THE AGE FACTOR IN EXPERIMENTAL COXSACKIE B-3 INFECTION

A detailed study of the influence of the age factor upon the susceptibility of the white mouse to experimental infection with a standard strain of Coxsackie B-3 virus has been undertaken. A fairly accurate assessment of the susceptibility of the brain, heart, and brown fat tissues has been achieved by examining sufficiently large groups of animals inoculated at ages varying from 4 days to 182 days by histological and virological procedures.The contrasting patterns of changing susceptibility in the brain and heart were quite remarkable. Brain lesions were not found in mice inoculated after 12 days of age but heart lesions were severest in animals inoculated between 12 and 23 days of age. In both heart and brown fat tissue lesions could be found in adult animals infected with Coxsackie B-3 virus. Attention is drawn to the fact that the pathological response in the brown fat tissue is different in sucklings, weanlings, and adult mice.