Although it is well known that the same host species can be infected with different strains of APV, the genetic diversity of strains in different hosts has been poorly studied. Currently, a total of nine APV strains have been identified in house sparrows globally, seven of which are in the canarypox clade and two in fowlpox. Three strains have been found that infect house sparrows in Spain, CNPV-PD1 to CNPV-PD3, although CNPV-PD3, highly similar to CNPV-PD2, has been identified only from a museum skin collected from central Spain in 1911 . The genotype CNPV-PD1 has been detected infecting other species in the Iberian Peninsula and North Africa (Lisbon and Morocco) . Although the subclade B2 consists of isolates from Sturnidae (starlings and mynahs), to date no APV has been detected in Sturnidae in Spain. The genotype CNPV-PD2 has been found in numerous wild bird species around the world. In Spain, this genotype was found in Passeriformes sampled in 2007 belonging to the genera Cyanistes, Periparus and Sylvia and in two museum voucher specimens dated from 1911 from the genera Loxia and Passer . All samples were negative for papillomavirus but to date this viral infection has never been diagnosed in house sparrows.