The histopathology of enterovirus infections of new-born mice

For 32 years we have provided a routine histopathological service on animals for the Regional Virus Laboratory, Ruchill Hospital, Glasgow. This article concerns mainly experimental coxsackievirus A, coxsackievirus B and echovirus infections in new-born mice. In addition to previously reported findings, we have sometimes observed degenerative and inflammatory changes in neurons related to the Gasserian, posterior root or autonomic ganglia. Not all deposits of brown fat are simultaneously the seat of inflammatory changes; rarely, inflammation of brown fat spills over into the adjacent yellow adipose or connective tissues. Brown fat may occasionally show hyperplasia. Ballooning of the tips of small intestinal villi with interstitial oedema and/or necrosis of villous tips may indicate enanthemata associated with coxsackievirus A2,5,7,8, 10,23 as well as with coxsackievirus B1 and B4 infections. Similar appearances were seldom seen with echovirus infections. Focal bone-marrow necrosis and necrosis of cartilage were associated with one coxsackievirus Aio infection, and osteitis with one coxsackievirus B3 infection. The implications of these uncommon observations for human pathology remain to be determined.