VIRAL-INFECTIONS OF THE GASTROINTESTINAL-TRACT

In terms of worldwide morbidity and mortality, viral enteritis is one of the most ubiquitous and important infections of the human gastroint estinal tract. Knowledge of the epidemiology and clinical spectrum of viral gastroenteritis is growing rapidly. This is particularly because of the availability of better reagents to detect infections due to No rwalk viruses and astroviruses. Computer-enhanced cryoelectron microsc opy has been used to reveal the interrelationships of capsid units in Norwalk and rotavirus. Although no major breakthroughs were reported f or rotavirus vaccines, several ''experiments of nature'' support the c oncept that protective immunity without disease occurs in nature. Noni mmunologic host defense mechanisms against viral enteritis such as muc ins are also being examined in hopes of finding new treatments or prop hylactic agents.