ABSTRACT
Infectious diseases are more than their pathogenic agents alone. Despite the general nosology or scientific naming of diseases after their pathogens (Vibrio cholera, Yersinia pestis, etc.), diseases are due to relationships between viruses, bacteria, fungi, or protozoa and their human hosts. These relationships can often vary radically over time and place, depending on environmental and genetic changes in both pathogens and hosts. 1 As a consequence, changing signs and symptoms, rates of mortality, morbidity, lethality, and changes such as the poor becoming the ones overwhelmingly afflicted can transform ailments beyond recognition. For instance, during the first half of the sixteenth century, physicians and other commentators saw the venereal disease that we now generally label as syphilis changing fundamentally. In his study of contagious diseases of 1546, Girolamo Fracastoro maintained that the prominent characteristic that had given the disease one of its most common names – the Great Pox – had largely disappeared over the past 20 years: now pustules appear ‘in very few cases’. He added that the horrible pains with sleepless nights so often described by doctors and evoked in the poetry of those afflicted ‘had somewhat subsided’. In their place, new symptoms surfaced such as the disappearance of eyebrows and hair on top ‘falling out’, making ‘men look ridiculous’. 2
