One of history’s most destructive forces, the zoonosis (a pathogen transmitted from an animal reservoir host, directly or indirectly, into a human) has caused epidemics for millennia and killed patients innumerable. Following the invention of microscopes, the bacterium came to light, but the elusive virus––too small to be caught in filters and solidly immune to antibiotics––has evaded us until relatively recently. In David Quammen’s extensive tome of zoonosis case studies, the history and struggle of isolating and retracing the steps of animal-human pathogens is as vital as the science itself. For better or worse, if you want to know why the original, early 2000s SARS didn’t wreak as much havoc as its ever-present, currently raging sequel, COVID-19 (or SARS-CoV-2), Spillover stipulates that you read the virologist’s life story and indulge a few historical excursions, too.
Spillover isn’t exclusively about the mechanisms of pathogens themselves, nor is it really a work of popular science, where a book attempts to make a complicated topic more manageable to the casual reader. It’s more an extended work of science reporting, where the news is the discovery and the journalist recounts the major figures and key choices in the history of how it happened. Quammen, as a National Geographic staff writer, structures the nine sections of his book like the unrestrained, elaborate features a reporter like him might whip up without page limits. Despite Quammen’s commitment to storytelling, and his careful attention to the ironic anecdote, the magazine features some of the sections previously were aren’t sufficiently tweaked to fit the structure of a long work of nonfiction. Some of the techniques that work on magazine readers––telling an interesting anecdote out of left field and holding off on revealing its larger importance, for instance––become almost tiresome when they require twenty pages of investment in a book, as opposed to a magazine’s, say, three.
The issue with this approach isn’t with Quammen’s handling of the material. The various connections between lives, research, and place really do bring a subject like epidemiology some relatability: Quammen’s commitment to showing us the monkeys in the temples, and explaining, historically, why they’re there, does more for our understanding than strictly discussing encephalitis and its inner workings. But truly accessible science writing is more than just the inclusion of non-science subjects. History and biography can be made too dense to read through as well, even by sheer virtue of volume.
Still, Quammen takes some admirable risks in wrapping science in storytelling (how one might hide a dog’s medication in peanut butter), and he manages to build in the basics gradually, instead of pounding them all in at the beginning like a pre-book crash course. He even gracefully introduces the S.I.R model, an exercise in blunt force calculus he jokes about having to translate (for good reason). This scientific discovery psychodrama also happens to work well when Quammen wants to track the rise and fall of misguided ideas, namely the informally dubbed “Don’t kill your host” principle, and how it fell out of favor after five strains of a virus that infects rabbits demonstrated that a lower virulence, or intensity, isn’t necessarily a virus’ best bet for continued survival.
In one of the most inspired passages of the book, after a brief history of how wild rabbits exploded across Australia, Quammen explores how a virus released into the population to keep it under control quickly evolved different strains of varying potency. By first establishing the idea that viruses killing their hosts was thought to be an unfortunate coincidence that ultimately detriments the virus, Quammen sets up something akin to suspense as each of the strains tear through the wild and are tested against their hosts. This specific sequence is one in which Spillover‘s broad focus works at its best, seeking out events that can be reported as opposed to science that can be broken down and explained in abstraction.
Not every excursion in the book is like this, but when the timing is right, and the important ideas are truly built into their context, Spillover can impart these big ideas with remarkable staying power.
The final lesson, even, is hardly final, ecosystems and shifting circumstances constantly changing as they do, but it really sticks. Quammen makes ample allowance for this, an attribute of value as it pertains to Spillover‘s resonance where the menacingly-inferred Next Big Pandemic has already arrived. Its ties to the current moment extend a little bit beyond the eerie details a contemporary reader might glean while reading the section in SARS and its family of coronaviruses. Some of Quammen’s stretches for meaning near the end are really pushing it (“humans are an outbreak” comes to mind), but his words on the impact of our acts in the course of a pandemic read like the attitudes we’re being urged to adopt today––reservoir hosts in the animal kingdom don’t generally realize they’re in the midst of an outbreak and adjust their behavior accordingly. We, crucially, can.
It seems like magical forecasting for a moment, until you remember that humanity is a tried-and-true survivor of plague, with the experience and the preventative measures to prove it. As Spillover can attest to, history has a lot to tell us about crisis and recovery––it’s simply a matter of paying attention.