ABSTRACT
The etiologic agent of Malignant catarrhal fever (MCF) in Africa is a highly cell-associated lymphotropic herpesvirus of the subfamily Gammaherpesvirinae. Epidemiologic evidence from other parts of the world and Africa suggests that domestic sheep may also be reservoirs of a virus causing MCF. MCF virus in cell cultures causes typical herpesviral cytopathic effects characterized by formation of large syncytia which gradually contract and round-up becoming thereby very refractile. Histopathologic lesions provide a consistent basis for the diagnosis of MCF. Microscopic lesions of extensive vasculitis, perivasculitis, and lymphoreticular proliferation in lymphoid organs with mononuclear infiltrations in kidney, liver, adrenals, central nervous system, etc., are pathognomonic for a diagnosis of MCF. The stocking of cattle ranches with alcelaphine antelope, wild sheep or goats should be discouraged, or should require a negative MCF serologic test, preferably by the serum-virus neutralization method, for any wild ruminants destined for such a facility.
