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It’s the Science, Stupid

I MET MY first AIDS patient on a bitter January morning in 1985. I was a third-year medical student rotating on the internal medicine service at Detroit’s Henry Ford Hospital. Unlike the Atlantic seaboard or the West Coast, AIDS was still a clinical novelty in Michigan. Consequently, when I heard the news that an AIDS patient was admitted to our ward, I rushed to his bedside. Looking back, I like to think my excitement stemmed from the fact that I was joining in on the pandemic of our era, just as my predecessors fought the Black Plague in the Middle Ages and cholera in the nineteenth century. But really I was just rushing to see what we doctors refer to as “a good case.” 

A few years later, as a physician working in Baltimore, I treated hundreds more AIDS and HIV-positive patients. Today highly active anti-retroviral therapies have converted HIV/AIDS (at least in wealthier nations) from a death sentence into a chronic disease. But back in the 1980s, doctors had little to offer beyond a kind heart, an attentive ear, and a few highly problematic drugs. An avalanche of intriguing inquiries emerged with each new patient, and yet I do not ever recall anyone wearing a white coat asking the central question that is asked by Jacques Pepin’s masterful new book: “How did AIDS transmogrify into the most deadly scourge in human history?” 

The failure of medical doctors to ask such an important question during the early years of the pandemic is easy to explain. Those who did care for these patients—a relatively small number at the time—were preoccupied with the pressures of providing for the hundreds of critically ill gay men, intravenous drug users, sex workers, and others arriving every day to our AIDS clinics. After the patients were seen, many doctors, nurses, and social workers spent long evenings waging time- and spirit-consuming battles to prevent the legal, social, and health insurance systems from causing further harm. At the same time I was an AIDS doctor, I was attending graduate school for a doctorate in medical history. Yet even in the book-lined seminar rooms where some of the greatest historians of medicine pontificated on virtually everything under the sun, questions of the infectious origins of AIDS were of little concern.

This silence proved especially noteworthy in the face of a number of sensational explanations and conspiracy theories. There were wild claims that the CIA created HIV as a genocidal weapon against so-called “undesirables.” More famously, the journalist Edward Hooper inspired headlines in 1999 with his book, The River: A Journey to the Source of HIV and AIDS, in which he insisted that HIV-1 originated during the 1950s from an experimental polio vaccine using chimpanzee cells. Although unanimously and scientifically rejected by the world’s leading virologists, Hooper’s fanciful thesis continued to strike a major chord, especially within the HIV/AIDS community. The embrace of these and other theories was hardly surprising in a population that had already experienced so much prejudice and outright cruelty on the part of government leaders, medical professionals, and society at large.

The lack of curiosity among trained medical historians, on the other hand, stems from the research priorities that have dominated the medical academic history world over the past four decades, where social and cultural markers have tended to trump the biological and clinical. Emblematic of this intellectual ethos was the axiom offered by the French historian Francois Delaporte in his book, Disease and Civilization: The Cholera in Paris, 1832: “Disease does not exist … what does exist … [are] practices.” It would have been more accurate, and more compassionate, to say that disease is socially constructed until you happen to find yourself in bed with one.

To be sure, the theory of the social construction of many medicalized entities, such as hysteria, addiction, depression, eating disorders, and even chronic diseases such as cancer, has proven to be in some ways enlightening. But an exclusive focus on social construction theory often falls short when examining contagious crises of the past because it de-emphasizes the critical role of an epidemic’s principal actor: the evolving pathogenic microbe. When tracking the history of an epidemic, one needs to study the social, economic, political, and cultural elements as well as the biology that set these events in motion. But it is the biology that is the main event.

Indeed, one of the great innovations of historical epidemiology over the past few years has been the application of genetic, microbiological, and other scientific tools to riddles ranging from what killed Tutankhamen (most likely malaria) to the unique structure and public health responses to the influenza virus that killed millions during the fall and winter of 1918-1919. Similarly, studies of DNA variation, paleopathology, and human and animal migration patterns have helped scientists to document the geographical paths of particular epidemics across great swathes of time.

Jacques Pepin, a professor of microbiology and infectious diseases at Canada’s Université de Sherbrooke, has tracked the HIV virus in sixteen African nations over the past three decades. He also possesses an encyclopedic command of the world’s literature on HIV/AIDS. Combining his vast experience and knowledge, Pepin has written a model study of epidemiology, microbiology, genetics, and social and cultural history. 

What is most original about The Origins of AIDS is how the author employs a completely different archive than those far more familiar to most historical scholars. Pepin’s quarry includes the vast collections of blood samples kept by several African nations when they began to see large numbers of AIDS cases, as well as other blood specimens collected for waves of Ebola fever in the 1970s, and samples from a number of inherited blood disease studies collected in the ’50s.

Pepin and his colleagues have imported this complex mass of historical information into the laboratory, where they used phylogenetic analysis (the application of nucleotide sequences to reconstruct the evolutionary forms of life, including microbial pathogens). In addition, Pepin reviewed thousands of clinical case histories and retrospective post mortem examinations spanning several decades. Equally important, he examines the incidence and genetics of the various strains of Simian Immunodeficiency Virus (SIV) in the chimpanzee and gorilla populations in Africa. 

Based upon a meticulous scientific analysis, Pepin concludes that a viral strain called SIVcpz, which infects large numbers of Pan troglodytes troglodytes chimpanzees living in central Africa, was the central source of HIV-1. This transmission, Pepin suggests, probably began sometime in the early 1920s, as more and more humans began to colonize central Africa and consume large amounts of bush meat. Chimpanzees and humans appear to contract and spread these viruses the same way: through sexual contact and the comingling of blood. Bush meat hunters are often bitten, scratched, and clawed by their prey, and those who butcher the meat expose themselves to body fluids; both activities present a very real risk of cross-species transmission.

In deference to Delaporte’s famous observation about the relationship between social practices and disease, Pepin understands that infectious diseases can be shaped and potentially amplified by social events. As he reviews the social history of African colonization by European nations, Pepin convincingly argues that the hunting of bush meat alone, even when combined with more human beings settling closer to species they had not previously encountered, was not enough to create a global pandemic. Some of the most intriguing chapters of Pepin’s book describe the effects of urbanization on African public health between 1920 and the present. He explores the frequency with which too many African men engaged in sexual intercourse with a widening network of impoverished women forced into prostitution. Meanwhile, long-distance travel (first by cross-continental trains and then road-bound cars and trucks) facilitated the mass movement of infected men to other regions where they had sex with still more prostitutes and eventually their own spouses, with disastrous consequences.  

Far better known is the path that HIV took out of Africa and into Europe, the Caribbean, and the United States. In all these regions, the infection was amplified owing to the sexual revolution, which profoundly changed the sexual practices of both the gay and straight communities; the rising abuse of illicit drugs, and a concomitant sharing of hypodermic syringes and needles; ever more rapid systems of transit around the globe; and a crowded menu of other social, political, and economic factors.

The Origins of AIDS bears brilliant witness to the costs of living in a world plagued by emerging and re-emerging infectious diseases. Pepin notes that a number of new infections could easily be transformed into human crises without careful attention to the biology and social practices that helped spread AIDS. He urges better funding and support of global infectious disease surveillance, treatment, and prevention programs, all designed to give our species a fighting chance in our endless struggle against contagion. One can only hope that we finally begin to pay attention to microbe hunters like Jacques Pepin and collectively address the daunting task of attempting to contain these grave threats.

Howard Markel, the George E. Wantz Distinguished Professor of the History of Medicine at the University of Michigan, is the author of When Germs Travel, and most recently, An Anatomy of Addiction: Sigmund Freud, William Halsted, and the Miracle Drug Cocaine.