A seroprevalence investigation of chicken astrovirus infections
Résumé
Two genetically different isolates of chicken astrovirus (CAstV), named CAstV612 and CAstV11672, which share low levels of antigenic relatedness in cross-indirect immunofluorescence (IIF) tests, have been identified recently. In this study, separate IIF tests for detecting antibodies to the CAstV612 and CAstV11672 isolates have been used to determine the seroprevalences of CAstV infections in 4 generations of flocks involved in broiler chicken production. CAstV antibodies were detected in 78% (73% CAstV612; 46% CAstV11672) of serum samples from UK broiler flocks and in all 10 flocks tested, indicating that infections were very common. Twenty three (96%) of 24 and 26 (93%) of 28 broiler parent flocks, aged 23-26 weeks from 3 UK organisations, were positive for antibody to CAstV612 and CAstV11672 respectively. Of 718 samples tested from these parent flocks, 415 (53%) were positive for either CAstV612 or CAstV11672 antibody. CAstV infections were also widespread in parent flocks, with screening of pooled serum samples showing that antibodies to both CAstVs were detected in flocks from 7 other UK poultry organisations and in flocks from 8 other European countries. The seropositivities for CAstVs were substantially less in grandparent (28%) and great grandparent (21%) flocks. Overall, higher seropositivies were observed for CAstV612 than for CAstV11672 in broiler, parent, GP and GGP flocks. A limited study of 99 sera from 10 turkey breeder flocks showed low level seropositivities for CAstV612 (9%) and CAstV11672 (2%), indicating that turkeys were infected with CAstVs or antigenically related viruses.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...