Historically the diarrheal diseases have been a plague of armies, a major hazard to the life and health of infants and a common cause of illness among institutional inmates. The expanded sphere of our nation's activity now includes areas where these disorders still remain in their historical place of importance. Thus American physicians and health authorities face the acute diarrheal diseases not as a fast disappearing group of disorders but as a major current medical problem.
During the past six years the National Institute of Health has maintained a field laboratory for the investigation of these diseases. Studies have been conducted in four widely differing areas selected as representative of those with very high, high, medium and low mortality from diarrheal diseases (Puerto Rico, New Mexico, Georgia and New York City). As a part of this work we studied 1,499 cases occurring in the general population, obtained satisfactory clinical data