The Parable of the Clinician and the Epidemiologist
The brown river usually flows lazily through the middle of town. But today it is a torrent, carrying human bodies. Some, still alive, are gasping for air, thrashing the water.
Approaching the river to enjoy lunch on its banks, two doctors, horrified by what they see, begin to haul people out of the water. There are no signs of violence, but the victims’ eyes are glazed, their weak pulses racing.
The doctors cannot keep up with the flow of bodies. They save a few and watch helplessly as the others drift beyond them.
Suddenly, one of the doctors lowers an old man to the ground and starts to run. “What are you doing?” yells the other doctor. “For God’s sake, help me save these people!”
Without stopping, she yells back over her shoulder. “I’m going upstream to find out why they’re falling in.”
So begins Inside the Outbreaks, a fascinating book that chronicles the work of the men and women of the Epidemic Intelligence Service, a division of the US Centers for Disease Control. The men and women who make up the EIS are essentially detectives who track down the causes of major disease outbreaks – originally in the USA, and later throughout the world. Or think of them as firefighters, risking their lives by dropping into the heart of an epidemic in an attempt to snuff it out (by comparison, when I perform epidemiological studies, the only risk to my personal health is due to excessive sedentary time). The book does a fantastic job of illustrating why epidemiology is such an important (yet often overlooked) field, and also drives home just how far we have come in recent years in both the treatment and prevention of infectious disease.
The book follows the history of the EIS from it’s founding in 1951 until the present, describing interesting cases as it goes. Most of these cases read like the movie Outbreak in miniature – people become sick, EIS officers descend on the scene, and through careful observation they are able to determine the cause of the illness and often prevent its recurrence. That may sound a bit nerdy, but that’s because epidemiology is nerdy. But it is also fascinating, and Pendergrast does an excellent job of bringing the EIS story to life.
The book outlines dozens of cases, but what I find most interesting is when life threatening illnesses emerge in the most mundane places – like fatal Legionnaire’s disease spread by a mister spraying water on supermarket vegetables. Or a histoplasmosis epidemic at a middle school caused by bird poop stirred up during an Earth Day playground clean-up. Reading these cases it is hard not to be impressed by the work of the EIS, and easy to become apprehensive about these deadly epidemics that often seem to develop out of thin air.
The other thing that the book does very well is give a very healthy respect for diseases that we hardly ever have to deal with anymore in North America – things like smallpox, polio, and cholera. Cholera is a surprisingly fascinating disease – it gives you diarrhea that looks like it has rice in it… which is actually your intestines flaking off. One of my favourite quotes describes the volume of fluid lost when an individual is suffering from cholera: “One man set a record by expelling and replenishing 15 gallons [of poop and vomit] over a 48-hour period.” Not surprisingly, without treatment this severe dehydration can kill within 24 hours. And yet, mainly through the use of a simple treatment consisting of just water, salt, baking soda, sugar, and a source of potassium, EIS officers were able to reduce cholera-related deaths to 1% or less. And of course there is also plenty of information on the instrumental role that the EIS played in eradicating smallpox, a topic so important that I am embarrassed to admit how ignorant I was before reading the book (not surprisingly, the book also serves as a fascinating history of the important role of vaccination in public health).
Now this is not to say that the book is perfect. Inside the Outbreaks is setup chronologically, and each chapter goes through major cases within a specific period of the EIS’ history. As a result, each chapter is relatively self-contained, and there is little or no grand narrative tying these chapters together. I found this made the book feel a bit impersonal and awkward at first, as I kept waiting for the author to reveal the grand themes that would bring the separate episodes together, or to delve into the personalities behind the EIS. Once I got past the first few chapters though, I found the style a bit liberating – I could easily read 2-3 self-contained chapters during my lunch break, each time experiencing the sense of closure you get at the end of a good episode of CSI. That being said, I never felt like I absolutely had to read the next chapter, or that I had anything more than a superficial understanding of the EIS officers themselves. And finally, I would have also enjoyed a larger focus on the CDC’s current focus on chronic diseases like obesity, which received little attention.
Those imperfections aside, I still thoroughly enjoyed the book, and would recommend it to anyone interested in the history of medicine or public health, and especially those working in the field of epidemiology. For more on the book, you can check out the Scienceblogs Book Club, or visit the official website. And if you’ve read the book yourself, I’d love to hear what you thought of it in the comments section below.
Disclosure: My review copy of the book was provided by the author.