Human lice : differenciation, phylogeographic distribution, host-switching and control (original) (raw)
Related papers
The origin and distribution of human lice in the world
Infection, Genetics and Evolution, 2014
a b s t r a c t 29 Two genera of lice parasitize humans: Pthirus and Pediculus. The latter is of significant public health 30 importance and comprises two ecotypes: the body louse and the head louse. These ecotypes are morpho-31 logically and genetically notably similar; the body louse is responsible for three infectious diseases: 32 Louse-borne epidemic typhus, relapsing fever, and trench fever. Mitochondrial DNA studies have shown 33 that there are three obviously divergent clades of head lice (A, B and C), and only one clade of body lice is 34 shared with head lice (clade A). Each clade has a unique geographic distribution. Lice have been parasit-35 izing humans for millions of years and likely dispersed throughout the World with the human migrations 36 out of Africa, so they can be good markers for studying human evolution. Here, we present an overview of 37 the origin of human lice and their role in vector pathogenic bacteria that caused epidemics, and we 38 review the association between lice clades and human migrations.
Studies of Ancient Lice Reveal Unsuspected Past Migrations of Vectors
American Journal of Tropical Medicine and Hygiene, 2015
Lice are among the oldest parasites of humans representing an excellent marker of the evolution and migration of our species over time. Here, we analyzed by real-time polymerase chain reaction (RT-PCR) developed in this study the mitochondrial DNA of seven ancient head louse eggs found on hair remains recovered from two sites in Israel: 1) five nits dating from Chalcolithic period (4,000 BC) were found in the Cave of the Treasure located at Nahal Mishmar, in the Judean Desert and 2) two nits dating from Early Islamic Period (AD 650-810) were found in Nahal Omer in the Arava Valley (between Dead Sea and Red Sea). Our results suggest that these eggs belonged to people originating from west Africa based on identification of the louse mitochondrial sub-clade specific to that region.
Comptes Rendus Biologies, 2003
In order to investigate human-louse phylogeny, we partially sequenced two nuclear (18S rRNA and EF-1α) and one mitochondrial (COI) genes from 155 Pediculus from different geographical origins. The phylogenetic analysis of 18S rRNA and EF-1α sequences showed that human lice were classified into lice from Sub-Saharan Africa and lice from other areas. In both clusters, head and body lice were clearly grouped into two separate clusters. Our results indicate that the earliest divergence within human pediculidae occurred between African lice and other lice, and the divergence between head and body lice was not the result from a single event. To cite this article: Z.
Of lice and men: The return of the ’comparative parasitology‘ debate
Parasitology Today, 1995
The question of whether or not parasrte phylogeny provrdes information about host relationships ('comparative paravtoiogy> reached a peak in I 957 In a vrgorous debate between Gunther Timmermann and Ernst Mayr. Timmermann argued that parasrtes were assooated with the/r hosts by descent and that this produced congruent host and parasite phylogenles. In contrast Mayr argued that parasites were often associated by colonization and that this led to incongruence between host and parasjte phylogenies. To test these difinng views, Adnan Paterson, Russell Gray and Graham Walk derived a procellarirfirm phylogeny. This tree is here compared with Timmermann's tree based on the relat/onships of feather kce. T\mmerrnann's tree is more srmilar to the seabird phylogeny than would be expected by chance. Thus, support is found for the 'comparat/ve parasitology' approach.
What’s in a name: The taxonomic status of human head and body lice
Molecular Phylogenetics and Evolution, 2008
Human head lice (Anoplura: Pediculidae: Pediculus) are pandemic, parasitizing countless school children worldwide due to the evolution of insecticide resistance, and human body (clothing) lice are responsible for the deaths of millions as a result of vectoring several deadly bacterial pathogens. Despite the obvious impact these lice have had on their human hosts, it is unclear whether head and body lice represent two morphological forms of a single species or two distinct species. To assess the taxonomic status of head and body lice, we provide a synthesis of publicly available molecular data in GenBank, and we compare phylogenetic and population genetic methods using the most diverse geographic and molecular sampling presently available. Our analyses find reticulated networks, gene flow, and a lack of reciprocal monophyly, all of which indicate that head and body lice do not represent genetically distinct evolutionary units. Based on these findings, as well as inconsistencies of morphological, behavioral, and ecological variability between head and body lice, we contend that no known species concept would recognize these louse morphotypes as separate species. We recommend recognizing head and body lice as morphotypes of a single species, Pediculus humanus, until compelling new data and analyses (preferably analyses of fast evolving nuclear markers in a coalescent framework) indicate otherwise.
Annual Review of Entomology, 2004
Current research on human louse biology has focused on the longstanding debate about speciation of head and body lice but using new tools of DNA and enzyme analysis. These studies have indicated that head and body lice from the same geographical zone may be more closely allied than insects inhabiting the same ecological niche in other regions. However, the majority of research over the past decade has involved clinical aspects including transmission, treatment, and the appearance and identification of resistant strains within populations of lice. Despite advances, there is a need for a better understanding of louse biology, as existing therapies fail and lice remain potential vectors of disease for millons of people.
Bacterial pathogens in lice collected from small redents
2021
In 2008-2020, we snap-trapped small mammals in a 7.05 ha flooded meadow near Rusnė island (55°19'26.23"N, 21°20'24.15"E). During the course of the study, the habitat transitioned from a near-natural flooded meadow in 2008-2012 to a mowed and pastured area in 2020 (reed beds remaining only at the very edges), i.e. a reverse succession of the meadow-to-forest was observed. The anthropogenic influence grew mostly after 2018 and was best expressed in 2020. In this area, we recorded 11 small mammal species and trapped 1917 individuals with a total effort of 9466 trap nights. The dominating species were: harvest mouse in 2008, root vole in 2009 and 2012, and striped field mouse in 2010 and 2013-2020. These accounted for 41.4-92.9% of all small mammals (Figure 1). The average relative density of small mammals was 20.25 individuals per 100 trap nights (range 7.56-40.67), with a four-year-long cycle observed, this mainly being dependent on striped field mice. Species richness was 4-9 and the range of Shannon's diversity index 0.46-2.19. Results of changes in the community structure are analysed according to the hypotheses that: (i) community formation, especially changes in the dominant species, were flood-driven, (ii) herbi-, grani-, insecti-and omnivorous species were separated in time (dominant in different years) according to "favoured states" theory, and (iii) changes in the community structure were related to recent anthropogenic activity. The first two of these hypotheses were confirmed by our previous publications. The possibility of virus influence on decreasing abundances of root voles is still unclear.