Identification and characterisation of Gamma-herpesviruses in zoo artiodactyla

Background: Viruses within the γ-herpesviruses subfamily include the causative agents of Malignant Catarrhal Fever (MCF) in several species of the order Artiodactyla. MCF is a usually fatal lymphoproliferative disease affecting non-adapted host species. In adapted host species these viruses become latent and recrudesce and transmit during times of stress or immunosuppression. The undetected presence of MCF-causing viruses (MCFVs) is a risk to non-adapted hosts, especially within non-sympatric zoological collections. This study investigated the presence of MCFVs in six different zoological collections in the UK, to evaluate the presence of subclinical/latent MCFVs in carrier animals. Methods: One-hundred and thirty eight samples belonging to 54 different species of Artiodactyla were tested by Consensus Pan-herpes PCR. The positive samples were sequenced and subjected to phylogenetic analyses to understand their own evolutionary relationships and those with their hosts. Results: Twenty-five samples from 18 different species tested positive. All viruses but one clustered in the γ-herpesvirus family and within the Macavirus as well as the non-Macavirus groups (caprinae and alcelaphinae/hippotraginae clusters, respectively). A strong association between virus and host species was evident in the Macavirus group and clustering within the caprinae group indicated potential pathogenicity. Conclusion: This study shows the presence of pathogenic and non-pathogenic MCFVs, as well as other γ-herpesviruses, in Artiodactyla species of conservation importance and allowed the identification of new herpesviruses in some non-adapted species.