Science reading 2: Spillover

I’ve been holding off on writing my next book review for a couple reasons, but the most important one is that I was finishing the book in question. I went back and forth about writing the review here. After all, this is pretty far from marine biology, and surely there are more relevant works I could point you towards. But this is the latest by my favorite science writer, and in the end I couldn’t pass it up.

I first encountered David Quammen at my undergrad institution. He had just published a short biography of Darwin and was, I guess, on his book tour. We were lucky enough to snag him as a speaker in our weekly colloquium series. I was doubly lucky in that I got to go to lunch with him (at the faculty club, so make that triply lucky). My loss, though, because I’d never heard of him before. Lunch was interesting, and I remember Quammen telling us some story of boating down the Amazon, and caimans, and pirahnas, or was it some other river in South America? His talk was about Darwin’s formulation of the theory of natural selection. Afterwards there was a book signing and I remember sort of wanting to buy one but it seemed like an absurd, expensive frivolity. I continue to regret that decision.

For Christmas that year I got the Darwin biography and a copy of The Song of the Dodo, both amazing, both long since read. I now own his book on man-eating predators (Monster of God) and one of his several collections of essays from Outside magazine. I’m hoping to write future posts about these but just in case I never get there, seriously go get these books. Read them.

Quammen started out in life as a graduate student in English, studying Faulkner, and it shows. The man can write. He also isn’t afraid to go anywhere in the world to get a science story, and the more remote, the better. Best of all, he’s just as interested in the scientists as he is in their research. His books, therefore, read as a wonderful mix of scientific fact and cultural anthropology of research scientists. And the science in them is not just accurate, but not all that simplified. Just explained really well.

I saw Quammen speak a second time in 2012, at the Evolution meeting in Ottawa. He talked about his soon-to-be-released book, Spillover: Animal Infections and the Next Human Pandemic. He talked about emerging zoonotic diseases. He talked about Ebola and walking through Congolese forests and HIV. There was no book signing, which was just as well because I’d forgotten mine back in the States.

Spillover, by David Quammen.
The topic really does need a scary cover.

It’s taken me until this year to read Spillover. I am so glad that I finally did. The book is about emerging diseases, particularly zoonoses, or diseases we get from animals. As he says so well, this category includes all kinds of nasty things: influenza, rabies, hanta, Lyme disease, SARS, AIDS, Ebola. But this isn’t just a study of the pathology of these diseases in humans. These diseases come from animals, by definition, and their emergence, virulence, and duration in the human species is a complicated mix of ecology and evolution, the story of humans and their altered environments. People interacting with animals and therefore with their diseases. The take-home message is that the more often that happens, the more likely a spillover of an animal virus into a human is, and the more likely that these viruses can be transmitted human-to-human. These diseases frequently have long evolutionary histories with their animal hosts, and in many cases are relatively benign. But in humans, it’s a different story.

Quammen bookends the meaty chapters in the book with the showstopping diseases: Ebola to start and AIDS to finish. These two are different in many ways, but similar too. They both seem to come from infected apes. They both have their origins in Africa. They both have sky-high fatality rates. In between these two monsters are lots of other diseases, some of which you know (Lyme, malaria, SARS) and some of which you probably don’t (Hendra, Nipah, Q fever). I am admittedly squeamish and had to skim the descriptions of human symptoms for most of these, but the ecological and evolutionary sections are lengthy and fascinating. For starters, why are so many of these viruses, rather than bacterial diseases?

This book is scary. I know I never want to be within miles of a bat in the tropics after reading it. (Spoiler: bats seem to be responsible for more than their share of these spillovers…or are they? The evidence isn’t completely clear.) But it ends on a somewhat hopeful note. He does say, based on interviews with many esteemed disease scientists, that the “Next Big One,” the next large human pandemic, will almost certainly be a zoonosis. There’s several reasons for that, discussed at length in the book. We have no idea what or where or when. But despite that, there are scientists on the case, standing ready, and working as hard as they can to minimize impact.

I’ll leave you with some of Quammen’s own words:

This whole subject [of zoonotic diseases], like an airborne virus, is at large on the breezes of discourse. Most people aren’t familiar with the word ‘zoonotic’ but they have heard of SARS, they have heard of West Nile Virus, they have heard of bird flu…They are concerned. They are vaguely aware. But they don’t have the time or the interest to consider a lot of scientific detail.

If that describes you, but you have time to read a book, go get this one. You will get lots of well-written, digestible scientific detail.