Abstract
Rehabilitation and release of seabirds are important tools to minimize anthropogenic impacts on the sustainability of many threatened species. Infectious diseases can be serious threats for the success of such initiatives especially since the knowledge on pathogens affecting those species is usually scarce. Magellanic penguins (Spheniscus magellanicus), whose populations have declined over the last two decades, are considered near threatened by the IUCN Red List.1 Avipoxvirus infection was reported in Argentinian breeding colonies causing local self-limited cutaneous lesions.2 A different avipoxvirus causing cutaneous and diphtheritic lesions in the oesophagus and bronchioli of Magellanic penguins housed in outdoor enclosures in a Rehabilitation Centre located at Florianópolis, Santa Catarina State, Brazil, was reported in 2013 by Niemeyer et al.3 By that time, the authors suspected a spillover effect based on the divergence between the Brazilian penguinpoxvirus (Canarypox clade) and the avipoxvirus (Fowlpox clade) described in the colony. The Rehabilitation Centre kept monitoring and the diagnosis was based on clinical signs, histopathology, and use of the polymerase chain reaction (PCR). Since July 2012, 22 penguins presented clinical signs including cutaneous papules and nodules around eyelids and beaks, depression, and restriction in weight gain. After PCR confirmation of Brazilian penguinpox strain infection, penguins are humanly euthanized and necropsied. The most common gross lesions are severely congested and haemorrhagic lungs, splenomegaly, and cardiomegaly. Histological examination reveals Bollinger inclusion bodies in cutaneous lesions and oesophagus, mild to severe bronchopneumonia, moderate periportal lymphocytic hepatitis, splenic lymphopenia, and lymphocytolysis. Other frequent findings includes enteritis, oesophagitis, dermatitis, and airsacculitis. Cytoplasmic inclusion bodies can be seen within oesophageal epithelial cells and in epithelial cells of the bronchioli. DNA from thirteen samples were amplified whether from skin, lungs and/or oesophagus tissues by PCR using P4b-targeting primers already described in the literature4 for avipoxvirus and using H3L envelope protein gene primers for better classifying the Brazilian strain. The sequences showed different virus strains belonging to the genus Avipoxvirus of the Chordopoxvirinae subfamily, divergent from the penguinpox and avipoxviruses already described in Magellanic penguins in Patagonia, but segregating within the canarypoxvirus clade, those that are commonly related to diphtheritic and respiratory disease in passerines.
Acknowledgements
The authors thank the Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for financial support of this Project and the Fundação do Meio Ambiente do Estado de Santa Catarina (FATMA) for the research support.
* Presenting author
Literature Cited
1. BirdLife International 2012. Spheniscus magellanicus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 15 January 2015.
2. Kane OJ, Uhart MM, Rago V, Pereda AJ, Smith JR, Buren AV, Clark JA, Boersma PD. Avian pox in Magellanic penguins (Spheniscus magellanicus). Journal of Wildlife Diseases. 2012;48:790–794.
3. Niemeyer C, Favero CM, Kolesnikovas CKM, Bhering RCC, Brandão P, Catão-Dias JL. Two different avipoxviruses associated with pox disease in Magellanic penguins (Spheniscus magellanicus) along the Brazilian coast. Avian Pathology. 2013;42:546–551.
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