Discussion of Dr. Paul C. Beaver's Paper

Abstract

Dr. Beaver is to be congratulated for calling attention to the frequency and importance of visceral larva migrans, for demonstrating the most important etiological agent and the consequent epidemiology of the disease, and for subsequent work in his laboratory which has made it possible, for the first time, correctly to identify larval nematodes found in tissues. When parasites invade so-called “foreign” hosts to which they are not fully adapted, they frequently lose their way; the guide posts, whatever they may be, that enable a parasite to migrate to its proper destination in a “normal” host are absent, causing the parasites to become stranded along the way, or to end up in abnormal situations. Such misplaced parasites frequently cause more disturbance and embarrassment than they do in their normal hosts. There are examples of this phenomenon in all the major groups of parasites.