RESUMEN
A holistic approach is necessary to investigate health in archeological populations. Molecular techniques, particularly multiplex PCR and SNaPshot minisequencing, can be combined with paleopathology and dietary analysis (stable isotope, starch, zooarchaeological analyses) to understand aspects of population health. This article demonstrates how spina bifida, a multi-factorial disease characterized by the midline failure to complete vertebral neural arch formation, can be investigated holistically. Based on skeletal evidence, this disease was prevalent in a pre-Columbian Cuban population from the archeological site of Canimar Abajo (3000-1250 BP). Molecular paleopathological techniques were employed to examine disease potential in this preliminary study, examining 18 individuals (including two individuals with evidence of mild spina bifida, and 16 without such evidence) for four single nucleotide polymorphisms and one insertion sequence associated with spina bifida. The combined effect of these polymorphisms, as well as dietary factors, determines the risk of the population for spina bifida, and these factors united to create the observed high disease prevalence. We demonstrate how molecular paleopathology, corroborated by dietary analyses, can be used within a paleoepidemiological framework to understand population health and disease.
RESUMEN
BACKGROUND: Leishmaniasis is an infectious disease endemic today in many areas of South America. METHODOLOGY: We discovered morphologic and molecular evidence of ancient infections in 4 female skulls in the archaeological cemetery of Coyo Oriente, in the desert of San Pedro de Atacama, Northern Chile. The boney facial lesions visible in the skulls could have been caused by a number of chronic infections including chronic Leishmaniasis. This diagnosis was confirmed using PCR-sequenced analyses of bone fragments from the skulls of the affected individuals.Leishmaniasis is not normally found in the high-altitude desert of Northern Chile; where the harsh climate does not allow the parasite to complete its life cycle. The presence of Leishmaniasis in ancient skulls from the region implies infection by the protozoan in an endemic area-likely, in our subjects, to have been the lowlands of North-Eastern Argentina or in Southern Bolivia. CONCLUSIONS: We propose that the presence of the disease in ancient times in the high altitude desert of San Pedro de Atacama is the result of an exogamic system of patrilocal marriages, where women from different cultures followed their husbands to their ancestral homes, allowing immigrant women, infected early in life, to be incorporated in the Atacama desert society before they became disfigured by the disease. The present globalization of goods and services and the extraordinary facile movement of people across borders and continents have lead to a resurgence of infectious diseases and re-emergence of infections such as Leishmaniasis. We show here that such factors were already present millennia ago, shaping demographic trends and the epidemiology of infections just as they do today.