Molecular Identification of Head Lice from Peruvian Mummy
June 1, 2008 4 minutes read
Molecular Identification of Head Lice from Peruvian Mummy
Abstract & Commentary
By Joseph H. John, MD, FACP, FIDSA, FSHEA, Associate Chief of Staff for Education, Ralph H. Johnson Veterans Administration Medical Center; Professor of Medicine, Medical University of South Carolina, Charleston, is Associate Editor for Infectious Disease Alert.
Dr. John is a consultant for Cubist, Genzyme, and bioMerieux, and is on the speaker's bureau for Cubist, GSK, Merck, Bayer, and Wyeth.
Source: Raoult D, et al. Molecular identification of lice from pre-Columbian mummies. J Infect Dis. 2008;197:535-543.
Mummies are fascinating. they represent a special snapshot of our human past when contemporaries respected our human forms enough to try to preserve them indefinitely. The Inca and their ancestors, like the Moche (A.D. 100-700), developed a sophisticated mummy technology. The ruins at Machu Picchu, and surrounding areas deep in the Peruvian Andes, have multiple examples of niches in common rooms where mummies were thought to be placed. Like the Egyptians, early mummies were placed deep into pyramids, but later, the Inca, who tended to sacrifice young maidens for their offering to posterity, marched their chosen victims from central Peru to the towering volcanoes of southern Peru, near the present city of Ariquepa. Like many of their other ingenious traits, the Inca were great climbers and were able to bury the sacrificial girl at great heights, then preserve her at the right depth in the permafrost. The most famous of these mummies is Juanita, who is stored with a score of other young female mummies at the Catholic Museum in Ariquepa (Museo Santuarios de Altura). (See the web site Juanita, Inca Ice Maiden at http://www.mummytombs.com). Juanita was discovered in a now famous find by Johan Reinhard and his assistant Miguel Zarate on September 8, 1995, on Mount Ampato. I have had the occasion recently to see another Juanita-type mummy at the museum in Ariquepa, and was amazed by the quality of the preservation, particularly the lovely woven outer garments.
Visiting Machu Picchu as I did recently, I reflected on the marked quality of life the Inca must have had. As good of an environment as they produced, they still had lice. The magnificent investigator from Marseille, Didier Raoult, along with David L. Reed from the Florida Museum of natural History and a talented team, have studied lice from pre-Columbian mummies. Such work was initiated by Reed and published in 2004 (PLoS Biol 2004;2:e340). In that earlier work, it was established that there was contact between what Reed and colleagues describe as "direct contact between modern and archaic humans," using genetic analysis of head lice, Pediculus humanus capitis. Three distinct clades, haplotypes A, B, and C have been established to date. Haplotype A is found around the world and haplotype B connects Europe to North and South America. Because lice allow construction of evolutionary patterns, further study like this one has the potential to elucidate events in human history that are unknown and to deepen our understanding of host-parasite relationships.
The current mummies were excavated from the southern Peruvian coast 1999-2002. They were referable to a culture around the time of the Tiwanaku Chiribaya. Lice were collected from the only parts available, two heads, and two independent labs analyzed the DNA from the lice. PCR was used to amplify two cytochrome genes Cytb and CytbR2. The ancient DNA was unambiguously aligned with DNA from sequences found in GenBank representative of chimp, rodent, and human DNA. The DNA analysis from the Florida Museum and from Marseille showed no variation in the primary sequences or from cloned sequences.
Commentary
The current study found that, in these oldest lice ever examined, haplotype A prevailed, suggesting that before Columbus there was a reigning type worldwide. Body lice of haplotype A have been long standing in Europe, and Raoult and colleagues suggest that contact between Norway, Greenland, and the Americas, even during the Middle Ages, may have spread haplotype A lice. There was an absence of type B haplotype in the present study, which does not mean that type B lice is not found in South America, particularly as it would have been transported by the Spanish to Incan Peru. The source of type B lice found in Europe and Australia is unknown, so the search for more connections to this puzzle must go on. An intriguing theory advanced by Raoult et al is that haplotype B originated in South America and then spread throughout Europe. More analyses will be needed to support this theory.
Until there is more information about these, and possible other new clades of lice, they will still serve as the best ever preserved example of human parasites for evolutionary studies. It is amazing that the connections already established by the lice DNA analysis have revealed such old connections between human populations. Combined with current and future analysis of host genomes, we can start to piece a better picture of human migration, as well as understand better the diseases that still affect us.
Our local Charleston newspaper, the Post and Courier, recently published an excellent photo expose' called Lousy Lice by Brenda Rindge, April 28, 2008. Since lice can affect all humans from all walks of life, the infestation in children is still one of Mom's worst nightmares, as the P&C article intimates. Clinicians remain wary since lice are vectors for epidemic typhus, trench fever, and relapsing fever. Lice are surely to persist for us humans and, thus, the specter of new infectious diseases spread by lice looms as very possible in our futures.
Additional Source
Image Sources
- Katharina Ditmar, SUNY Buffalo;
- Sonia Guillen, Centro Mallqui, Peru
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