Comparison of Three Agents of Acute Infectious Nonbacterial Gastroenteritis by Cross-Challenge in Volunteers

Abstract

Two family outbreaks of acute infectious nonbacterial gastroenteritis occurred in Honolulu, Hawaii, and Montgomery County, Maryland. The disease was reproduced in volunteers with bacteria-free stool filtrates derived from each outbreak. These filtrates containing the Hawaii and Montgomery County agents, as well as filtrates containing the previously described Norwalk agent, produced clinically similar illness in volunteers. Therefore, volunteers were cross-challenged to determine whether illness was produced by antigenically related or unrelated agents. It was suggested that the Norwalk and Hawaii agents were, antigenically dissimilar, since disease produced by either agent failed to confer immunity to subsequent disease caused by the other. In contrast, similar studies suggested antigenic relatedness between the Norwalk and Montgomery County agents, since Norwalk-induced disease seemed to confer immunity to later challenge with the Montgomery County agent.