A view of an IDP camp.

The outbreak in the city of Maiduguri, the epicenter of the fight against the Islamist insurgents, confirms aid groups’ fears that Nigeria’s rainy season could spread disease in camps for the internally displaced that are often already unsanitary.

About 1.8 million have abandoned their homes because of violence or food shortages, many of them live in camps for the displaced throughout northeast Nigeria, particularly in Maiduguri and the surrounding state of Borno.