Pathology of spontaneous and experimental infections by Goose haemorrhagic polyomavirus

Abstract

Haemorrhagic nephritis enteritis of geese (HNEG) is a fatal disease of geese aged from 3 to 12 weeks. The causative virus, Goose haemorrhagic polyomavirus (GHPV), is a member of the Polyomaviridae family We examined goslings either spontaneously or experimentally infected with GHPV. Tissues were sampled for histology, GHPV DNA detection and electron microscopy. Clinical signs and gross lesions observed in experimentally infected goslings were largely consistent with those noticed in field cases. Histological examination showed that, in the acute phase of HNEG, GHPV replicates in almost all the tissues with a particular tropism for endothelial and lymphoid cells. Haemorrhagic foci were widespread in many tissues, including brain. Ultrastructural features were largely consistent with other polyomavirus infections, with accumulation of virions in the nucleus. Non-typical, double-membraned organelles were observed in the cytoplasm. GHPV DNA distribution was widespread in tissues of infected birds, from day 5 post-infection. GHPV therefore induces a systemic disease in its host, leading to severe vascular dysfunction and immunosuppressive B-cell depletion.

Acknowledgements

We gratefully thank Pr. John H. Barnes (College of Veterinary Medicine, NCSU, Raleigh, US), as our colleagues Drs Christelle Camus-Bouclainville, Frédérique Messud and Stéphane Bertagnoli for their helpful suggestions and careful reading of the manuscript. We recognize the contribution of Isabelle Fourquaux and Jean-Luc Duteyrat to electron microscopy examinations. This work was supported by Régions Aquitaine and Midi-Pyrénées, CIFOG (Comité Interprofessionnel des Palmipèdes à Foie Gras) and OFIVAL (Office Interprofessionnel des Viandes, de l'Elevage et de l'Aviculture).