Nigeria, Feb. 15 -- Kaltumi Mustapha was waiting her turn to fetch water at a borehole on a sunny afternoon in 2019 when a neighbour came running and urged her to return home immediately.

Panic gripped Mrs Mustapha as she abandoned her bucket and hurried back to her shelter. She found her four-year-old daughter, Aisha, convulsing on the floor, her body jerking violently, teeth clenched, and breath weakening.

"I was so scared that this might be worse than I had seen before. I wanted to hold her, but her bones were rigid, and her body was stiff. I had to carry her with all my might and rushed her to the hospital in town, Waru," Mrs Mustapha recalled.

Sadly, despite desperate efforts to save her, Aisha did not survive this episode. Her de...