Science’s Triumph Over Infectious Disease Has a Downside

Harriet Hall

Plagues and the Paradox of Progress: Why the World Is Getting Healthier in Worrisome Ways, by Thomas J. Bollyky (MIT Press, Cambridge, 2018. ISBN 978-0-262-03844-4). 272 pages. $27.95


This book explains the history of infectious diseases and plagues and shows how science has worked to overcome them; the author, Thomas Bollyky, argues that the progress has been amazing but that it’s also worrisome.

Infectious Diseases Are Declining

Bollyky provides a wealth of information to show that infectious diseases are in decline. He describes the history of infectious diseases and plagues in detail. For the first time ever, infectious diseases have declined significantly even in the poorest populations. They now account for only 8 percent of death and disability.

Even as it was in decline, smallpox killed 300 million people in the twentieth century, far more than all those killed in that century’s wars. Thanks to vaccines and public health campaigns, the last case of smallpox occurred in 1979. No one will ever get smallpox again.

Infectious diseases can spread from animals to humans and vice versa. Bollyky presents some interesting facts about smallpox. It originated as a gerbil virus. Edward Jenner’s original vaccine, thought to be derived from cowpox, was probably actually horsepox. After the Emperor of China died of smallpox, Japan sent a mission to Europe to study vaccines, and they soon adopted compulsory vaccination.

Sewer systems, safe water systems, and simple oral rehydration treatments have drastically reduced the number of cholera victims. Polio is nearing eradication. Measles could easily be eradicated were it not for anti-vaccine propaganda.

Even in the African countries most affected by HIV/AIDS, life expectancy has rebounded to exceed pre-epidemic levels.

The Black Death killed a substantial portion of the world’s population; nothing comparable has happened since, despite new threats from emerging infections such as HIV/AIDS, Ebola, Zika, and others. We could face a new epidemic or plague at any time, and countries must cooperate for the world to be prepared.


Bollyky shows how infectious diseases and efforts to fight them have played an important role in shaping the modern world. But “the way infectious diseases are declining in recent decades is different from how they have declined in the past, and that difference, when combined with broader global changes, is producing deeply worrisome consequences for the future.”

The escape from infectious disease in wealthy countries was accompanied by better public health institutions, responsive governance, and improvements in living standards—things that are lacking in poorer countries.

Fewer people are dying, particularly among children. Of course, that’s undeniably a good thing. But there are reasons to worry. Many developing countries lack the basic consumer protections and public health regulations to deal with the changes. Especially in sub-Saharan Africa, there is little access to preventive care and greater exposure to health risks such as smoking (tobacco companies have been aggressive in marketing there). People in those countries are more likely to develop cancer, heart disease, and other noncommunicable diseases than people in wealthier countries. With limited resources and poor access to medical care, they are also more likely to die earlier or become disabled.

As fewer children die of infectious disease, they grow up and the adult population increases. This presents challenges for nations that have not built health care systems to treat chronic adult diseases, urban infrastructure to house everyone, or robust economies to employ job-seekers.

Underemployment leads to economic migration. This far exceeds refugee migration and affects the entire world but gets much less media attention. People are moving from the country into cities as well as from one nation to another. Previously, people migrating to cities for economic reasons found factory jobs that offered a hard life but provided a lifeline to more prosperity. Today, migrants seeking better jobs often don’t find them. Bollyky quotes economist Joan Robinson: “The misery of being exploited by capitalists is nothing compared to the misery of not being exploited at all.”

In 1900, only 3 percent of people lived in cities. In 2008, for the first time, more than half of all people lived in cities and towns. Urbanization originally offered better jobs but poorer health, which some considered an acceptable trade-off. Many people moving to cities today find no jobs but still poorer health than in the country.

“The path that many countries took in the past—employing their demographic dividend in manufacturing and exporting their way to the middle-class—may be closing.” Today there is competition from robots and low-wage manufacturing from China and other countries that achieved health gains earlier.

Poor world cities are more likely to host instability, violence, and uprising due to crowded slums and autocratic governments. Ninety-five percent of the most populous cities exposed to coastal flooding are in poor and emerging economies. Paradoxically, Dhaka in Bangladesh not only suffers from flooding, but its urban water supply is failing. Air pollution has been markedly reduced in developed countries but is a growing problem in third world countries; we hear about the poor air quality in Beijing, but the air quality in Delhi and Cairo is far worse. The number of urban dwellers in Bangladesh without adequate sanitation more than doubled from 1.1 million in 1990 to 2.3 million in 2015.

China is an exception to the general rule. It went from a poor, famine-ravaged country to one of the world’s largest economies. An aggressive public health policy and the one-child policy allowed it to take advantage of a demographic dividend. A demographic dividend is not a guarantee of economic growth. The governments of other nations did not respond as quickly, and Latin American nations were not as lucky.


Bollyky doesn’t just criticize; he offers solutions:

  • International development initiatives must be more responsive to the changing needs of lower-income nations. Listening to the local people, education, improving infrastructure, providing health services for non-infectious diseases, and thoughtful and targeted investments are all important.
  • Helping emerging nations confront the demographic changes that have accompanied declining rates of infectious disease. Funding data collection and research, studying which interventions are successful.
  • Politicians in wealthy nations must come to terms with the inconsistencies in their policies on climate change, global health, trade, and immigration.

Conclusion: Good Information but Not a Very Good Book

I can’t wholeheartedly recommend this book. Bollyky provides a lot of information and makes some very persuasive arguments, and I agree that there is cause for worry and a need to address the problems he identifies. But the book didn’t engage me. I found it a chore to read rather than a pleasure; it was difficult to read, dense, repetitive, not as well organized as it could be, didn’t flow well, and hard to follow in places. The title of the last chapter is “The Exoneration of William H. Stewart,” the surgeon general who has been widely quoted for something he never said: “We have wiped out infection.” The chapter could have omitted that exoneration, and the title could have reflected what the chapter is really about: suggestions for solutions. It’s a valuable book, but it would have benefitted from a more appealing style or a more discerning editor.

Harriet Hall

Harriet Hall, MD, also known as the “SkepDoc,” is a retired Air Force family physician and flight surgeon who writes about pseudoscientific and so-called alternative medicine. She is a contributing editor and columnist for the Skeptical Inquirer.

Plagues and the Paradox of Progress: Why the World Is Getting Healthier in Worrisome Ways, by Thomas J. Bollyky (MIT Press, Cambridge, 2018. ISBN 978-0-262-03844-4). 272 pages. $27.95   This book explains the history of infectious diseases and plagues and shows how science has worked to overcome them; the author, Thomas Bollyky, argues that the …

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