Twelve messages from enteric infections for science and society.

Diarrheal diseases hold profound messages as well as opportunities that range from public health to basic science. From the spread of cholera around the world, we are reminded of the global impact of tropical diseases, that disease may provide a litmus test for poverty to drive a sanitary revolution, that disease spread may be worsened by political denial, and that many ecologic and epidemiologic secrets such as interepidemic microbial niches remain poorly understood. Diarrheal diseases other than cholera teach us that heavy disease burdens do not control population growth but are associated with population overgrowth (i.e., improved health is key to controlling the population explosion), the societal impact of diarrhea morbidity may exceed even that of its mortality, that new agents continue to emerge, and that nosocomial diarrhea is an underrecognized threat in our hospitals. Finally, from the laboratory of the developing world also come messages for basic science. Microbial toxins continue to elucidate a new understanding of cell signaling, and mechanisms once thought to be clear (such as that of cholera toxin) now appear much more complex. Traditional remedies hold new pharmacologic secrets, e.g., such as gingko extracts that inhibit platelet-activating factor. Finally, from basic physiology can come widely applicable practical solutions such as oral rehydration therapy and simplified diagnostics for inflammatory diarrhea. Health problems such as diarrheal diseases that plague the disadvantaged are linked to population overgrowth and provide some of the greatest challenges to modern science and the industrialized world.