A comparative pathogenesis of two Mareks disease virus isolates

The pathogenesis of the JM and GA isolates of Marek's disease virus (MDV) infection was compared by studying the sequential tissue distribution of MDV associated antigens with gross and microscopic lesions in infected chickens. With both MDV isolates the initial sites of viral replication were the lymphoid organs, skin, and featers. Both the GA and JM isolates were viscerotropic as demonstrated by the presence of MDV antigens with gross and microscopic changes occurring in several visceral organs. The JM isolate was more neurotropic and had a greater affinity for the gonads than the GA isolates as evidenced by an early detection of MDV antigens and severe pathology in the peripheral nerves and gonads.