We evaluated the presence and distribution of Trypanosoma cruzi DNA in a mummy presenting with megacolon that was dated as approximately 560 ± 40 years old. The mummy was from the Peruaçu Valley in the state of Minas Gerais, Brazil. All samples were positive for T. cruzi minicircle DNA, demonstrating the presence and broad dissemination of the parasite in this body. From one sample, a mini-exon gene fragment was recovered and characterized by sequencing and was found to belong to the T. cruzi I genotype. This finding suggests that T. cruzi I infected humans during the pre-Columbian times and that, in addition to T. cruzi infection, Chagas disease in Brazil most likely preceded European colonization.

Tuberculosis is a prehistoric American human disease. This paper reviews the literature and discusses hypotheses for origins and epidemiological patterns of prehistoric tuberculosis. From the last decades, 24 papers about prehistoric tuberculosis were published and 133 cases were reviewed. In South America most are isolated case studies, contrary to North America where more skeletal series were analyzed. Disease was usually located at the deserts of Chile and Peru, Central Plains in USA, and Lake Ontario in Canada. Skeletal remains represent most of the cases, but 16 mummies have also been described. Thirty individuals had lung disease, 19 of them diagnosed by the ribs. More then 100 individuals had osseous tuberculosis and 26 also had it in other organs. As today, transmission of the infection and establishment of the disease were favored by cultural and life-style changes such as sedentarization, crowding, undernutrition, use of dark and insulated houses, and by the frequency of interpersonal contacts. The papers confirm that despite previous perceptions, tuberculosis seems to have occured in America for millennia. It only had epidemiological expression when special conditions favored its expansion. Occurring as epidemic bursts or low endemic disease, it had differential impact on groups or social segments in America for at least two millennia.

Paleopathology is the study of disease, physiological disruptions and impairment in the past. After two centuries of mainly descriptive studies, efforts are being made towards better methodological approaches to the study of diseases in human populations of ancient times whose remains are recovered by archaeology. Paleoepidemiology can be defined as an interdisciplinary area that aims to develop more suitable epidemiological methods, and to apply those in current use, to the study of disease determinants in human populations in the past. In spite of the limits of funerary or other archaeological series of human remains, paleoepidemiology tries to reconstruct past conditions of disease and health in those populations and its relation to lifestyle and environment. Although considering the limits of studying populations of deceased, most of them represented exclusively by bones and teeth, the frequency of lesions and other biological signs of interest to investigations on health, and their relative distribution in the skeletal remains by age and sex, can be calculated, and interpreted according to the ecological and cultural information available in each case. Building better models for bone pathology and bone epidemiology, besides a more complex theoretical frame for paleoepidemiological studies is a big job for the future that will need the incorporation of methods and technology from many areas, including the tools of molecular biology.