A variety of microbes cause infections of the myocardium and produce a myocarditis. D. Rhumatic fever 1. Strep antigens may deposit in joints and heart and Ab against Strep damages the heart, particularly valves. Subsequent Strep infections can increase the Ab response and worsen the disease . Still a major health probem in Africa, S. America and Asia.
Initial infection is either cutaneous or respiratory or even inapparent.
Organism has a mutated M protein that makes it resistant ot phagocytosis. Need fast intervention - penicillin and sometimes surgery. Another form is a bacteremia in older people who are already somethat immunosuppressed. Predisposing factors are unclear. Franciscella tularensis .