Results of an ongoing project on changes in organs of slaughtered animals alerted us of the likely underreporting of ovine pulmonary adenocarcinoma (OPA) in Switzerland. Of the 364 lungs examined during the last two years, 142 were histologically diagnosed with OPA. Of these, 25% also showed lesions suggestive of Maedi-Visna (MV) or Caprine Arthritis Encephalitis (CAE) virus infection, indicating that co-morbidities are common. Confirmation of the diseases requires detection of the causative viruses, optimally both at molecular and in situ level. For the former, qPCR protocols have recently been established by the co-applicant at the IVI in Berne. The latter will be addressed in the proposed study which will establish immunohistology protocols for the detection of Jaagsiekte-Retrovirus (JSRV), MVV and CAEV in histological specimens. The new techniques will be used to obtain a realistic picture of the prevalence of OPA, MV and CAE, and to investigate viral cell tropism and pathogenic processes in co-morbidities, including their potential interdependency.
