Scientists Say Kinshasha is Birthplace of HIV Pandemic
A new study in Science magazine traces the origins of the current HIV pandemic to 1920s Kinshasha, in what is now the Democratic Republic of Congo.
"Until now, most studies have taken a piecemeal approach to HIV's genetic history, looking at particular HIV genomes in particular locations," lead author Oliver Prybus of Oxford University said in a statement. "For the first time, we have analyzed all the available evidence using the latest phylogeographic techniques, which enable us to statistically estimate where a virus comes from. This means we can say with a high degree of certainty where and when the HIV pandemic originated."
Kinshasa was a regional boom town, reports the Washington Post. With an abundance of trade and work opportunities, it drew large numbers of male laborers. The gender balance heavily favored men over women, which gave way to a robust sex trade. It was a necessary component for the pandemic to spread, considering this little-reported aspect of HIV: It's not that infectious.
To spread HIV requires a large population with a sexual culture in which people often have more than one partner, propelling the virus through networks. Kinshasha had this 'perfect storm.' And by the 1940s, according to the Guardian, Kinshasa's railways transported more than 1 million people per year.
"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 generalized epidemic with unstoppable momentum that unrolled across sub-Saharan Africa," said Pybus. "Our research suggests that following the original animal to human transmission of the virus there was only a small 'window' during the Belgian colonial era for this particular strain of HIV to emerge and spread into a pandemic."
Rueters reported that a key factor was also the DRC's transport networks, particularly its railways, which made Kinshasa one of the best-connected of all central African cities.
"Data from colonial archives tells us that by the end of 1940s over one million people were traveling through Kinshasa on the railways each year," said Nuno Faria of Oxford University, who also worked on the team.
He said the genetic data showed that HIV rapidly spread across the DRC -- a country the size of Western Europe -- traveling with people along railways and waterways to reach Mbuji-Mayi and Lubumbashi in the extreme south and Kisangani in the far north between the end of the 1930s and early 1950s.
The team's findings also suggest that along with transport, social changes such as the changing behavior of sex workers and public health initiatives against other diseases that led to the unsafe use of needles may have contributed to turning HIV into a full-blown epidemic.
"We think it is likely that the social changes around the independence in 1960 saw the virus break out from small groups of infected people to infect the wider population and eventually the world," said Faria.