Ancient parasite infections from the main Pampean-Patagonian cemetery of hunter-gatherer of prehistoric times: Archaeological site Chenque I (Parque Nacional Lihué Calel, La Pampa Province, Argentina)

Abstract

Paleoparasitological studies of human sediment samples from prehistoric times of Argentina are scarce. The objective of the present study is to enhance the knowledge of parasitic infections affecting hunter-gatherer populations inhabiting the Pampean region of Argentina in prehistoric times. A total of 33 samples from 12 inhumation structures of archaeological site Chenque I, the unique cementery studied in Argentina until now from a paleoparasitological point of view, were studied. Chenque I constitute the greater repository of human archaeological remains of La Pampa province. Thirty-one samples came from human burials, and 2 samples from a dog retrieved in a burial, associated with a child. By humans, 11 samples correspond to males, 13 to females, and 7 to undifferentiated individuals. A total of 5 samples corresponds to control samples and were taken under the skull. Paleoparasitological examination revealed that 8 of the 33 sediment samples resulted positive for parasite remains applying the rehydration and spontaneous sedimentation technique with or without addition of HCl (10%). The pre-treatment of samples with HCl as a preliminary step allowed a greater recovery of parasitic remains compared to standard spontaneous sedimentation procedure. The most common parasite species found was Trichuris trichiura being probably one of the parasites that commonly affect human populations inhabiting the region. The low preservation evidenced by the parasite remains recovered indicate a taphonomic interference in the data of parasite assemblages, which probably produce a bias in the recovery of other parasite species that could infect these ancient populations. Proceed in the study of new human samples to improve the knowledge of parasitic infections affecting ancient populations inhabiting the studied region is necessary.