Peroral Infection with Group B Coxsackievims in the Adult Mouse: Protective Functions of the Gut

A previous study has shown that newborn mice are as susceptible to group B coxsackieviruses administered by the peroral route as they are to these viruses given by the intraperitoneal route. The adult mouse is also susceptible to infection with these viruses by both routes. In the older host, however, the intestinal tract provides effective protection against peroral infection. This protection consists of at least two separate components: (1) a barrier effect that prevents the passage of virus from the intestinal lumen through the mucosal side of the gut into the circulation, and (2) a clearance mechanism that eliminates virus from the enteric tract after infection has occurred. These mechanisms may help to explain the marked difference between the susceptibility of the human newborn and that of the human adult to these viruses.