Pseudoreplica electron microscopy for the detection of rotavirus: comparison with high-speed centrifugation electron microscopy and ELISA.

Three-hundred and sixty-three stool specimens from patients with diarrhoea were examined for rotaviruses to compare the sensitivity of the pseudoreplica technique (PSD-EM) to that of high-speed centrifugation EM (HSC-EM) in relation to a commercially available (Rotazyme, Abbott) enzyme-linked immunosorbent assay (ELISA). In ELISA-positive cases, both methods were of equal sensitivity. However, in borderline (+/-) and ELISA-negative specimens, PSD-EM detected 31 of 48 (64.6%) and 18 of 229 (8%) positive specimens respectively, compared to only 22 of 48 (45.8%) and one of 229 (0.4%) positives detected by HSC-EM. PSD-EM detected a significantly higher number of positives compared to HSC-EM (p less than 0.05). In view of its simplicity, sensitivity and the fact that a relatively large number of specimens could be processed compared to HSC-EM, we consider that PSD-EM is a much better procedure for routine screening and diagnosis of viral gastroenteritis than HSC-EM.