The coronavirus disease, known as COVID-19, is a frightening reminder of the imminent global threat posed by emerging infectious diseases. Although epidemics have arisen during all of human history, they now seem to be on the rise. In just the past 20 years, coronaviruses alone have caused three major outbreaks worldwide. Even more troubling, the duration between these three pandemics has gotten shorter.
I am a virologist and associate director of the Animal Diagnostic Laboratory at Penn State University, and my laboratory studies zoonotic viruses, those that jump from animals and infect people. Most of the pandemics have at least one thing in common: They began their deadly work in Asia or Africa. The reasons why may surprise you.
