This review investigates ancient infectious diseases in the Americas dated to the pre-colonial period and considers what these findings can tell us about the history of the indigenous peoples of the Americas. It gives an overview but focuses on four microbial pathogens from this period: Helicobacter pylori, Mycobacterium tuberculosis, Trypanosoma cruzi and Coccidioides immitis, which cause stomach ulceration and gastric cancer, tuberculosis, Chaga’s disease, and valley fever, respectively. These pathogens were selected as Helicobacter pylori can give insight into ancient human migrations into the Americas, Mycobacterium tuberculosis is associated with population density and urban development, Trypanosoma cruzi can elucidate human living conditions, and Coccidioides immitis can indicate agricultural development. A range of methods are used to diagnose infectious disease in ancient human remains, with DNA analysis by PCR one of the most reliable, provided strict precautions are taken against cross contamination. The review concludes with a brief summary of the changes that took place after European exploration and colonization
