The Rules of Contagion, Why Things Spread – and Why They Stop by Adam Kucharski
The Rules of Contagion – a scary title given the current novel coronavirus pandemic. It’s no secret that Covid-19 is causing problems the world over. But, I’m going to state this early; if you read only one non-fiction book during this crisis, please make it this one.
I first purchased The Rules of Contagion by Adam Kucharski when it was first published in February 2020. At the time, there had been some news stories about a novel coronavirus outbreak in Wuhan, China but it hadn’t yet become a global crisis. I had ignored it ever since, staring at me from my coffee table as the news documented the speed of the spread of the pandemic. This weekend I finally snapped, fed up of hearing terms like ‘herd immunity’ and ‘flatten the curve’ without really understanding what they meant. I can honestly say that I am so glad that I finally read The Rules of Contagion – it has provided much needed context and history to the current situation.
Kucharski breaks through the noise of the modern environment. An expert voice, with clarity, balance, evidence, and calm. He is “an associated professor at the London School of Hygiene & Tropical Medicine. A mathematician by training, his work on global outbreaks such as the Ebola epidemic and the Zika virus has taken him from villages in the Pacific Island to hospitals in Latin America”. Having previously won awards for his writing, his style is easy to follow and clear to a non-scientist. Throughout the book there are lots of useful diagrams and graphs to illustrate the points he is making. Additionally, the use of historical anecdote and tales, really helps to keep the book grounded in human experience.
The Rules of Contagion looks at contagion in multiple industries and sectors including: medical, financial, social, and historical. It’s not very often that you can read about STIs and Little Red Riding Hood in the same book! Kucharski starts with the medical form of contagion, exploring HIV, Zika, and Spanish Flu amongst others. He explains the history of ‘herd immunity’ as well as the statistical and scientific evidence behind it. I found this exceptionally helpful, especially given the British governments initial use of ‘herd immunity’as their solution to the coronavirus pandemic.
Equally helpful is Kucharski’s explanation of ‘R’ – “R therefore depends on four factors: the duration of time a person is infectious; the average number of opportunities they have to spread the infection each day they’re infectious; the probability an opportunity results in transmission; and the average susceptibility of the population”. He goes on to illustrate how different public health initiatives have used each of these variables to impact the level of contagion of measles, gun violence, and even viral social media posts. Understanding the interplay of these elements, was fantastic context to the current social-distancing and isolation measures being implemented throughout the UK.
A large proportion of the book is spent explaining statistical models and how they are used – historically and currently – to map the impact of contagious events. Kucharski was open highlighting the imperfections of models, and even providing examples of the CDC. Key to the success of any model is the data that is available. I had recently read an article outlining how our current death rates were wrong and we were focusing on the wrong numbers. As silly as it sounds, reading an expert detail that they’re aware of flaws in data was extremely reassuring.
Kucharski highlights the importance of big-data to public health, but also how recent scandals and concerns for privacy could play into a lack of willingness to share in the future. Despite reading about big-data in Mindf*ck and Everybody Lies, I hadn’t previously considered the implications in a medical context. As the world becomes ever more interconnected, it will be interesting to follow how we can use big-data for the benefit of society.
I was expecting to read The Rules of Contagion and feel anxious, panicky, and scared. However, I actually feel reassured, calm, and educated. Knowledge is power, and having a better basic understanding of the science and history behind pandemics, and the experts working to stop them is empowering. I said it at the beginning of this review, but will repeat it now – if you read only one non-fiction book during this crisis, please make it this one.
‘The Rules of Contagion’ in Facts: