HIV/AIDS origin traced to Kinshasa, DR Congo, in 1920s; spread by trains

The origin of the HIV/AIDS pandemic has been traced to Kinshasa - now the capital of the Democratic Republic of Congo - around 100 years ago. Population growth, the sex trade and railways allowed the disease to spread, according to researchers from the journal Science. They used archived samples of the HIV virus’s genetic code to trace its source and found the evidence pointed to early 1920s Kinshasa - then known as Leopoldville - where unsterilised needles used in health clinics helped spread the disease. The virus was escalated by men - who outnumbered women by two to one - which lead to the growth of a massive sex trade.

It was already known that HIV in humans arose by cross species transmission from chimpanzees in that region of Africa, but this study maps in great detail the spread of the virus from Kinshasa, it was fascinating to read.

Dr Andrew Freedman, a reader in infectious diseases at Cardiff University

The disease was spread to neighbouring regions by the Belgian-backed railway. “Data from colonial archives tells us that by the end of 1940s over one million people were travelling through Kinshasa on the railways each year,” Nuno Faria of Oxford University’s Department of Zoology, one of the authors of the paper, said. Over the following decades it spread throughout the world, but was only identified in 1981. As part of the research, scientists from the University of Oxford and the University of Leuven in Belgium tried to reconstruct HIV’s “family tree” to trace its origin. HIV is a mutated version of a chimpanzee virus which was probably passed to people through contact with infected blood while handling meat.

We think it is likely that social changes around independence in 1960 saw the virus ‘break out’ from small groups of infected people to infect the wider population and eventually the world.

Nuno Faria

Health HIV