Coxsackievirus B4 myocarditis in mice: valvular changes in virus-infected and control animals.

Suckling, weanling, and adult HaM/ICR and Swiss-Webster mice were inoculated intraperitoneally with the TC631 and Dowell strains of coxsackievirus B4. Vero cell-inoculated and uninoculated control mice were also studied under code. An intense, necrotizing myopericarditis was produced in suckling mice; it was less severe in weanlings. Myocarditis did not occur when coxsackievirus B4 was inoculated into adult mice. Progressive sclerosis and thickening of all valves in both strains of mice were observed with equal frequency in infected and control mice. There was no evidence that coxsackievirus B4 induced a specific valvular or endocardial lesion.