Occurrence of avian bornavirus infection in captive psittacines in various European countries and its association to proventricular dilatation disease

Abstract

Abstract A total of 1,442 alive and 73 dead birds out of 215 bird collections in Spain, Germany, Italy, United Kingdom and Denmark were tested for avian bornavirus (ABV) infection by four different methods. The majority of the birds were psittacines belonging to 54 different genera of the order Psittaciformes. In total, 22.8% of the birds reacted positive for ABV in at least one of the tests. Combined testing of swabs from crop and cloaca and serum for the diagnosis of ABV infection in alive birds revealed that virus shedding and antibody production coincided in only one fifth of the positive birds so that the examination of these three samples is recommended for reliable ABV diagnostics. By statistical analysis of this large number of samples, the ABV infection proved to be highly significant (p<0.001) associated with pathohistologically confirmed proventricular dilatation disease (PDD) in dead birds as well as with clinically assumed PDD in alive birds. However, ABV infection was also detected in psittacines without pathological lesions or clinical signs of PDD. Twelve non-psittacine birds belonging to the genera Aburria, Ciconia, Geopelia, Leucopsar and Pavo were tested negative for ABV infection. Within the order of Psittaciformes, birds belonging to 33 different genera reacted positive for ABV. In 16 of these psittacine genera the ABV infection was demonstrated for the first time. The detection of ABV in captive psittacines from several European countries suggests a pan-European occurrence of this infection. This study emphasizes the widespread occurrence of clinically variable ABV infections in Europe by analysing a large number of specimens from a broad range of bird species in several assays.