Evaluation of ELISA and electron microscopy for the detection of coronavirus and rotavirus in bovine faeces.

Enzyme-linked immunosorbent assay (ELISA) was compared with electron microscopy in the examination of faeces from experimental calves and showed 100 per cent agreement in the detection of 19 bovine coronavirus and 15 bovine rotavirus electron microscope positive samples. In a limited field survey of calf diarrhoea 75 selected faeces were examined independently by ELISA and electron microscopy and the agreement between the two tests was 95 per cent for coronavirus and 84 per cent for rotavirus. A further comparison was made with 74 samples submitted for routine diagnosis and this yielded agreements of 82 per cent (coronavirus) and 89 per cent (rotavirus). Factors contributing to discrepant results were examined and the relative advantages and disadvantages of the two tests for routine detection of these enteric viruses are discussed.