 Gastrointestinal illness and diarrhea are recognized as a significant cause of morbidity and mortality in the elderly. One study showed that 51 of deaths caused by diarrhea over a 9-year period occurred in individuals over the age of 74 years. Although many infectious diseases are more problematic in the elderly because of a decline in immune function and a higher incidence of pre-existing malnutrition and dehydration, it is still not known what the principal modes of transmission are and which infectious agents are responsible. 