An outbreak of cholera in West Africa has killed at least 177 people and sickened more than 9,000 in Guinea-Bissau within the past month.

In an attempt to control the outbreak, the government has banned the sale of water at markets. Cholera is an intestinal infection usually spread through contaminated water or food. It causes life-threatening dehydration if not treated.

Health officials say this year's rainy season in Guinea-Bissau has created favorable conditions for the spread of the disease. Flooded latrines can contaminate nearby well water.

The World Health Organization says Burkina Faso, Guinea, Liberia, Mali, Mauritania, Niger and Senegal also have seen a rise in cholera cases.