2 AVIAN H10 INFLUENZA-A VIRUS-STRAINS WITH DIFFERENT PATHOGENICITY FOR MINK (MUSTELA-VISON)

We compared two strains of avian influenza A viruses of subtype H10 by exposing mink to aerosols of A/mink/Sweden/3900/84 (H10N4) naturally pathogenic for mink, or A/chicken/Germany/N/49, (H10N7). Lesions in th e respiratory tract during the first week after infection were studied and described. Both virus strains caused inflammatory reactions in th e lungs and antibody production in exposed mink but only mink/84 virus was reisolated. The lesions caused by mink/84 virus were more severe with higher area density of pneumonia, lower daily weight gain, and mo re virus in the tissues detected by immunohistochemistry. The results indicate that mink/84 (H10N4), but not chicken/49 virus (H10N7), estab lished multiple cycle replication in infected cells in the mink.