Book Review: The Plague Cycle: The Unending War Between Humanity and Infectious Disease, by Charles Kenny

March 29, 2021

     By Duncan Green     

Charles Kenny is a wonderfully fluent and accessible writer. He’s also quick, judging by his latest book, The Plague Cycle: The Unending War Between Humanity and Infectious Disease. Here’s how it opens:

‘The two leading killers worldwide at the start of the twenty-first century are heart attacks and strokes. That is evidence of humanity’s greatest triumph: until recent decades, most people didn’t live long enough to die of heart failure. Rather, they were felled by a range of infectious diseases that picked off the young or swept through whole populations in pandemic catastrophe.

Covid-19 is a terrible reminder that our victory against infection is far from complete—and in all likelihood never will be complete. The cycle of population growth, pandemic, and recovery isn’t nearly as violent as it has been in the past, but it’s still with us. Many more infectious diseases have emerged over the past century than have been eradicated. And the coronavirus has demonstrated the immense costs we bear when people are forced to rely on one of the very earliest responses to infection: running from it.’

He’s an optimistic liberal, occasionally verging on the Panglossian. He looks at the big historical sweep to show that things are ‘Getting Better’ (the title of a previous book). Many of his concerns about the broader impact of Covid-19 are over the pandemic’s potential impact on that liberal agenda – outbreaks of scapegoating, closing of borders, a reversal of a globalization that he sees as a force for good. Instead he sets out a convincing argument for why Covid and the pandemics that follow will need more globalization, eg a massive upgrade of the WHO, not less.

He’s read a lot of history for this book, looking through a health lens to interweave infectious disease with human progress, war and the rise and fall of states and nations. The result is occasionally indigestible, ‘here’s some more facts’ writing, but also interspersed with lurid accounts from plague diaries through the ages, and some real surprises. Did you know that Gandhi was an anti-vaxxer? ‘Vaccination is a barbarous practice, and it is one of the most fatal of all the delusions current in our time.’ Oops.

Mostly, though, The Plague Cycle charts the human response to infection, and the stellar progress of the last two centuries:

‘If the nineteenth century’s progress against infection was largely a victory of engineering and city management, the twentieth century’s was mostly about vaccine workers, community volunteers, pharmacists, researchers, and the drug industry.’

His optimism is laced with anxiety, in particular over the mindless use of antibiotics in agriculture, triggering resistant strains of bacteria that are threatening to send us back to having to use maggots to cleaning out putrescent flesh from human wounds, because the drugs don’t work any more.

That’s enough summary – here’s a long-ish extract from the conclusion to give you a proper taste.

‘The tragedy of Covid-19 helps illustrate the utterly different world we’ve become used to living in. The most alarming early forecasts suggested that if governments and individuals did nothing to respond to the new threat, as many as 2.2 million Americans might die from the coronavirus. That amounts to about six out of every one thousand people in the country. Such forecasts were one factor behind an appropriately massive global response. But in the US in 1900, eight out of every one thousand people died from an infectious disease, and that wasn’t an unusual year. For much of human history, it’s unlikely that an illness like Covid-19 would have been recognized as a new and distinct health threat at all.

If we continue on the path away from Malthusian doom, which we know how to do, how will the world appear different? With declining birth rates and longer lives, it will undoubtedly be older—but the changes go beyond that. Given the links between infection risk and xenophobia born in prehistory, a less infectious world will be friendlier, more cooperative, and less violent. And given the close link between the rise of infection and the subjugation of women at the dawn of civilization, perhaps it will be more equal. If the pandemic tragedies on the scale of Justinian’s plague, the Black Death, and the Atlantic disease exchange go unrepeated, it will be more stable. As good health boosts productivity, countries will be richer and more urbanized—and the gap between industrial and developing countries should continue to shrink. It won’t be a perfect world, but it will continue getting better.

Or perhaps Covid-19 is only a foretaste of even worse to come. Perhaps we’ll backslide. If anti-vaccine prophets peddle their deadly disinformation without response, if our last antibiotics are wasted on adding a few ounces of white meat to a chicken breast, if we do nothing to improve global cooperation, surveillance coverage, and rapid response to outbreaks, we know what the world will look like. A planet without our most effective tools against infection is one moving back toward Malthusian misery. It’s a world where our view of mortality as an increasingly private affair is blown away by mass burial of the young. It’s a world that is poorer, more violent, more insular—a bigoted and misogynistic place.’

And his last para:

‘Covid-19 temporarily and tragically reversed progress against infection. But still, far fewer parents than ever before in history go through the pain of burying their own children. The massive decline in premature death is something we should celebrate and protect as humanity’s greatest triumph.’

March 29, 2021
Duncan Green