Vibrio cholerae is a bacterium that causes cholera, a severe diarrheal disease. It is typically found in contaminated water or food, particularly in areas with poor sanitation. The bacterium produces a toxin that affects the intestines, leading to rapid fluid loss and dehydration. Cholera can spread quickly in crowded conditions, especially after natural disasters or in refugee camps. Symptoms include watery diarrhea, vomiting, and cramps. If untreated, cholera can be life-threatening, but it is preventable and treatable with proper hydration and antibiotics. Public health measures are essential to control outbreaks.