Comparative analysis of 2 commercial molecular tests for the detection of gastroenteric viruses on stool samples

Our purpose was to compare the performance of 2 recently introduced molecular tests for the identification of gastrointestinal viral infections. One hundred fecal samples from pediatric patients were analyzed using 2 workflows, each including nucleic acids extraction and multiplex Real-Time PCR: Allplex™ GI-Virus Assay and FTD Viral gastroenteritis. The agreement was evaluated calculating Cohen's kappa and applying McNemar's test. Allplex and FTD assays showed 100% overall agreement for Norovirus GI/GII and Sapovirus (κ: 1.00), and 99% for Astrovirus (κ: 0.66). A lower agreement was detected for Adenovirus (89%; κ: 0.72) and Rotavirus (91%, k: 0.53), owing to samples resulted positive only with FTD test. The discrepancies were attributed to a different efficiency of extraction/amplification and to the different Adenovirus serotype specificity of the tests since Allplex detects only AdVF40 and AdVF41. FTD test should be used when non enteric adenovirus could have a clinical significance.