Putative native South Amerindian origin of head lice clade F: evidence from head lice nits infesting human shrunken heads

Nadia Amanzougaghene,Didier Raoult,Philippe Charlier,Florence Fenollar,Oleg Mediannikov

doi:10.1038/s41598-022-08176-2

Abstract

The head louse, Pediculus humanus capitis, is a strictly obligate human ectoparasite with a long history of association with humans. Here, 17 ancient head lice nits were recovered from six shrunken human heads (known as tsantsas) of individuals from the Shuar/Jivaro tribe, a native Amazonian population from Ecuador, South America. Cytochrome b DNA analysis revealed the presence of three known mitochondrial clades. Clade A was the most frequent (52.94%), followed by F (35.29%), and B (11.76%). Eleven haplotypes were found in 17 samples, and nine of the haplotypes were novel, indicating an unusually high genetic diversity. In conclusion, we confirmed the presence of clades A, B and F in South Amerindian population. Moreover, the description of clade F, together with its previous reports in another Amerindian population from French Guiana, strongly support the hypothesis of a native South American origin for this clade, and probably derived from clade B which was carried to America by an ancestral Eurasian Beringian population. Further support to our conclusion and new insights might come from the analysis of a larger collection of modern and ancient native American lice.

Highlights

The head louse, Pediculus humanus capitis, is a strictly obligate human ectoparasite with a long history of association with humans
We obtained and analysed the genetic diversity of ancient head lice nits collected from shrunken heads of individuals from the Shuar/Jivaro tribe, a native Amazonian population from Ecuador
The mitochondrial DNA analysis, 17 head lice nit samples collected from 6 mono and/or double infested human shrunken heads (Fig. 1), showed that nine of the ancient louse nits (52.94%) belonged to clade A, two (11.76%) belonged to clade B and six (35.29%) belonged to clade F (Table 1)

Summary

Introduction

The head louse, Pediculus humanus capitis, is a strictly obligate human ectoparasite with a long history of association with humans. Molecular studies have been carried out in ancient head lice from Peruvian mummies, showing that clades A and B had a preColumbian presence on the American c ontinent[33,34], suggesting an American origin for clade B 33. A more detailed analysis of genetic diversity in P. humanus infesting native American population will provide insights into the evolutionary pattern of lice clades, their origin and will clarify additional events of human colonization of the Americas. We obtained and analysed the genetic diversity of ancient head lice nits collected from shrunken heads of individuals from the Shuar/Jivaro tribe, a native Amazonian population from Ecuador

Methods

Results

Conclusion