Into past, into future, a virus on the loose

Into past, into future, a virus on the loose

The rules of contagion: Why things spread and why they stop Adam Kucharski. Profile Books/Hachette India. Pages 352. Rs 599

Book Title: The rules of contagion: Why things spread and why they stop

Author: Adam Kucharski

Aditi Tandon 

As the world struggles to halt the march of Covid-19, Adam Kucharski’s The Rules of Contagion takes us to a riveting journey through the heart of epidemics helping us fathom what sparks and stops contagion.

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 An epidemiologist at the London School of Tropical Medicine and Hygiene, Kucharski examines outbreaks across sectors — biological, financial, social and political — before leaving the reader with an abiding message. “In outbreak analysis, the most significant moments are not the ones where we were right,” he says. “It is those moments when we realise we have been wrong, when something does not look quite right. Whether we want an innovation to take off or an infection to decline these are the moments we need to reach as early as possible. The moments that allow us to unravel chains of transmission, searching for weak links, the moments that let us look back, to work out how outbreaks happened in the past. Then look forward to change how they happen in future.”

The dominant force in the book is British doctor Ronald Ross who bagged the 1902 Nobel for discovering the route of malarial transmission. Kucharski tells us how Ross was the first specialist to pioneer mathematical modelling when he wanted to show that malaria could be controlled without swatting every mosquito. This was an early insight into what we know as herd immunity, the concept now integral to disease control.

The book reveals little-known histories behind landmark scientific efforts. So it speaks of British anaesthetist John Snow, the first to conclude that cholera was caused by contaminated water and not bad air as was popularly believed those days. Snow’s story flows as a remarkable tribute to researchers who challenged popular notions of their times in pursuit of truth behind contagion.

Kucharski also straddles financial, online and social spaces to explore contagion across fields and show how ideas mastered in studies of infectious diseases are now helping control other kinds of outbreaks.

Police authorities across American cities are now viewing violence as an infection rather than as a result of bad people, much like the rejection of the bad air causing cholera theory. A gripping vignette in the book is on Cure Violence, a project epidemiologist Gary Slutkin pioneered in Chicago where he used small pox eradication tools to reduce gun violence by two thirds.

The book details how epidemiological concepts like reproduction number are helping researchers quantify the spread of innovations and online content and how methods used to study genetic sequences of pathogens are helping solve violent crimes.

The author makes stunning but demonstrable conclusions in this addictive book. He shows that it is increasingly possible to measure and compare contagion across industries using ideas from one area of life to help understand another.

So we now know why WHO issued guidelines on responsible reporting of suicides after a 1974 work found when newspapers ran front page stories on suicides, the number of such deaths in local neighbourhoods increased immediately afterwards.

The best story this book tells is of Issac Newton losing a fortune when the world’s first financial bubble burst in 1719 and of the scientist thereafter exclaiming: “I can calculate the motion of heavenly bodies but not the madness of people!”

And then there’s this warning by the writer to the world: “In my field there’s a saying — if you have seen one pandemic, you have seen one pandemic.”

Bottomline: No one disease, no one online worm is similar. The contagion will mutate, so must science.