Pathogens are the obstacle. Human flourishing is the end.
Lately, I’ve been thinking deeply about what it means to be an infectious disease physician. Not the day-to-day work of managing drug-resistant bacteria, post-operative infections, or fevers in transplant patients, but the larger question beneath all of it. What exactly is the purpose of infectious disease medicine? What is its ultimate aim?
First, every infectious disease physician stands as an intellectual descendent of a great lineage stretching back to Jenner, Pasteur, Koch, and Fleming and to D.A. Henderson. Those epoch-making minds were trying to solve real human problems that diminished the ability of humans to flourish. Their solutions — which include the germ theory of disease, vaccinology, and antibiotics—unequivocally augmented the length of human lifespans, diminished infant mortality, and facilitated much of modern medicine from chemotherapy to organ transplants to joint replacements.
As such, they advanced civilization. Every infectious disease physician, in their taming of even the most mundane of infections, is doing the same.
For much of human history, infectious diseases were a rate limiting check on human societies. A society might become too populous and invite crowd diseases such as measles, smallpox, and diphtheria to spread and cull the population. A society might become geographically tied to malarious areas or committed to cultural or gastronomical practices that increased interactions with specific animals, mosquitoes, and other vector species.
There have been 10,000 generations of humans and it is only the last 3-4 generations that humans have had some level of control and mastery of infectious diseases. What has transpired in that short period of time is arguably one of the most profound transformations in human history: a partial liberation from the microbial forces that shaped every preceding generation.
In fact, it probably wasn’t actually dread as those humans were acclimatized to that baseline level of suffering, death, disruption, suboptimal lifespan, and atrocious level of infant and childhood mortality that throttled their individual achievements and ability to reach the full potential of human life. That acclimatization still exists today in malaria endemic areas as Botswana’s President Boko recently argued).
Yet describing infectious disease as a constraint on human societies only raises a deeper question. Why does it matter that we have gained some measure of mastery over microbes? What is the purpose of that mastery? Is the goal of infectious disease
medicine simply the prevention of illness and death, or is it directed toward some higher end?
Aristotle, in the Nicomachean Ethics, argued that every craft, discipline, and human endeavor aims at some good, a telos or goal. Behind all of the intermediate or instrumental goals that people pursue lies an ultimate end: eudaimonia—human flourishing or living well.
If Aristotle is right then infectious disease medicine must also have a telos. That telos cannot simply be the eradication of pathogens any more than the purpose of architecture is the production of bricks. Pathogens are the obstacle. The end is something larger than being a pathogen hunter: preserving the conditions under which human beings and human societies can flourish.
An infectious disease physician, in my view, is a guardian of the conditions that allow civilization to flourish in the presence of pathogens. We are, to borrow the title of science writer Maryn McKenna’s excellent book on the CDC’s Epidemic Intelligence Service (EIS), “beating back the devil” in order to advance human civilization. During the COVID-19 pandemic, this role became explicit. Infectious disease physicians were called upon not merely to treat patients, but to help societies reopen schools, workplaces, hospitals, and public life itself, in effect being relied upon to bring civilization back in the wake of the pandemic.
There’s a scene in the movie Ghostbusters: Afterlife (I know, I try to tie this movie franchise to everything), where the teenage granddaughter of Dr. Egon Spengler, Phoebe Spengler, is asked to explain what she’s doing — battling ghosts and investigating the paranormal—she replies simply “I am a scientist”. That scene encapsulates everything of what it is, to me, to be an infectious disease physician.
In that sense, I believe highest achievement of infectious disease medicine is not the conquest of microbes themselves, but the expansion of human freedom, civilization, and possibility through mastery of the microbial world. The late Jonathan Mann, the iconic former chief of the UNAIDS precursor agency at WHO, former state epidemiologist of New Mexico, and CDC leader once said what I evaluate as one of the greatest ways to describe the field of infectious disease. Writing about HIV/AIDS—but it applies to all infectious diseases—Dr. Mann said, “When the history of AIDS and the global response is written, our most precious contribution may well be that, at a time of plague, we did not flee, we did not hide, we did not separate ourselves.”
That, ultimately, is what infectious disease medicine is.