This has been a landmark year for Africa. It’s the first year in history, for example, that no wild polio cases have been reported in the continent; a disease that used to strike and often paralyse 350,000 children a year is now almost extinct. Aids infections have halved over the past 15 years. The recent eradication of Ebola in Sierra Leone is only the latest triumph in Africa’s war against the kinds of diseases that have kept so many countries on their knees for so long.

While overseas support has been crucial and highly effective in the struggle, the strongest force pushing back disease in the continent is capitalism; trade still brings in far more money than aid. Indoor smoke, dirty water and hunger still kill more Africans than malaria, so when a villager can afford rudimentary sanitation and healthcare, the effect on disease is profound.

A recent African Union conference set a two-year deadline to turn the whole continent into a free-trade area. This is no mere fantasy: since the beginning of the century, the value of trade between African countries has risen five times over; mobile phones are now as common in Nigeria and South Africa as they are in Britain.

Charities, though, by their nature, don’t tend to spend too much time spreading good news.