In the last couple of decades, we’ve seen a surge in new infectious diseases, from various strains of Ebola to the notorious COVID-19. It’s not just a matter of better detection methods; genetic studies confirm that many of these pathogens are indeed new to humans. What’s even more alarming is that these diseases seem to be cropping up more frequently.
My work in anthropology has led me to believe that the primary reasons behind these outbreaks are deeply rooted in human behavior: how we feed ourselves, how we live together, and how we treat each other. In our upcoming book, “Emerging Infections: Three Epidemiological Transitions from Prehistory to the Present,” my colleagues and I delve into how these factors have shaped disease dynamics over thousands of years. Essentially, 21st-century technologies have simply amplified age-old challenges.
Let’s take a trip back to the Neolithic era, around 12,000 years ago, when humans shifted from hunting and gathering to farming. This transition brought about a whole new wave of infectious diseases. Before farming, infections were usually mild and chronic, more like long-term nuisances. But agriculture introduced acute and virulent infections, leading to what we now recognize as our first major epidemiological transition.
It wasn’t farming itself that caused these outbreaks; rather, it was the significant lifestyle changes that came with it. Agriculture provided a reliable source of high-calorie grains, but often at the expense of dietary diversity, weakening immunity due to nutritional deficiencies. The population exploded, leading to larger and denser communities where deadlier pathogens could thrive. And let’s not forget about the domestication of animals, which brought humans into close contact with new diseases.
Fast forward to the 19th and 20th centuries, when infectious diseases started declining, especially in wealthier nations. This wasn’t just because of antibiotics and vaccines—although those played a role—but also thanks to improvements in farming practices, sanitation, and housing. It was a testament to how non-medical interventions could make a significant impact on public health.
In essence, the rise and fall of infectious diseases throughout history are closely tied to how we live our lives and interact with our environment. It’s a sobering reminder that addressing these underlying factors is key to preventing future pandemics.
