Nigeria, Nov. 23 -- Hannatu Sabiu held her three-year-old grandson, Muhammad Sani, close to her chest, his limp body resting against her. The boy's half-open eyes darted weakly around the dimly lit consultation room of a health post in Ringim, a village in Ganjuwa Local Government Area (LGA) of Bauchi State.

At intervals, Muhammad would let out a shriek, and his grandmother would rock him gently to stop him from crying, while she explained his condition to a health worker attending to them.

The child had been sick for a while, withdrawing from the playground and clutching his belly while he cried on his grandmother's lap. He was administered paracetamol at home for days, but his condition only worsened.

"The fever was on and off," Mrs ...