I have done work for much of the last 15 years in global health, and wrote a book about the AIDS Pandemic in Latin America. I’ve returned to thinking about HIV recently because I’ve just given a lecture on the Global AIDS pandemic, during which I discussed media coverage of not only the new gene therapy to fight HIV, but also the discovery of an HIV strain in Cuba that seems to lead to AIDS more rapidly than is typical. Behind these news stories remains the fact that over 35 million people are now living with HIV. It is true that impressive advances in both medicine and public health now mean that there is more hope concerning the epidemic than at any time before. Still, despite the merited attention given to the Ebola outbreak in West Africa, it’s worth remembering that over a million people died of AIDS last year, far more than all the Ebola outbreaks in recorded history combined. How did this outbreak begin? Since I first began to study the virus a great deal has been learned about its evolutionary history, and the circuitous path that the virus took from an unknown individual in Cameroon to become a global pandemic.
David Quammen explores this question in his new book, the Chimp and the River. Quammen is a well-known science writer, whose previous book Spillover attracted a great deal of critical praise. This book began as a chapter within that work, which he has expanded upon. The strength of this work is the clarity of his writing. Discussing key concepts within the HIV epidemic -clades, retroviruses, transmission routes- can be difficult. Quammen has a knack for choosing metaphors that convey complicated concepts, without being condescending to the reader. He has also interviewed many of the key scientific players, and traveled the route that the virus took from southeastern Cameroon to the Congo.
One weakness to the book is that the origin of HIV/AIDS is not a new topic, and this a tale frequently told, as Quammen acknowledges himself. To anyone working in the field, there will be little in this concise book that is truly new. At the same time, the advances as knowledge over the last decade have been truly amazing. Although this knowledge is conditional, it now seems very likely that the main strain of HIV, which dominates the current pandemic, crossed over from a single human-animal interaction in southern Cameroon in 1908. The virus then traveled to Kinshasa, where it circulated in low numbers in the 1960s, before making the jump to the Americas around 1969. The fact that this can be known with some confidence is an amazing story of medical detective work, which Quammen tells with skill. His sense of wonder that so much can now be understood about the virus’s origins is infectious. There is also diversity in the strains of HIV that now circulate. His point that each of these strains likely reflects a separate introduction of HIV into humanity is a useful reminder that -much as with Ebola- HIV is best not thought of as a single event, but as a zoonotic disease that has appeared episodically. The history of the virus also cannot be understood apart from multiple human activities -syringes, colonial medicine and a plasma collection facility in Haiti- which may have transformed the virus, and almost certainly played a key role in amplifying the epidemic.
Quammen also attempts to recreate the early history of the virus by telling the story of the individual who brought the virus out of Cameroon. This section of the book is a fictional account that builds upon his own experience traveling the same river route in Africa. Quammen writes well, but for me this section of the book was less necessary than the wonder of the science that made it possible to imagine this story in the first place. Nonetheless, I thought that this work was a clearly written, well-organized and thoughtful introduction to the scientific knowledge of the origins of HIV, which I would strongly recommend to anyone interested in science writing, infectious disease or HIV/AIDS.
Shawn Smallman, Portland State University