People, gorillas, horses, duikers, pigs, monkeys, chimps, bats and viruses: We're all in this together-The Spillover Review

The Spillover: Animal Infections and the Next Human Pandemic by David Quammen is an extraordinary piquant, epic in scope and occasionally humorous read that will take you through an adventure on 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.

Quammen talks to the scientists pushing our understanding forward and lets you listen in. He goes into detail on biology and ecology, so that you understand in some depth how these systems work, without overwhelming you. And he does all of that in the middle of telling some fascinating stories. Most importantly, the moment of the current situation will make the book a more relatable read.

The primary thesis of this book is pretty straight forward. Our relationship with the rest of the natural world, which is consumptive, intrusive, and disruptive. Those things shake loose viruses from their natural hosts. All these wild animals carry their unique viruses. When we go into a tropical forest with its great diversity, and we start cutting down trees and capturing animals or killing animals for food, we offer those viruses the opportunity to become our viruses. To jump into us and find a new host, a much more abundant host. And when a virus moves from an infected animal into a human, it's won the sweepstakes. It can now spread around the world and become one of the world's most successful viruses, which this coronavirus now is.

Spillover is topical. It's about zoonoses or diseases that jump from animals to people. He talks specifically about the outbreaks of Ebola, MERS, SARS, HIV and others in recent history, all of which were zoonoses. Other diseases — malaria, the Black Plague, the flu- recur in discussions throughout the book. All of these have existed for a long time in some animal species. All infected humans in some unlucky interaction, maybe more than once, and then spread more or less well among us.

According to Quammen, "A zoonosis is an animal infection transmissible to humans. There are more such diseases than you might expect. AIDS is one. Influenza is a whole category of others. Pondering them as a group tends to reaffirm the old Darwinian truth (the darkest of his truths, well known and persistently forgotten) that humanity IS a kind of animal, inextricably connected with other animals; in origin and in descent, in sickness and in health." 

Quammen published Spillover in 2012. By then, we had learned enough about zoonoses to know that they were common and likely to become more so as more humans intrude more deeply into the animal habitat, and as our factory farms get bigger and denser.

Towards the end of the book, Quammen writes:

"I have asked, many other eminent disease scientists, including some of the world's experts on Ebola, on SARS, on bat-borne viruses generally, on the HIVs, and on viral evolution, the same two-part question: (1) Will a new disease emerge, in the near future, sufficiently virulent and transmissible to cause a pandemic on the scale of AIDS or the 1918 flu, killing tens of millions of people? and (2) If so, what does it look like and whence does it come?

Their answers to the first part have ranged from Maybe to Probably. Their answers to the second have focused on RNA viruses, especially those for which the reservoir host is some kind of primate. None of them has disputed the premise, by the way, that if there is a Next Big One (NBO), it will be zoonotic."

Deja Vu, here we are!!

One entire section of the book describes the threat that coronaviruses pose and the outbreak of SARS in the early 2000s. That chapter is "Dinner at the Rat Farm." If you wanted to read just part of the book, to understand what's happening today, that's where you ought to go.

But don't. The entire thing is excellent and worth reading. It's not a cheerful book, but it's useful. We have had all sorts of opportunities in the past to learn the lessons of zoonosis. The spread of COVID-19 gives us one more chance to see the effects of a pandemic and to think about how we protect against them in the future.

My advice about the book, get a copy and enjoy your physical distance moment with it. It is worth every microsecond of your time.

Favourite Quotes:

"Make no mistake, they are connected, these disease outbreaks coming one after another. And they are not simply happening to us; they represent the unintended results of things we are doing. They reflect the convergence of two forms of crisis on our planet. The first crisis is ecological; the second is medical."

"Our findings highlight the critical need for health monitoring and identification of new, potentially zoonotic pathogens in wildlife populations, as a forecast measure for EIDs." That sounds reasonable: Let's keep an eye on wild creatures. As we besiege them, as we corner them, as we exterminate them and eat them, we're getting their diseases."

"People and gorillas, horses and duikers and pigs, monkeys and chimps and bats and viruses: We're all in this together."

“The transmission of SARS, Dwyer said, seems to depend much on super spreaders—and their behaviour, not to mention the behaviour of people around them, can be various. The mathematical ecologist’s term for variousness of behaviour is “heterogeneity,” and Dwyer’s models have shown that heterogeneity of behaviour, even among forest insects, let alone among humans, can be very important in damping the spread of infectious disease."

“Our findings highlight the critical need for health monitoring and identification of new, potentially zoonotic pathogens in wildlife populations, as a forecast measure for EIDs.” That sounds reasonable: Let’s keep an eye on wild creatures. As we besiege them, as we corner them, as we exterminate them and eat them, we’re getting their diseases.”

"Disappointment, in science, is sometimes a gateway to insight."