Evaluation of a new fast in-house Real-Time PCR assay for detecting both Norovirus and toxigenic Clostridium difficile using fecal sample and rectal swab.

BACKGROUND

Norovirus and toxigenic Clostridium difficile infections are the 2 most common causes of infectious gastroenteritis. Rapid and reliable detection of these to microorganisms is important to assess if contact precautions are indicated to prevent spreading and reduce cost of isolation.

METHODS

This study determines sensitivity and specificity of a new fast in-house PCR assay used on BD MAX platform to detect both norovirus and C difficile in 1 turn-over in clinical context. Furthermore, fecal samples as well as rectal swabs were used as analysis material to determine the accuracy of the new assay on a fecal samples and rectal swabs compared with standard methods.

RESULTS

From 227 included patients, 143 rectal swabs and 135 fecal samples obtained. The new in-house PCR showed a sensitivity of 73.3% and a specificity of 99.2% for norovirus on a fecal sample and a sensitivity of 57.1% and specificity 99.1% of for norovirus on a rectal swab. For C difficile a sensitivity of 100% and specificity of 100% on a fecal sample and a sensitivity of 90.9% and a specificity of 99.1% on a rectal swab was shown. The time consumption for detecting the 2 enteropathogens was reduced by half by using the new assay.

CONCLUSIONS

The new assay shows an acceptable sensitivity and specificity for C difficile and an acceptable specificity for norovirus when analysis was done on fecal samples and reduces half of the time consumption. Further research is needed to improve the accuracy of the new in-house PCR before clinical implication.