Detection and partial genetic characterisation of novel avi- and siadenoviruses in racing and fancy pigeons (Columba livia domestica).

Up to now, only a single adenovirus (AdV) isolate seemingly specific for pigeons, hence named pigeon AdV-1 (PiAdV-1), has been characterised at DNA sequence level. In the present work, the prevalence and diversity of AdVs occurring in domestic pigeon were examined by a survey performed on randomly collected samples using a very efficient, consensus nested PCR targeting the viral DNA polymerase gene. The newly detected viruses were characterised by sequencing and phylogeny analysis. Amplification of additional genome fragments was attempted by the use of several other PCR methods aiming at the hexon gene. During a 4-year survey, samples from dead or live, healthy pigeons originating from 27 lofts were examined in Hungary. Almost 50% of the samples (48 out of 97) proved to be positive for AdV. Sequence analysis revealed the presence of four hitherto unknown pigeon AdV types. PiAdV-1 was also identified in one sample. Two novel viruses named PiAdV-2 and -3 were found to belong to the genus Aviadenovirus, and two other novel types (PiAdV-4 and -5) to the genus Siadenovirus. This is the first report on the occurrence of siadenoviruses in birds belonging to the order Columbiformes. Approximately two-thirds of the PiAdV-2 genome was sequenced and analysed.