[The author responds:]
I agree with most of John Anderson's assertions, especially the last sentence, and if my writing reinforced anyone's stereotypes that was unintended. My purpose was to provide a partial explanation of diabetes as a novel epidemic in North American aboriginal groups and to argue that the epidemic of type 2 diabetes world wide has its main roots in genetic predisposition, dietary change, obesity and sedentarism.[1, 2] I am sure that CMAJ readers would realize that the disease is also correlated intimately with socioeconomic variables.
Anderson may be correct that I should not have included tuberculosis in my list of infections unknown to "New World" tribes before European contact; in addition to the remains he mentioned, tubercular DNA was extracted from various human bones from Chiribaya Alta in southern coastal Peru. However, some researchers still consider that the presence of tuberculosis in the Americas before Columbus is unproven.3
I chose to refer to syphilis partly because, aside from tobacco, it was the only New World export that had a devastating effect in Europe. There are as many bittersweet ironies about the chronicles of tuberculosis and syphilis as there are about diabetes. The 2 infections have been linked, and confused, for centuries. In 1527 Jacques de Béthencourt provided a remarkably accurate description of the pox, stressing its polymorphic character, that it could cause osseous deformity and cavitation, and that it shared some characteristics of consumption. The answer to one of M. tuberculosis' enduring mysteries - how and when it migrated globally4 - may remain forever obscured by the organism's antiquity. It is curious that syphilis and tuberculosis penetrated European populations thoroughly, whereas native North Americans - judging from history and the examination of human remains - were more resistant to both infections. While 1 in 4 16th-century Europeans were dying from tuberculosis, their Mesoamerican contemporaries were dying in large numbers from the more direct results of contact with the conquistadores. Although the Peruvian boy mentioned by Dr. Anderson took his last tubercular breath around 700 AD, his culture expired when Francisco Pizarro's troops executed Atahualpa, the last Incan Emperor, in 1532.
There is stong evidence that syphilis was brought to Europe on Columbus' caravels. Contemporary European authors agreed that the disease was new. For example, Gonzalo Fernandez de Oviedo y Valdes was at court when Hernando and Isabel received Columbus after his first voyage. After interviewing the sailors and their captives he considered it to be "certain that this malady - the bubas - comes from the Indes, where it is very common amongst the Indians."5
When Columbus died, crippled by gout and arthritis, in 1506, it is unlikely that he had any idea of the consequences of his ventures. Nonetheless, the world had been "changed, uprooted and catapulted out of life-patterns that had endured for thousands of years."6