Papillomavirus-associated Cutaneous Papillomas in a Population of Wild Spotted Hyenas (Crocuta crocuta)

Beginning in 1997 Michigan State University Mara Hyena Project investigators observed waxing and waning progression of oral and genital masses during long-term behavioral observations of a population of wild spotted hyenas (Crocuta crocuta) from the Masai Mara Game Reserve, Kenya. From 1999-2000, we darted adult spotted hyenas to obtain routine physiologic and hematologic data and collected small, raised, lobulated, pigmented masses from the oral or genital areas of eight animals. Microscopically, masses consisted of variably thickened epidermis with thick elongate rete pegs, prominent stratum spinosum, and few koilocytes, consistent with papillomavirus-induced lesions. Immunohistochemistry on formalin-fixed, paraffin-embedded papilloma tissue revealed positive intranuclear labeling for papillomavirus antigen in the superficial stratum granulosum and in sloughing keratin layers of multiple samples. Polymerase chain reaction on DNA extracts from tumor tissue amplified a papillomavirus-specific 418 base pair amplicon in the E1 ORF. Basic Local Alignment Search Tool analysis of the sequenced amplicon suggests a novel hyaenid papillomavirus. Confirmatory complete genomic sequencing was performed later by the Rega Institute in Belgium. To our knowledge, this is the first report of a papillomavirus in a Hyaenidae species. Spotted hyena social behavior might facilitate oral-genital transmission of papillomavirus in this population.