The other day I finished reading a riveting book, Spillover: Animal Infections & The Next Human Pandemic by David Quammen. A terrifying account of the recent history of disease scientists investigating bizarre and unheard of new diseases of animal origins, a thriller written by a gifted storyteller. Quammen explained the science so well in layman’s terms. This is one of those rare books I couldn’t put down. The fact that it was published eight years before our current worldwide coronavirus pandemic, a fair warning, makes it all the more pertinent.
Spillover is the process by which pathogens, hiding in wild animal reservoirs (also in factory farmed animals), travel into and infect the human population. But near the end of the book, after discussing the plagues of gyspy moths, which come and go, Quammen introduced the concept of outbreaks. We had a memorable outbreak of gypsy moths here in Connecticut in the 1980s so I could easily grasp the concept.
Ecologists have a label for such an event. They call it an outbreak.
This use of the word is more general than what’s meant by an outbreak of disease. You could think of disease outbreaks as a subset. Outbreak in the broader sense applies to any vast, sudden population increase by a single species. Such outbreaks occur among certain animals but not among others. Lemmings undergo outbreaks; river otters don’t. Some kinds of grasshopper do, some kinds of mouse, some kinds of starfish, whereas other kinds of grasshopper, mouse, and starfish do not. An outbreak of woodpeckers is unlikely. An outbreak of wolverines, unlikely. The insect order Lepidoptera (moths and butterflies) contains some notable outbreakers — not just tent caterpillars of several kinds but also gypsy moths, tussock moths, larch budmoths, and others.
We are prodigious, we are unprecedented. We are phenomenal. No other primate has ever weighed upon the planet to anything like this degree. In ecological terms, we are almost paradoxical: large-bodied and long-lived but grotesquely abundant. We are an outbreak.
And here’s the thing about outbreaks: They end. In some cases they end after many years, in other cases they end rather soon. In some cases they end gradually, in other cases they end with a crash. In certain cases, even, they end and recur and end again, as though following a regular schedule.
What could account for such sudden and recurrent collapses? One possible factor is infectious disease. It turns out that viruses, in particular, play that role among outbreak populations of forest insects.
~ David Quammen
(Spillover: Animal Infections & The Next Human Pandemic)
Chills have been running up and down my spine ever since I read the excerpts quoted above. We are an outbreak on this earth. Our population explosion can be fairly compared to an infestation of gyspy moths. Provocative thought, I know. But it’s humbling and sobering to appreciate that we are part the cycles of nature and while we like to think we can control our environment to some degree, when all is said and done, we know so little about the forces shaping our existence here on this little blue planet.
We now have 114 confirmed cases of COVID-19 in our town. Our county (New London) has 1,276 confirmed cases. Of those 7 are still in the hospital and 102 have lost their lives. Hospitalizations are way down here, which is encouraging, but we are still staying home due to our health risks. Please stay safe!
