Avian polymavirus in wild birds: genome analysis of isolates from Falconiformes and Psittaciformes

Avian polyomavirus (APV) infections have been reported to cause fatal disease in a wide range of psittacine species. Here we demonstrate APV infections in buzzards (Buteo buteo) and in a falcon (Falco tinnunculus) found dead in Germany, and in lovebirds (Agapornis pullaria) with fatal disease, wild-caught in Moçambique. APV infection in buzzards was determined by PCR amplification of parts of the viral genome followed by Southern blot hybridisation. The genomes of the isolates obtained from the falcon and one of the lovebirds proved to be very closely related to those of Budgerigar Fledgling Disease Virus (BFDV)-1, BFDV-2 and BFDV-3, isolated from budgerigar, chicken, and parakeet, respectively. A consensus sequence was delineated from the known nucleotide sequences of APV isolates. The significance of some nucleotide changes is discussed. Infectivity of all of these isolates was neutralized by antibodies directed against BFDV-1. Data presented in this investigation show that the polyomavirus isolates obtained from different avian species so far all belong to one genotype and one serotype within the proposed subgenus Avipolyomavirus of the family Papovaviridae. The designation Budgerigar Fledgling Disease Virus (BFDV) is, therefore, misleading as this virus type infects different species of birds. The name Avian Polymavirus and the abreviation APV should be adopted to all of the isolates investigated in detail at present. The possible role of birds of passage in the epidemiology in APV infections is discussed.