Rocky mountain spotted fever
Infection due to Rickettsia rickettsii affects blood vessels throughout the body. The myocardium, as
in this case, shows a mononuclear cell infiltration. Grossly, petechial hemorrhages are usually present.
In this photo RBCs have extravasated into the interstitium and myocyte dropout is apparent.
1 minute clinical correlation
From the slide collection of the late Dr. Charles Kuhn