As an academic and women’s health activist in the early 1990s, Sheila Tlou was reprimanded by government ministers in the Botswana government for raising the spectre of Aids.

“Don’t talk about that or you’ll scare us,” she recalls them telling her. By the time she became health minister, the situation had reversed. Botswana may be one of the smallest, richest and least corrupt countries in Africa. But it is also among the most severely burdened with Aids, and has launched one of the most comprehensive responses.