Introduction

Infectious diseases ranging from respiratory (influenza, common cold, tuberculosis, the respiratory syncytial virus), vector-borne (plague, malaria, dengue, chikungunya, and Zika) to sexually transmitted (the human immunodeficiency virus, syphilis) have historically affected the human population in profound ways. For example, the Great Plague, well known as the Black Death, was caused by the bacterium Yersinia pestis and killed up to 200 million people in Eurasia and about 30–60% of Europe’s population during a 5-year span in the fourteenth century. At the time, the plague infection was thought to be due to some “bad air”, but it was not discovered that bites of infected fleas were behind the pandemic until late 1890s. If the human civilization had known about the transmission mechanisms behind the plague infections, the epidemic’s impact on morbidity and mortality could have been mitigated through basic public health interventions. This is to say that knowledge of the transmission processes and the natural history of infectious diseases in different environments represents invaluable actionable information for thwarting the spread of infectious diseases.