Detection of astrovirus infection in pigeons (Columbia livia) during an outbreak of diarrhoea

Avian astrovirus infections are widespread in many countries, and infections have been linked to enteritis and increased mortality in young poultry. Although pigeons are treated as an important poultry product in some countries, their diseases are often poorly understood and astrovirus infection in pigeons has not been reported. In the present study, faecal samples were collected during an outbreak of gastrointestinal illness in a population of Shanghai pigeons. The samples were examined for astroviruses by reverse transcription-polymerase chain reaction. Eighty-nine per cent (40/45) and 4% (2/45) were found to be positive for avian nephritis virus (ANV) and chicken astrovirus, respectively. One positive sample indicated a co-infection with both ANV and chicken astrovirus. Phylogenetic analysis based on the partial polymerase gene sequence and full-length capsid protein from published avian astrovirus sequences in GenBank revealed that the pigeon viruses detected in this study were evolutionarily closely related to chicken ANV. The present study provided evidence for the presence of astrovirus in pigeons and suggests that cross-infection between pigeons and commercial chickens was likely. Whether the astroviruses in pigeons were responsible for the diarrhoea remains to be determined.