History of HIV: Africa, chimpanzees, hunters, railways...

At the beginning of the last century, HIV started a pandemic that infected more than 75 million people worldwide.

The virus first affected monkeys, and humans became infected when they hunted and ate their meat, an international team of scientists announced.

Genetic analysis of a thousand virus samples revealed that HIV first appeared in 1920 in Kinshasa, then the capital of the Belgian Congo.

Then it spread through Central Africa via the colonial railway, writes the BBC. Analyzing the origin of HIV, scientists realized that it evolved from a virus that first affected monkeys. Humans got the virus when they hunted chimpanzees and ate their meat.

Infected hunters arrived in Kinshasa, then called Leopoldville, and spread the disease to the local population.

As prostitution flourished in the city, the virus infected prostitutes and their increasingly numerous clientele.

Doctor Nuno Faria from Oxford and one of the members of the team that discovered the origin of HIV believes that the construction of the railway contributed to its spread.

"Kinshasa at that time was one of the largest cities in Central Africa, at the same time well connected by traffic to other parts of the Congo. Data from the colonial archives show that at the end of the 40s of the last century, more than a million people passed through this city annually ", says Faria.

Then he added, "Genetics reveal that HIV spread rapidly through Congo, a country the size of Western Europe.

When the Congo gained independence in 1960, workers from Haiti arrived. They 'took' the virus home from where it spread to the US, Europe and the rest of the world."