@article {46045, title = {Evidence from mitochondrial DNA that head lice and body lice of humans (Phthiraptera: Pediculidae) are conspecific}, journal = {Journal of Medical Entomology}, volume = {39}, year = {2002}, month = {2002}, pages = {662 - 666}, abstract = {

The specific status of the head and body lice of humans has been debated for more than 200 yr. To clarify the specific status of head and body lice, we sequenced 524 base pairs (bp) of the cytochrome oxidase I (COI) gene of 28 head and 28 body lice from nine countries. Ten haplotypes that differed by 1-5 bp at 11 nucleotide positions were identified. A phylogeny of these sequences indicates that these head and body lice are not from reciprocally monophyletic lineages. Indeed, head and body lice share three of the 10 haplotypes we found. F(ST) values and exact tests of haplotype frequencies showed significant differences between head and body lice. However, the same tests also showed significant differences among lice from different countries. Indeed, more of the variation in haplotype frequencies was explained by differences among lice from different countries than by differences between head and body lice. Our results indicate the following: (1) head and body lice do not represent reciprocally monophyletic lineages and are conspecific; (2) gene flow among populations of lice from different countries is limited; and (3) frequencies of COI haplotypes can be used to study maternal gene flow among populations of head and body lice and thus transmission of lice among their human hosts.

}, keywords = {animals, dna, humans, Pediculus}, isbn = {0022-2585}, url = {https://phthiraptera.myspecies.info/sites/phthiraptera.info/files/44856.pdf}, author = {Leo,Natalie P. and Campbell,N. J. and Yang,X. and Kosta Y. Mumcuoglu and Stephen C. Barker} } @article {46032, title = {Intragenomic variation in ITS2 rDNA in the louse of humans, Pediculus humanus: ITS2 is not a suitable marker for population studies in this species}, journal = {Insect Molecular Biology}, volume = {11}, year = {2002}, month = {2002}, pages = {651 - 657}, abstract = {

The two internal transcribed spacers (ITS) of ribosomal DNA are often used as markers of populations of insects. We studied the ITS2 of the head lice and body lice of humans, to determine whether this gene is a suitable marker of populations of these insects. ITS2 sequences were amplified by PCR from lice from four different countries: Australia, China, Japan and the USA. Direct cycle-sequencing of some of these PCR products gave equivocal nucleotide chromatograms. This indicated that some lice had more than one ITS2 sequence, so we cloned PCR products from these lice. Temperature gradient gel electrophoresis (TGGE) revealed that 50 of the 67 clones we screened had different nucleotide sequences. All lice had several ITS2 types, including those with unequivocal chromatograms. A phylogenetic tree of 15 different ITS2 sequences showed that the sequences from individual lice were not monophyletic. We conclude that the ITS2 is not a useful marker of populations for Pediculus humanus.

}, keywords = {animals, Australia, Base Sequence, China, dna, geography, humans, Introns, Japan, Lice Infestations/parasitology, Molecular Sequence Data, Pediculus, Phylogeny, polymerase, Research Support, Non-U.S. Gov{\textquoteright}t, sequence, U.S.A., variation}, url = {http://www.phthiraptera.info/sites/phthiraptera.info/files/44841.pdf}, author = {Leo,Natalie P. and Stephen C. Barker} } @article {46000, title = {Potential role of head lice, Pediculus humanus capitis, as vectors of Rickettsia prowazekii}, journal = {Parasitology research}, volume = {90}, year = {2003}, month = {2003}, pages = {209 - 211}, abstract = {

Since the pioneering work of Charles Nicolle in 1909 [see Gross (1996) Proc Natl Acad Sci USA 93:10539-10540] most medical officers and scientists have assumed that body lice are the sole vectors of Rickettsia prowazekii, the aetiological agent of louse-borne epidemic typhus (LBET). Here we review the evidence for the axiom that head lice are not involved in epidemics of LBET. Laboratory experiments demonstrate the ability of head lice to transmit R. prowazekii, but evidence for this in the field has not been reported. However, the assumption that head lice do not transmit R. prowazekii has meant that head lice have not been examined for R. prowazekii during epidemics of LBET. The strong association between obvious (high) infestations of body lice and LBET has contributed to this perception, but this association does not preclude head lice as vectors of R. prowazekii. Indeed, where the prevalence and intensity of body louse infections may be high (e.g. during epidemics of LBET), the prevalence and intensity of head louse infestations is generally high as well. This review of the epidemiology of head louse and body louse infestations, and of LBET, indicates that head lice are potential vectors of R. prowazekii in the field. Simple observations in the field would reveal whether or not head lice are natural vectors of this major human pathogen.

}, keywords = {animals, humans, Insect vectors, Lice Infestations/epidemiology, Pediculus, Rickettsia prowazekii/physiology, typhus}, isbn = {0932-0113}, doi = {10.1007/s00436-003-0842-5}, url = {http://link.springer.com/article/10.1007\%2Fs00436-003-0842-5}, author = {Robinson,D. and Leo,Natalie P. and Prociv,P. and Stephen C. Barker} } @article {45877, title = {The head and body lice of humans are genetically distinct (Insecta: Phthiraptera, Pediculidae): evidence from double infestations}, journal = {Heredity}, volume = {95}, year = {2005}, month = {2005}, pages = {34 - 40}, abstract = {

Little is known about the population genetics of the louse infestations of humans. We used microsatellite DNA to study 11 double infestations, that is, hosts infested with head lice and body lice simultaneously. We tested for population structure on a host, and for population structure among seven hosts that shared sleeping quarters. We also sought evidence of migration among louse populations. Our results showed that: (i) the head and body lice on these individual hosts were two genetically distinct populations; (ii) each host had their own populations of head and body lice that were genetically distinct to those on other hosts; and (iii) lice had migrated from head to head, and from body to body, but not between heads and bodies. Our results indicate that head and body lice are separate species.

}, keywords = {animals, dna, head, humans, lice infestations, Microsatellite Repeats/genetics, movement, Pediculus, polymerase}, isbn = {0018-067X}, url = {http://www.phthiraptera.info/sites/phthiraptera.info/files/44646.pdf}, author = {Leo,Natalie P. and Hughes,J. M. and Yang,X. and Shree Kanta S. Poudel and Brogdon,William G. and Stephen C. Barker} } @article {45689, title = {Unravelling the evolution of the head lice and body lice of humans}, journal = {Parasitological Research}, volume = {98}, year = {2005}, month = {2005}, pages = {44 - 47}, keywords = {capitis, humanus, Pediculus, Phthiraptera, Phylogeny, RNA, ssr}, url = {http://www.phthiraptera.info/sites/phthiraptera.info/files/9200.pdf}, author = {Leo,Natalie P. and Stephen C. Barker} }