The Threat Throughout the last three thousand years, smallpox has shadowed civilization. A viral infection, the disease spread along trade routes, emerging first in Africa, Asia and Europe and reaching the Americas in the sixteenth century. Because smallpox requires a human host to survive it tended to smolder in densely populated areas, erupting in a full-blown epidemic every ten years or so. Wherever it appeared, the legacy of smallpox was death, blindness, sterility and scarring. While some medical practitioners claimed to cure smallpox, most medical traditions focused on prevention.
History of Medicine INTRODUCTION Tropical medicine began in the nineteenth century when doctors diagnosed infectious diseases in soldiers and colonists who had lived in tropical areas. In 1877, English scientist Sir Patrick Manson proved that mosquitoes spread elephantiasis to humans and he later theorized that the same was true with malaria. This was an enormous step in tropical medicine and the understanding of tropical diseases, leading to advances in prevention methods. The field of tropical medicine consists of the study, treatment, and prevention of tropical diseases. Tropical diseases can be defined as those that are mainly of parasitic origin and are common in tropical or subtropical areas.