Diseases are often disastrous, but they tend to come in for a while and then leave again. We've heard about everything from Mad Cow Disease to ebola on TV for about three weeks and then it goes away for a few years.
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One disease that hasn't done that is the Human Immunodeficiency Virus or HIV. The spread of HIV has long filled television screens because it is just so confusing as to what it actually does and how it started.
Everything started in Kinshasha, the capital of what is now known as the Democratic Republic of Congo, according to Futurism. In the 1920s, it was better known as the colony of Leopoldville.
The area was popular with young men who came to make a fortune - which meant that it had a rotating cast of characters and sex workers. Infections spread and HIV found a way to grow into the problem that it still is today.
There were two types of HIV infection - HIV-1 group M, which originated here and accounts for 90% of all HIV and HIV-1 group O, which developed nearby but never seemed to spread.
"Ecological rather than evolutionary factors drove its rapid spread," says Nuno Faria at the University of Oxford in the UK, in an interview with the BBC.
Faria and his colleagues built a family tree of HIV by looking at the genomes collected from 800 people living with HIV in central Africa.
Ultimately, Faria determined that all of the genes had a common ancestor from no more than 100 years ago - meaning that it all began around 1920. All of the information can be traced back to Kinshasa, or the capital of the Democratic Republic of Congo.
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All in all, this study helps us to localize the origin of the diseases and find out how and why it started to spread when other diseases were cut off. It might even help us find a cure or reduce the spread of infection.