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The history of syphilis has been well studied, but the exact origin of the disease remains unknown. [3] It appears to have originated in both Africa and America. [4] [5] As such, there are two primary hypotheses: one proposes that syphilis was carried to Europe from the Americas by the crew(s) of Christopher Columbus as a byproduct of the Columbian exchange, while the other proposes that ...
In some infectious diseases, the severity of symptoms has been shown to be dependent on specific genetic traits of the host. [6] [7] 4. Organisms that look alike but behave differently: In some cases a harmless organism exists which looks identical to a disease causing organism with a microscope, which complicates the discovery process. [8] 5.
The subclinical (pre-symptomatic) and clinical (symptomatic) evolution of disease is the natural progression of a disease without any medical intervention. It constitutes the course of biological events that occurs during the development of the origin of the diseases [4] to its outcome, whether that be recovery, chronicity, or death. [5]
The history of malaria extends from its prehistoric origin as a zoonotic disease in the primates of Africa through to the 21st century. A widespread and potentially lethal human infectious disease, at its peak malaria infested every continent except Antarctica. [1]
Aside from that, most of the major infectious diseases known today originated in the Old World (Africa, Asia, and Europe). The American era of limited infectious disease ended with the arrival of Europeans in the Americas and the Columbian exchange of microorganisms , including those that cause human diseases.
Throughout history, the disease tuberculosis has been variously known as consumption, phthisis, and the White Plague. It is generally accepted that the causative agent, Mycobacterium tuberculosis originated from other, more primitive organisms of the same genus Mycobacterium.
The disease, which originated in Asia, was first brought to Europe by the invading Huns in 370. Later invasions of Mongols , led by Genghis Khan and his army, started pandemics in Europe in 1222, 1233 and 1238.
The germ theory of disease proposes that invisible microorganisms (bacteria and viruses) are the cause of particular illnesses in both humans and animals. [2] Prior to medicine becoming hard science, there were many philosophical theories about how disease originated and was transmitted.