FIG. 6.

Hematoxylin and eosin staining of formalin-fixed splenic tissue. Spleens were removed at different stages of disease. (A) Spleen from an uninfected control with no pathological changes. (B) Spleen from a representative moribund animal sacrificed at day 7 with lymphoid follicle disruption. The inset shows infiltration of fragmented nuclei, some neutrophils, and the absence of megakaryocytes. (C and D) Spleens from survivors sacrificed at early (day 7) (C) and late (day 50) (D) time points showed normal lymphoid follicle architecture. The insets demonstrate the presence of prominent megakaryocytes, as indicated by the arrows. The sections were photographed with a 10× objective, with a 50× objective for the insets.