Through the most comprehensive genetic analysis so far, scientists believe they have traced the origins of the AIDS pandemic to Kinshasa — the capital of what is now the Democratic Republic of Congo.
The human immunodeficiency virus (HIV) is thought to have originated in southern Cameroon where it probably crossed to humans handling chimpanzee bush meat. However, HIV remained regionalised until it entered Kinshasa in the 1920s.
At that time, Kinshasa was the fastest growing city in central Africa: its transport links — which included a modern railway system — allowed large numbers of male migrant workers to converge upon the bustling trading post. This skewed the gender balance, which in turn led to a roaring sex trade. It’s thought the virus was further spread by doctors injecting patients with unsterilised needles.
“It seems a combination of factors in Kinshasa in the early 20th century created a perfect storm for the emergence of HIV, leading to a generalised epidemic with unstoppable momentum that unrolled across sub-Saharan Africa,” said Professor Oliver Pybus, lead author of the study published in the journal Science.
The virus stayed confined to the Congo until the 1960s, when it spread to America and around the world. Since the beginning of the epidemic 75 million people have been infected with HIV; while up to 40 million have been killed by the virus.