For European colonizers, Africa’s forests held the promise of untold riches – ivory, rubber and minerals. But unknown to the fortune seekers, those forests also held a virus that would claim over 30 million lives since the global spread of the HIV epidemic.
Craig Timberg and Dr. Daniel Halperin say European rule in Africa led to a number of social and economic changes that facilitated the spread of the virus. They're the authors of a new book on the origins of rearch of virus called
?Halperin is a medical anthropologist and epidemiologist at the University of North Carolina and until recently the Harvard School of Public Health. He also worked in AIDS-prevention programs in Africa under the administration of President George W. Bush.
Timberg and Halperin write that genetic researchers have traced the origins of human immune deficiency virus (HIV) to the jungles of southeastern Cameroon.
Timberg, who is the former Johannesburg bureau chief for , said researchers compared the most prevalent and deadliest form of HIV to SIV, simian immune-deficiency virus, found in local chimpanzees.
He described their efforts at a recent lecture at the Foreign Policy Research Institute in Philadelphia.
"They set up collection stations across the range of where these chimps were in southern Cameroon and collected their waste," he explained.
"Chimp feces carried remnants of the virus, and they could compare the particular chimpanzee viruses to the dominant form of HIV," he said. "What they found [are areas where the viruses] are close at the genetic level, particularly in the southeastern corner [of Cameroon]. You almost can’t tell the chimp virus and dominant human virus from one another, they are so almost perfectly identical."
Timberg said even today, not many people live in southeastern Cameroon, an area with its dense jungles that's difficult to access. Through much of history, he said, there weren’t many opportunities for humans and chimps to interact.
That changed with the arrival of railways, roads and steamships. They carried goods from trading stations along Africa’s most powerful river, the Congo, and its tributaries reaching into the rainforests.
"African men and women became laborers, carrying goods back and forth from the jungles to pay colonial taxes," said Timberg. "Others were forced to work as porters. Local communities then, as today, killed chimps to sell as “bush meat.”
Scientists say it’s likely the virus made the leap to humans when a hunter cut himself while handling an infected animal. New transportation routes meant the hunter and the virus were no longer confined to a remote and sparsely populated area, where both were likely to eventually die.
?"There is an old porter path that’s now a highway... a dirt road today, that came within about a mile of where the scientists collected the chimp waste that’s had the virus that’s virtually identical to the version of HIV that’s killed almost everybody who’s died of AIDS," explained Timberg,
Other elements were added to the “tinderbox” that would make a once-localized illness combust.
Changing customs made it easier to spread the virus. The colonial powers discouraged polygamy, which medical anthropologists say tended to create what they call a “closed circuit” that tended to limit sex to married partners. By contrast, younger generations under the influence of Christianity may have married a single partner, but also had ongoing relationships with others.
Younger men also were less likely to participate in initiation rituals including circumcision, a widespread tradition in much of Africa that scientists have found largely protects men from HIV. The practice removes the foreskin of the penis, a vulnerable point of entry for the virus.
A growing urban population led to the spread of sexually transmitted diseases, or STDs, in densely populated Leopoldville, now Kinshasa.
"The historical record is clear," said Timberg. "You have an explosion of STDs, things that were not a major problem before the Europeans arrived. Suddenly they are at epidemic levels."
"The Belgian colonialists are actually complaining to each other, asking why are birth rates plummeting, how [they can] make a colonial economic machine without labor for from high birth rates," he said. "They thought it had to do with polygamy. But it had to do with STDs – the women were sick. What we now know is that HIV was one of the STDs moving about in that part of the world at a low level but in a persistent way for decades."