Two different avipoxviruses associated with pox disease in Magellanic penguins (Spheniscus magellanicus) along the Brazilian coast.

ABSTRACT

A novel avipoxvirus caused diphtheritic lesions in the oesophagus of five and in the bronchioli of four Magellanic penguins (Spheniscus magellanicus) and also cutaneous lesions in eight Magellanic penguins housed in outdoor enclosures in a Rehabilitation Centre at Florianópolis, Santa Catarina State, Brazil. At the same time, another avipoxvirus strain caused cutaneous lesions in three Magellanic penguins at a geographically distinct Rehabilitation Centre localized at Vila Velha, Espírito Santo State, Brazil. Diagnosis was based on clinical signs, histopathology and use of the polymerase chain reaction (PCR). Clinical signs in the penguins included cutaneous papules and nodules around eyelids and beaks, depression and restriction in weight gain. The most common gross lesions were severely congested and haemorrhagic lungs, splenomegaly and cardiomegaly. Histological examination revealed Bollinger inclusion bodies in cutaneous lesions, mild to severe bronchopneumonia, moderate periportal lymphocytic hepatitis, splenic lymphopenia and lymphocytolysis. Other frequent findings included necrotizing splenitis, enteritis, oesophagitis, dermatitis and airsacculitis. Cytoplasmic inclusion bodies were seen within oesophageal epithelial cells in five birds and in epithelial cells of the bronchioli in four penguins. DNA from all samples was amplified from skin tissue by PCR using P4b-targeting primers already described in the literature for avipoxvirus. The sequences showed two different virus strains belonging to the genus Avipoxvirus of the Chordopoxvirinae subfamily, one being divergent from the penguinpox and avipoxviruses already described in Magellanic penguins in Patagonia, but segregating within a clade of canarypox-like viruses implicated in diphtheritic and respiratory disease.