I was fascinated to discover that there is strong evidence that HIV/Aids was first transmitted from chimpanzees to humans during the First World War, far earlier than I had imagined. According to this excellent radio documentary, it happened in about 1916 in the rain forest of south east Cameroon as a bizarre consequence of the First World War.Cameroon had been a German colony which was conquered by the allies using locally raised African troops as infantry. These soldiers, unlike the officers who got a litre of wine a day in addition to other foodstuffs, were ill-fed and had to hunt their own food – what would now be called bushmeat. This meant shooting with their rifles infected chimpanzees, whom local people had left alone because they are dangerous to hunt with bows and arrows and spears.But the butchering of the chimpanzees appears to have led one soldier from the Congo becoming infected with HIV/Aids and taking it home to the Kinshasa where it became endemic, though it took half a century or more for the virus to spread to the rest of the world.The story is interesting in itself and I had never heard it before. But it is also a sort of parable about the unintended but deadly consequences of the chaos of war.