Adult heart disease due to the Coxsackie virus group B.

Myocarditis, until lately out of favour, is again becoming an acceptable diagnosis. The myocardium can be attacked by many organisms such as bacteria, viruses, fungi, rickettsiae, spirochaetes, and parasites. Viruses are of special importance, and acute or chronic myocarditis has been occasionally described in such viral infections as measles, mumps, poliomyelitis, infectious mononucleosis, psittacosis, rabies, varicella, variola, lymphocytic choriomeningitis, influenza, Coxsackie infections, infective hepatitis, yellow fever, and epidemic hemorrhagic fever (Woodward et al., 1960). The Coxsackie group B viruses are now increasingly recognized as a relatively frequent cause of myocarditis with or without pericarditis. The Coxsackie virus was named by Dalldorf (1949), who isolated it in 1948 from the stools of two paralysed children who lived in the small town of Coxsackie, near New York. Today the Coxsackie genus of viruses comprises Group A and Group B, containing 24 and 6 types, respectively. These groups have similar physical and biological properties, but differ in their clinical effects in man and animals. The two groups can be separated by their different effects in susceptible animals, especially the neonatal suckling mouse. Group A viruses cause a diffuse skeletal myositis and flaccid paralysis, often with herniation of the abdominal wall. Group B viruses cause a patchy myocarditis, focal skeletal necrosis, tremors, and spastic paralysis. These features are often associated with encephalomyelitis, hepatitis, and pancreatitis. The essential difference is the production of myocardial lesions by the Group B viruses. Coxsackie viruses are world wide, and are frequent causes of upper respiratory tract infection, gastroenteritis, and other clinical syndromes. Curnen,