title: Occurrence of different subgroups of avian leukosis virus in Finnish poultry.
abstract: Ten Finnish breeding flocks were investigated for occurrence of avian leukosis virus and antibodies. The results show that field isolates representing all 4 main subgroups, A, B, C, and D, of avian leukosis virus have been identified. Antibodies to these subgroups are widespread in the country. Within 5 of the flocks antibody response to all 4 subgroups was found simultaneously, and there were individual chickens that carried antibodies against 2, 3, and in 2 cases, even, all 4 subgroups at the same time.
authors.affiliation: Department of Virology, University of Helsinki, Helsinki 29, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Sandelin
authors.forename: T
authors.initials: T
authors.lastname: Estola