and is associated with higher mortality. Samples with a low CT value are often toxin EIA positive, questioning the need for this additional EIA test. Conclusions A CT ≤26 could be used to assess the potential for severity of CDI and guide patient treatment. |
| first_indexed | 2024-12-13T15:58:12Z |
| format | Article |
| id | doaj.art-f3259586d9764dfc971fa8c8ab7ba8c5 |
| institution | Directory Open Access Journal |
| issn | 2047-2994 |
| language | English |
| last_indexed | 2024-12-13T15:58:12Z |
| publishDate | 2017-12-01 |
| publisher | BMC |
| record_format | Article |
| series | Antimicrobial Resistance and Infection Control |
| spelling | doaj.art-f3259586d9764dfc971fa8c8ab7ba8c52022-12-21T23:39:16ZengBMCAntimicrobial Resistance and Infection Control2047-29942017-12-01611810.1186/s13756-017-0283-zCan a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection?Mark I. Garvey0Craig W. Bradley1Martyn A. C. Wilkinson2Elisabeth Holden3University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital BirminghamUniversity Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital BirminghamUniversity Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital BirminghamUniversity Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital BirminghamAbstract Background Diagnosis of C. difficile infection (CDI) is controversial because of the many laboratory methods available and their lack of ability to distinguish between carriage, mild or severe disease. Here we describe whether a low C. difficile toxin B nucleic acid amplification test (NAAT) cycle threshold (CT) can predict toxin EIA, CDI severity and mortality. Methods A three-stage algorithm was employed for CDI testing, comprising a screening test for glutamate dehydrogenase (GDH), followed by a NAAT, then a toxin enzyme immunoassay (EIA). All diarrhoeal samples positive for GDH and NAAT between 2012 and 2016 were analysed. The performance of the NAAT CT value as a classifier of toxin EIA outcome was analysed using a ROC curve; patient mortality was compared to CTs and toxin EIA via linear regression models. Results A CT value ≤26 was associated with ≥72% toxin EIA positivity; applying a logistic regression model we demonstrated an association between low CT values and toxin EIA positivity. A CT value of ≤26 was significantly associated (p = 0.0262) with increased one month mortality, severe cases of CDI or failure of first line treatment. The ROC curve probabilities demonstrated a CT cut off value of 26.6. Discussions Here we demonstrate that a CT ≤26 indicates more severe CDI and is associated with higher mortality. Samples with a low CT value are often toxin EIA positive, questioning the need for this additional EIA test. Conclusions A CT ≤26 could be used to assess the potential for severity of CDI and guide patient treatment.http://link.springer.com/article/10.1186/s13756-017-0283-zClostridium DifficileNAATEIASeverityMortalityC. difficile Infection |
| spellingShingle | Mark I. Garvey Craig W. Bradley Martyn A. C. Wilkinson Elisabeth Holden Can a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection? Antimicrobial Resistance and Infection Control Clostridium Difficile NAAT EIA Severity Mortality C. difficile Infection |
| title | Can a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection? |
| title_full | Can a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection? |
| title_fullStr | Can a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection? |
| title_full_unstemmed | Can a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection? |
| title_short | Can a toxin gene NAAT be used to predict toxin EIA and the severity of Clostridium difficile infection? |
| title_sort | can a toxin gene naat be used to predict toxin eia and the severity of clostridium difficile infection |
| topic | Clostridium Difficile NAAT EIA Severity Mortality C. difficile Infection |
| url | http://link.springer.com/article/10.1186/s13756-017-0283-z |
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