Circulation of A2 Subclade of Avipoxvirus in Pigeons of the Andaman and Nicobar Islands, India

Genus Avipoxvirus, an important member of the family Poxviridae, has 12 species which have been recognized by the International Committee on Taxonomy of Viruses (ICTV). Fowlpox virus and pigeonpox virus are two important species that may affect other species of birds, besides chicken and fowl. Hence, accurately identifying species, clades and subclades of Avipoxvirus is vital to design and implement adequate control strategies. The present study was carried out in a pigeon colony showing symptoms of pox. A fragment of viral Pan-genus 4b (P4b) gene was amplified and sequenced. As an equivocal and prototype species, sequence information of fowlpox virus isolated from an infected bird was also generated. The generated sequence information was compared with those of previously reported strains. It was found that both fowlpox and pigeonpox viruses belonged to clade A, and there was circulation of A1 and A2 subclades in chicken and pigeon respectively. From India, one report showed the circulation of A1 and A3 subclades in Indian chickens and pigeons respectively, since the other reports were based on clinical symptoms, histopathological examination and comparison of sequence information with those available without distinct demarcation of clade and subclade of Avipoxvirus. This study describes the findings of the novel A2 subclade of Avipoxvirus and the existence of pigeonpox in the Andaman and Nicobar Islands, India.