Bangladeshis have genetic variations that might defend against the disease
Some people in Bangladesh carry genetic alterations that seem to protect against cholera, a study shows. These changes apparently occurred over thousands of years as exposure to the disease exerted a form of natural selection on people in the Ganges River Delta.
Although cholera can cause lethal, dehydrating diarrhea, 60 to 90 percent of people infected with it experience few or no symptoms. That often happens when people have had prior exposure to the microbe that causes the disease, says Glenn Morris, an infectious disease physician at the University of Florida in Gainesville. But a portion of that protection may reflect underlying genetic differences in susceptibility to cholera, he says, and a possible biological mechanism for such safeguards.