When the worst of her infection was over, Tyesha found herself wondering about the cause of her infection. She knew that cholera was a big problem in many developing countries, but largely unknown in the United States. She wanted to understand the difference. Sure, she had some fresh shellfish that last night in Haiti, but she ate raw sushi all the time with her friends dining out at home. Tyesha, with her public health interests, decided to find out all she could about the incidence of cholera, and to go back there and help when she finished her schooling. For Tyesha, her bout with cholera was a frightening and disgusting experience, but one that was relatively easily handled. Why is cholera such a devastating illness in much of the developing world