The Persistent Relevance of Infectious Disease: An Introduction

 Closing the Book on Infectious Disease

 If you lived in the United States in 1900, life was pretty rough. Back then, the average lifespan was 47 and the leading causes of death were influenza, tuberculosis, and gastrointestinal disorders. What happened? Well, we figured out our public health. Physicians started washing their hands. A scientist got mold on his bread, and then BAM, we had penicillin. Vaccines were developed and the populace was immunized. Death by infection plummeted down the lists to be outpaced by chronic disorders like cancer and heart disease. As medicine became more powerful, so too did human ambition to curb the old threats of the past. Aspirations were high. Polio vaccines saved lives. The World Health Organization began to put together campaigns to exterminate Malaria-carrying mosquitos as well as smallpox. As a testament to the times, the U.S. Surgeon General at the time said:

"It’s time to close the books on infectious diseases, declare the war against pestilence won, and shift national resources to such chronic problems as cancer and heart disease."

-Dr. William H. Stewart, U.S. Surgeon General (1965-1969)

It's a nice quote because it's a succinct snapshot of the attitudes of the time that puts us in the shoes of health authorities. In one sentence, we see the unbridled optimism and arrogance of medicine equipped with antibiotics and modern sanitation methods. It's perfect. As soon as I even considered blogging about infectious disease, I knew I had to include that quote. You may have even heard this quote before because hundreds of writers, teachers, and authors have referenced it. You also may have noticed that I didn't put a citation on the quote. That's because, unfortunately, Dr. Stewart never said it. Whoops.

Did you see that? Here I was, trying to make a blanket statement about the beliefs of the time. I had the perfect quote to unpack, a quote which I was familiar with and believed was true. Yet, it wasn't until I went to write this post and looked it up that I realized someone had debunked it as an urban legend four years ago. Dr. Stewart supposedly said the above text during a speech in 1968. However, the transcript of the speech does not contain the quote. In fact, it appears Dr. Stewart said the opposite. So where did this apocryphal quote originate? Apparently, from someone who didn't attend the speech and heard the quote from someone else. Evidently, someone who wasn't paying good attention.

Before we dive into the rich histories of these diseases and the people who suffer them, we should remember this example of how a fake quote became real. All of the people I linked above believed the quote, as did I until I learned otherwise. When we condemn an entire generation to one viewpoint, we need to be very careful with our sources. History is a product of humans, and humans are nuanced. Believing that everyone in a time period was of one thought and mind is a gross simplification for the messiness of reality. 

That complexity is where my interest in infectious disease stems. So let's get back to that.

What makes a disease?

The fundamental task of medicine and public health is drawing the line between wellness and disease. By its very definition, a disease is abnormal. It is bad. It is a state of being we strive to avoid, and the prime directive of public medicine is to prevent and treat it. Before a disease can be treated, it must be defined. And oftentimes, that definition is a matter of culture.

In order to define a disease, we must also come to an understanding of what is normal. Changes in culture invariably lead to a shift in how we define a disease or disorder. In the 1980s, the American Psychiatric Association added ADHD to the list of psychiatric disorders. It also removed homosexuality from that list. These changes in the listing do not mean that the symptoms and behaviors which constitute ADHD suddenly appeared in the 20th century. Nor does it signify that homosexuality is or has always been considered a disorder. These changes reflect shifts in culture and awareness.

Going about our day to day lives, we understand basic elements of sickness. When our fevers go past 100 degrees Fahrenheit (or 37 degrees for my metric friends out there), we feel muggy and sweaty and gross, or when our throats are sore we know something is wrong. But those are symptoms. More often than not, we feel a bit under the weather and it goes away without any need to bring physicians into the picture. Is that disease if there's no diagnosis? 

The paradox of good health is that we strive to possess it, but fail to notice it until it's gone. Disease touches every aspect of the human experience, and is there anything more human than fighting off a cold by curling under a blanket and sipping soup?

Disease is a source of morbidity and mortality. It is the lens through which we are forced to focus our lives and find meaning for them. In one way or another, medicine and health touch every aspect of our lives and civilization. But remember, this isn't a blog about just disease. I'm focusing on infectious diseases. So let's talk about why am I interested in that particular subset.

All diseases are complicated because they are the sum of a slew of personal, genetic, and cultural factors. What makes communicable disease interesting is in the name: they are (mostly) living things that spread from person to person. Many diseases can be tied to lifestyle choices, but you don't acquire them when a random person on the bus sneezes on you. Infectious disease is a direct, traceable consequence of our interactions with others and the environment. Cancer and heart disease are worthy topics for a blog, but they do not spread person to person (with three notable exceptions for cancer which I will probably discuss at some point). That is where my fascination with infectious disease stems from.

Why is infectious disease still relevant?

If you've paid any attention to the news for the last four decades, you may have noticed that our world is not an idyllic pasture bereft of pestilence. We found plenty of new nasties like HIV, Ebola, and Legionnaires. The old threats slain by antibiotics gained resistance. Previously rare viruses such as Zika found a niche and leaped to the headlines. As society has evolved, so has infectious disease. Globalization, air travel, and population booms have brought great strides to our civilizations. At the same time, these changes to our way of life have provided opportunities for both old and new parasites to establish themselves.

My plan for the future will be to focus on different pathogens and diseases with each post. My intention is to write so that people without a science background can follow and understand the various challenges and characteristics of modern communicable disease. I will also be touching on the nuances of various pathogens as they interact with our history, culture, and ways of life, so hopefully, those of you with solid foundations in science will also find something to take away from this blog. The first diseases we will discuss are what public health scientists call the Big Three: malaria, tuberculosis, and HIV. Of all infectious diseases, they are the greatest inflictors of morbidity and mortality on the planet as well as what sucks up the most public health funding. In these three diseases we also see a parasite, bacterium, and virus so we can speed through the basics of these three classes of pathogens as we talk about what makes each of the three unique for their class.

Now remember, I am NOT a physician and I am only human. That means nothing I post should be taken as medical advice. It also means I will likely make mistakes like all the people above who misquoted Dr. Stewart. I will be attempting to simplify complex scientific topics for the general public, and sometimes generalization will misconstrue the truth. If there's ever an error or you have trouble following something, tell me and I can fix or try to explain it another way. Blogs are good for that. 

So I guess I'll see you guys next time when we talk about our first disease and namesake for the blog: tuberculosis.