What Diseases Mean in the Modern World

An author discusses how outbreaks threaten economic development and public health.

Video: Health Epidemics

Video: Health Epidemics

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While often overlooked, disease has had important influences on the development of society through the course of history. U.S. News spoke with Irwin Sherman, a professor emeritus of biology at the University of California-Riverside, about his new book, Twelve Diseases That Changed Our World, and some of the devastating dozen it names.

How did you decide which diseases to feature in the book?
The choices of the 12 diseases in this book were somewhat arbitrary. I chose diseases that I felt had made a significant impact not only on the population and not only on history, but that there was some [good] that was obtained from it. I chose yellow fever as well as malaria since both were important [inspirations for improving mosquito] control. But there may have been other diseases that I could have chosen but didn't—let's say sleeping sickness, which has probably prevented much of the exploration and development of Africa.

In the United States, most people haven't experienced widespread pandemics, but other countries still struggle with malaria, tuberculosis, and even measles. How is this affecting their development?
I think that many of these countries are hampered in their economic development as a result of infectious diseases. They place a tremendous burden on the societies. Consider someone infected by malaria. There will be great absenteeism and lethargy, then there's the burden on the healthcare system. The same thing is true of HIV/AIDS—you lose valuable members of the population; parents are lost, schoolteachers are lost, and so are ordinary workers, which makes productivity decline.

A year or two ago, people spoke in fear of avian influenza. Before that, there was SARS. What's the next world-changing disease likely to be?
It's very difficult to say. I don't think anyone would have predicted SARS. Most people believe that continuing contact with animals—and this has been historically true—will result in diseases jumping from one species to another. Having domesticated and wild animals in close contact with human populations will probably result in this. We've seen this before with hantavirus, a rodent disease. Whether they will be of the magnitude of an influenza or even SARS remains to be seen, [but] we're better prepared for some of these than we have been in the past. There's a great boon in understanding the [infectious] nature of the agent. Imagine SARS appearing 300 years ago and the panic that would have occurred.

Many of the nasty microbes you wrote about spread through the movement of people—whether for war, trade, or settlement. How do you envision increasingly globalized trade, the ease of world travel, and fluxes of refugees and immigrants influencing future disease outbreaks?
I think they all accentuate the emergence of disease. Yellow fever was transported from Africa to the Americas in cisterns on ships because the mosquito could breed in them. Back then, an infected individual would probably die on the ship. Today you can travel from one country to another in a matter of hours. In San Diego, there are always introductions of malaria from Mexico and Central America and from India. But these don't cause epidemics because the numbers are few, the diagnosis is usually pretty quick, and we have reasonably good drugs that can control the disease. Nevertheless, it still represents a threat.