Comparative analysis of monoclonal antibody based enzyme immunoassay, modified genome electrophoresis & electron microscopy procedures for rotavirus diagnosis from faecal specimens.

Background & Objectives: Reliable and rapid diagnosis of rotavirus infection is necessary for patient management. Several newly introduced commercial enzyme immunoassays (ELISAs) have been evaluated using direct electron microscopy (DEM) with or without direct ultracentrifugation as the standard reference method, and have shown varying results.

Methods: In the present study we compared the diagnostic efficacy of the three methods viz., monoclonal antibody (MAb) ELISA, modified polyacrylamide gel electrophoresis (PAGE) and DEM without ultracentrifugation in the detection of rotaviruses from 211 stool specimens. The data were analysed by two latent class model (2LC) in the absence of a gold standard reference method.

Results: Rotavirus was detected in 42 specimens by MAb-ELISA; in 40 specimens by PAGE and in 33 specimens by DEM. The estimates of sensitivities and specificities of the three methods were analysed by 2LC method. The analysis revealed no significant variation among the three methods. However, DEM was found with a comparatively lesser sensitivity over the other two methods.

Interpretation & Conclusions: Though DEM was found to be relatively less sensitive than the other two methods, the differences were not significant, and all the three methods were highly specific. Moreover, DEM has the additional advantage of detecting non-group A and other gastroenteritis viruses. The findings suggest the use of highly sensitive and specific MAb-ELISA and PAGE in parallel to detect group A, non-group A and atypical rotavirus infection in the population.