Study: A perfect storm of factors that came together in Africa early in the 20th century led to the spread of HIV/AIDS in the human population and eventually a full-blown pandemic infecting more than 75 million people worldwide

A genetic analysis of thousands of individual viruses has confirmed beyond reasonable doubt that HIV/AIDS first emerged in Kinshasa in about 1920 from where it spread via the railway network to other parts of central Africa. Scientists believe the findings have finally nailed the origin of the HIV/AIDS pandemic to a single source, Kinshasa, which had become the biggest urban center in Central Africa and a bustling focus for trade, including a market in wild “bush meat” captured from the nearby forests. The study, based on analysing the subtle genetic differences between various subtypes of HIV, found the human virus had evolved from a simian virus infecting chimps which were hunted for food by people who had probably carried HIV with them into Kinshasa. Rapid social changes, such as an increase in commercial sex workers and the re-use of dirty syringes, aided the transmission of the virus which was also carried to distant parts of the Congo by the millions of passengers who used the newly-built railway network, the scientists said. Kinshasa at that time was growing fast, it was the biggest city in central Africa and was very well connected to the rest of the Congo. Data from historical archives shows that by the end of the 1940s over one million people were travelling through Kinshasa on the railways each year. Further social changes brought about as a result of independence in 1960 helped the virus to “break out” from small groups of infected people into the wider population, including immigrant workers from Haiti who then carried their infection back home from where it would eventually be transmitted to visitors from the United States. By the 1960s, transport systems such as the railways that enabled the virus to spread vast distances were less active, but by that time the seeds of the pandemic were already sown across Africa and beyond. Ironically, it was a combination of European technology and African backwardness that led to HIV/AIDS becoming a generalised epidemic with unstoppable momentum that unrolled across sub-Saharan Africa.