HIV: A History

“Tinderbox” offers surprising revelations about HIV, AIDS.

HIV: A History

The war on AIDS is now three decades old, but it’s been years since the media paid close attention to developments in the fight against HIV. So it’s perhaps not surprising that little of the latest research on the history of HIV has penetrated the public consciousness. Did you know, for instance, that geneticists have identified 1908 as the (most likely) year in which HIV made the leap from chimpanzees to humans? Or that HIV made that leap in a remote equatorial forest in southeastern Cameroon, before making its way south to Leopoldville (now Kinshasa), and then radiating out to other parts of the world?

These are just a few of the discoveries revealed in “Tinderbox: How the West Sparked the AIDS Epidemic and How the World Can Finally Overcome It” (Penguin Press), by the Washington Post’s Craig Timberg and epidemiologist/medical anthropologist Daniel Halperin. Timberg and Halperin advance the argument that Western colonial powers unwittingly sparked the AIDS epidemic by sending people into remote parts of sub-Saharan Africa, where chimps had carried the simian version of the virus for hundreds of years without spreading it to humans. The co-authors also highlight the critical role of male circumcision in controlling the spread of HIV, and why Western attempts to stem the epidemic (through condom distribution and abstinence campaigns) been less effective than many homegrown African initiatives.

In the following Failure Interview, Timberg discusses the history of HIV, as well as the successes and failures in the longstanding fight against AIDS, and what worries him most about the future.

How long has HIV been around?
The strain of HIV that has killed ninety-nine percent of everyone who has died of AIDS [HIV-1 group M] jumped from the chimpanzee population to the human population about a hundred years ago.

How do we know that HIV is as old as it is?
Viruses have their stories coded in their genetic structures, and if you can get two pieces of virus and see the ways in which they are similar and the ways in which they are different, you can make reasonable assumptions about how many waves of mutation they would have to go through to be as different as they are.

The scientists who have done the best research on this worked from a well-known piece of HIV that came from 1959 in what is now Kinshasa. They then found a second piece of virus in a blood sample from 1960 and what they discovered is that they were remarkably different. When they figured out the number of mutations it would have had to go through to find what they call a common ancestor, they recognized it had to have happened between 1884 and 1924. 

How did the virus move from chimpanzee to man?
The dominant theory is that somebody caught a chimpanzee that was infected with the simian version of HIV, and in the process of butchering it cut his hand, whereby blood from the chimp flowed into the blood of the human. The chimpanzee equivalent of HIV that was found in the area identified as the birthplace of the virus is virtually indistinguishable from the strain that kills most humans. 

What got the epidemic moving among humans?
There were several important factors. The chimpanzee version of HIV was found in a remote forest, and until colonialism brought change to that part of Africa there weren’t any people there. Suddenly you had porters being force-marched into parts of the forest where people didn’t go before, and steam ships going up the rivers. Diseases need a certain number of humans to sustain progress, and you also need a degree of human density more generally, like you have in a city of significant size. We know from the historical record that in colonial Congo during the end of the 1800s and early part of the 1900s there was the spread of sexually transmitted diseases—gonorrhea, syphilis and chlamydia—up and down steamship routes on the rivers. It’s now clear that HIV was moving along these same paths.

Another factor is that HIV spreads much more easily in societies where people have more than one sexual partner at a time. Parts of Africa that were predominantly polygamous featured a culture in which it was not unusual for both men and women to have more than one sexual relationship in an ongoing way. That ended up being crucial in allowing HIV to spread.

The other factor that eventually became consequential is that HIV spreads much more easily in places where men are less likely to be circumcised. In the Congo Basin and much of Africa most men are circumcised, but when you move into East Africa they don’t circumcise and you get HIV rates that are five, ten, or fifteen percent, as opposed to one or two percent in Congo. Likewise, the ethnic groups in southern Africa historically did circumcise, but with the onset of westernization and urbanization it fell out of fashion. So in the parts of Africa where male circumcision rates are low you get these explosive HIV epidemics.

Talk about the impact of circumcision on the spread of the virus.
HIV is actually relatively hard to spread. In the average relationship a man and woman can have sex hundreds of times and not necessarily spread HIV between them. But not being circumcised changes those odds in a way that ends up being consequential. Men who have foreskins are 70-75 percent more likely to get HIV.

The Western world was slow to pick up on the connection between HIV’s spread and male circumcision. After the initial research suggested there was a connection it took more than a decade before you got the second wave of research, where they took three-thousand males and circumcised half of them and then measured how quickly they acquired HIV or didn’t acquire HIV. When we finally got around to doing that kind of experimentation the research findings were so incredibly bright that they had to shut down all three of the medical trials early, because the men who were not circumcised were getting HIV so much faster than the ones who didn’t. It became unethical to keep those experiments going. But it shouldn’t have taken the world a dozen years to put together that kind of research. It seems to me that if AIDS had been less politicized and the conversation had been less clouded by people’s ideology, we would have moved more swiftly toward policies that would have led to less HIV spreading around the world.

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