SURVEY OF ROTAVIRUS INFECTION IN A DAIRY-HERD - COMPARISON BETWEEN POLYACRYLAMIDE-GEL ELECTROPHORESIS AND 2 COMMERCIAL TESTS

A survey of rotavirus infection in a dairy herd with a history of neon atal diarrhoea was carried out. Faecal samples taken from 15 cows befo re and after calving as well as faeces taken from their calves daily f rom birth to two weeks of life were tested for rotavirus by polyacryla mide gel electrophoresis (PAGE) and compared with an ELISA and a latex agglutination commercial test. Rotavirus excretion was not detected i n faeces from cows around parturition by any of the three tests. Howev er, all of their calves shed rotaviruses during the observation period . The onset of rotavirus excretion determined by PAGE ranged from day 2 to day 8 of life (day 4.8 +/- 1.8 on average) and lasted for 4 to 7 days (5.3 +/- 1.1 days on average). Chi-square test showed a significa nt association (P = 0.0001) between the presence of rotavirus and the altered consistency of calves faeces. All the three tests showed simil ar results (overall agreement 92.5%) but discrepancies were detected m ainly at the beginning or at the end of the rotavirus excretion period . Results obtained with both commercial kits closely paralleled each o ther and parameters other than sensitivity, specificity, diagnostic ac curacy or predictive values have to be considered as selection criteri a.