Hanan Rakine
Melissa Renko
AP Biology
25 May 2015

Spillover Summary
Spillover has woven a story of incredible complexity; a detective story with a difference, with a host of murderers – all of them real. They are viruses, bacteria and single-celled organisms which infect other animals, but every now and then make the jump – spill over – to our own species. Each chapter follows the quest to track down a new villain. An international team of detectives works on the cases, and Quammen follows them as they uncover the traces which will lead them to the killers.
The book opens with a horrific virus which lays low horses and humans, the Ebola virus emerges through a dark tale, with piles of dead gorillas in the forest, consumption of rotting bushmeat, sorcery and Rosicrucianism. The story is grim enough without the usually exaggerated descriptions of Ebola: sufferers crying blood and melting from the inside out. Quammen doesn't sensationalise his material (you could argue he doesn't need to – it's quite dreadful enough). He's much more interested in demystifying these outbreaks, finding out what we know about them and how this might help us to anticipate future emergent diseases and limit their impact. He promises to tell us the "complicated story", not the dramatic one. But this is such a consummate piece of science writing that you're likely to imbibe some extremely complex concepts without realising it. There's no "here's the science bit"; lessons in virology, epidemiology and genetics are woven seamlessly into the story.
In each chapter a disease gradually comes into focus, starting with rumours, a few seemingly unconnected, mysterious deaths. The history of the investigation unfolds until we come face to face with the killer. In the process we learn the myriad ways in which a germ can move from one host to another – through excrement, excretions, mucus and blood – and uncover the dangerous activities that may have led to exposure: climbing trees? touching or eating dead animals? drinking date-palm sap? Quammen also hunts down the unwitting accomplices: the animals who carry these diseases before they jump into humans: pigs, birds, monkeys, apes and bats. The real heroes of the piece are the detectives – the scientists working tirelessly out in the field and in their labs to solve the crimes committed by those microscopic murderers. As brilliant as Quammen is at describing the workings of viruses, he's also a masterful portrait painter, a close observer of people. These range from the molecular scientist working on Sars "with the instincts of an epidemiologist and the balls of a brass macaque" to the ecologist who relishes eating his way through the exotic biota on offer on Chinese menus to the expert in veterinary diseases who is a "sturdy fellow… looking like a former high school quarterback grown fortyish and serious."
Quammen takes us on a global journey, visiting orderly labs but also getting out into the field with researchers – trapping bats in China and monkeys in Bangladesh, travelling deep into

the Cameroon forest to hear tales of initiation ceremonies requiring bushmeat in the form of chimpanzee arms.
Towards the end of the book the author loses touch with reality and goes off on a fictional flight of fancy about the origin of HIV, mixed up with his own journey along the Congo river. It all gets a bit Apocalypse Now in this diverting but incongruous departure from the unwavering attention to evidence in the rest of the book.The emergence of zoonotic diseases – these afflictions which jump from other species to us – is not a new phenomenon but they do seem to be on the increase, and Quammen explores the reasons behind this in his final chapter: a huge global human population, a huge global population of livestock, destruction of natural habitats, disrupted ecosystems – it could easily become a diatribe about nature's revenge on humankind.
But Quammen isn't a romantic, sentimental environmentalist. He is careful to emphasize that humans are part of the natural world, not separate from it – and there lies the problem.
David Quammen delivers a brilliant, informative presentation of different animals, explaining clearly in simple terms how a disease spills over from animal to human. Through compelling stories weaved together, the author gives a gripping account of new infectious diseases, different animals in relation to specific diseases, and fascinating science reporting of examinations conducted by scientists. In addition, information reported from extensive research is provided on apes, horses, bats and other animals. The author presents engaging stories as he writes with compassion and sympathy about different diseases and the dangers of spillover.
Discussions about outbreaks of infectious diseases are provided, along with information on dealing with ongoing threats. It was extremely interesting to learn about the results of examinations, and progress made by the professionals as they face several challenges. It was also scary to ponder on the growing trend of diseases that spill from animal to human, a major concern is noted while contemplating on why these diseases emerge. Of course, the reader becomes curious about a new outbreak, which makes this intelligent presentation thoughtprovoking throughout. Interesting, educational, and highly recommended to science lovers! I can't recommend this book highly enough. Quammen's writing is vivid yet measured, detailed yet gripping, and he possesses true talent as a narrative non-fiction writer. His ability to explain complex scientific ideas and processes in layman's terms is fantastic, and made this book such a joy to read. He possesses the ability to take an intimidating topic such as zoonoses and spillover and captivate his audience with mind gripping narratives of exact moments where diseases in one species of animals takes up residence in another host species. From bird, to plant, to primate, to homo sapien, when the jump from one to the next takes place, David Quammen is there, giving the reader a detailed description of what had or may have taken place. He brings you from a horse pasture in Australia, to the deepest parts of the jungles in Africa, to depict the exact moment where the meeting of one disease carrying species meets another and their lives are forever intertwined with the infections they harbor together. What I appreciate most is how
David Quammen reminds his reader that humans are by far the most invasive species on earth as we continue to grow and reproduce and consume the resources this earth has to offer. In an ever shrinking world, we encroach on other species environments destroying their habitat as we unearth disease causing organisms, both old and new. If your desire is to learn more about zoonoses and spillover but find text book reading to be intimidating and overbearing or dry, read
David Quammen's Spillover and you will not be sorry.