 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 Lew et al. 1991. In a review of sensitive populations, Gerba et al. 1996 reported case fatality rates for specific enteric pathogens 10 to 100 times higher in this group compared to the general population. 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. 