Travelers' diarrhea among United States Marines in South Korea.

A battalion of United States Marines traveling to South Korea in the spring of 1976 was studied to determine the incidence and etiology of gastroenteritis. During the three weeks they visited South Korea, 21% of 694 marines developed diarrhea. Stool and serum specimens collected before, during, and after their stay were examined for evidence of infection with Salmonella, Shigella, and Vibrio species, enterotoxigenic and invasive Escherichia coli, reovirus-like agent (RVLA), and intestinal ova and parasites. Infections with these agents were uncommon; 91% of 44 closely studied cases of gastorenteritis were unexplained. Five per cent of 169 marines had serologic evidence of recent infection with RVLA, and 3% of 273 marines had serologic evidence of infection with heat-labile enterotoxin producing E. coli over an eight-week period. However, infections with these agents were not associated with most cases of diarrhea in South Korea. It is concluded that infectious agents previously thought responsible for travelers' diarrhea were not responsible for gastroenteritis among United States Marines arriving in a temperate climate.