Head louse

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Head louse
Male human head louse.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Psocodea
Family: Pediculidae
Genus: Pediculus
Species:
P. humanus
Subspecies:
P. h. capitis
Trinomial name
Pediculus humanus capitis
De Geer, 1767
Synonyms

Pediculus capitis(De Geer, 1767)

Pediculus humanus capitis by Des Helmore PHTH Pediculidae Pediculus humanus capitis.png
Pediculus humanus capitis by Des Helmore

The head louse (Pediculus humanus capitis) is an obligate ectoparasite of humans. [1] Head lice are wingless insects that spend their entire lives on the human scalp and feed exclusively on human blood. [1] Humans are the only known hosts of this specific parasite, while chimpanzees and bonobos host a closely related species, Pediculus schaeffi. Other species of lice infest most orders of mammals and all orders of birds.

Contents

Lice differ from other hematophagic ectoparasites such as fleas in spending their entire lifecycle on a host. [2] Head lice cannot fly, and their short, stumpy legs render them incapable of jumping, or even walking efficiently on flat surfaces. [2]

The non-disease-carrying head louse differs from the related disease-carrying body louse (Pediculus humanus humanus) in preferring to attach eggs to scalp hair rather than to clothing. The two subspecies are morphologically almost identical, but do not normally interbreed. From genetic studies, they are thought to have diverged as subspecies about 30,000–110,000 years ago, when many humans began to wear a significant amount of clothing. [3] [4] However, the degree of separation is contentious as they can produce fertile offspring in a laboratory. [5]

A much more distantly related species of hair-clinging louse, the pubic or crab louse (Pthirus pubis), also infests humans. It is morphologically different from the other two species and is much closer in appearance to the lice which infest other primates. [6] Louse infestation of the body is known as pediculosis, pediculosis capitis for head lice, pediculosis corporis for body lice, and phthiriasis for pubic lice. [7]

Adult morphology

Head louse crawling on a hairbrush

Like other insects of the suborder Anoplura, adult head lice are small (2.5–3 mm long), dorsoventrally flattened (see anatomical terms of location), and wingless. [8] The thoracic segments are fused, but otherwise distinct from the head and abdomen, the latter being composed of seven visible segments. [9] Head lice are grey in general, but their precise color varies according to the environment in which they were raised. [9] After feeding, consumed blood causes the louse body to take on a reddish color. [9]

Male head louse, adult Fig. 1. Male of head louse.jpg
Male head louse, adult
Female head louse, adult Pediculus humanus var capitis.jpg
Female head louse, adult

One pair of antennae, each with five segments, protrudes from the insect's head. Head lice also have one pair of eyes. Eyes are present in all species within the Pediculidae family, but are reduced or absent in most other members of the Anoplura suborder. [8] Like other members of the Anoplura, head louse mouthparts are highly adapted for piercing the skin and sucking blood. [8] These mouth parts are retracted into the insect's head except during feeding. [9] [10]

Thorax

Head louse gripping a human hair Head louse on human hair.jpg
Head louse gripping a human hair

Six legs project from the fused segments of the thorax. [9] As is typical in the Anoplura, these legs are short and terminate with a single claw and opposing "thumb". [9] Between its claw and thumb, the louse grasps the hair of its host. [9] With their short legs and large claws, lice are well adapted to clinging to the hair of their host. These adaptations leave them incapable of jumping, or even walking efficiently on flat surfaces. Lice can climb up strands of hair very quickly, allowing them to move quickly and reach another host. [2]

Abdomen

Seven segments of the louse abdomen are visible. [9] The first six segments each have a pair of spiracles through which the insect breathes. [9] The last segment contains the anus and (separately) the genitalia. [9]

Sex differences

In male lice, the front two legs are slightly larger than the other four. This specialized pair of legs are used for holding the female during copulation. Males are slightly smaller than females and are characterized by a pointed end of the abdomen and a well-developed genital apparatus visible inside the abdomen. Females are characterized by two gonopods in the shape of a W at the end of their abdomens.

Eggs and nits

Head louse egg (nit) attached to hair shaft of host Head louse egg 2.jpg
Head louse egg (nit) attached to hair shaft of host

Like most insects, head lice are oviparous. Females lay about three or four eggs per day. Louse eggs (also known as nits), are attached near the base of a host hair shaft. [11] [12] Eggs are usually laid on the base of the hair, 3–5 mm off the scalp surface. [11] [12] In warm climates, and especially the tropics, eggs may be laid 6 inches (15 cm) or more down the hair shaft. [13]

To attach an egg, the adult female secretes a glue from her reproductive organ. This glue quickly hardens into a "nit sheath" that covers the hair shaft and large parts of the egg except for the operculum, a cap through which the embryo breathes. [12] The glue was previously thought to be chitin-based, but more recent studies have shown it to be made of proteins similar to hair keratin. [12]

Each egg is oval-shaped and about 0.8 mm in length. [12] They are bright, transparent, and tan to coffee-colored so long as they contain an embryo, but appear white after hatching. [12] [13] Head lice hatch typically six to nine days after oviposition. [11] [14]

After hatching, the louse nymph leaves behind its egg shell, still attached to the hair shaft. The empty egg shell remains in place until physically removed by abrasion or the host, or until it slowly disintegrates, which may take six or more months. [14]

Empty shells are matte, collapsed and white in color. The term nit may include any of the following: [15]

Of these three, only eggs containing viable embryos have the potential to infest or reinfest a host. [16] However, a no nit policy is a common public health measure to prevent transmission of lice. Some authors have therefore restricted the definition of nit to describe only a hatched or nonviable egg:

Louse hatching Anoplura hatching.jpg
Louse hatching

In many languages, the terms used for the hatched eggs, which were obvious for all to see, have subsequently become applied to the embryonated eggs that are difficult to detect. Thus, the term "nit" in English is often used for both. However, in recent years, my colleagues and I have felt the need for some simple means of distinguishing between the two without laborious qualification. We have, therefore, come to reserve the term "nit" for the hatched and empty egg shell and refer to the developing embryonated egg as an "egg".

— Ian F. Burgess (1995) [14]

The empty eggshell, termed a nit...

— J. W. Maunder (1983) [2]

...nits (dead eggs or empty egg cases)...

— Kosta Y. Mumcuoglu and others (2006) [17]

Others have retained the broad definition, while simultaneously attempting to clarify its relevance to infestation:

In the United States the term "nit" refers to any egg regardless of its viability.

— Terri Lynn Meinking (1999) [13]

Because nits are simply egg casings that can contain a developing embryo or be empty shells, not all nits are infective.

— L. Keoki Williams and others (2001) [11]

Head lice eggs (nits) are brown or white (empty shells) and attached to the hair

— NHS (2018) [18]

In British and Irish slang the term "nit" is often used, across different age groups, to refer to the head lice themselves. [19] [20] [21] [22]

Development and nymphs

Development of Pediculus humanus humanus (body lice), which is similar to that of head lice (Pediculus humanus capitis) Pediculus humanus development.jpg
Development of Pediculus humanus humanus (body lice), which is similar to that of head lice (Pediculus humanus capitis)

Head lice, like other insects of the order Phthiraptera, are hemimetabolous. [1] [10] Newly hatched nymphs will moult three times before reaching the sexually mature adult stage. [1] Thus, mobile head lice populations may contain eggs, nits, three nymphal instars, and the adults (male and female) (imago). [1] Metamorphosis during head louse development is subtle. The only visible differences between different instars and the adult, other than size, is the relative length of the abdomen, which increases with each molt, [1] as well as the existence of reproductive organs in the adults. Aside from reproduction, nymph behavior is similar to the adult. Like adults, nymphs feed also only on human blood (hematophagia), and cannot survive long away from a host. [1] Outside their hosts lice cannot survive more than 24 hrs. [23] The time required for head lice to complete their nymph development to the imago lasts for 12–15 days. [1]

Nymph mortality in captivity is about 38%, especially within the first two days of life. [1] In the wild, mortality may instead be highest in the third instar. [1] Nymph hazards are numerous. Failure to completely hatch from the egg is invariably fatal. [1] Death during molting can also occur, although it is reportedly uncommon. [1] During feeding, the nymph gut can rupture, dispersing the host's blood throughout the insect body. This results in death within a day or two. [1] Whether the high mortality recorded under experimental conditions is representative of conditions in the wild is unclear. [1]

Reproduction and lifespan

Copulation in Pediculus humanus humanus (Pediculus humanus capitis is similar), female is on top, with the male below. Dilation of the female's vagina has already occurred, and the male's dilator rests against his back (dorsal surface), out of the way. The male vesica, which contains the penis proper (not seen), is fully inserted into the vagina. Note the male's attachment with his specialized claws on the first leg pair to the specialized notch on the female's third leg pair. Nuttall 1917 f11.gif
Copulation in Pediculus humanus humanus (Pediculus humanus capitis is similar), female is on top, with the male below. Dilation of the female's vagina has already occurred, and the male's dilator rests against his back (dorsal surface), out of the way. The male vesica, which contains the penis proper (not seen), is fully inserted into the vagina. Note the male's attachment with his specialized claws on the first leg pair to the specialized notch on the female's third leg pair.

Head lice reproduce sexually, and copulation is necessary for the female to produce fertile eggs. Parthenogenesis, the production of viable offspring by virgin females, does not occur in Pediculus humanus. [1] Pairing can begin within the first 10 hours of adult life. [1] After 24 hours, adult lice copulate frequently, with mating occurring during any period of the night or day. [1] [24] Mating attachment frequently lasts more than an hour. [24] Young males can successfully pair with older females, and vice versa. [1]

Experiments with P. h. humanus (body lice) emphasize the attendant hazards of lice copulation. A single young female confined with six or more males will die in a few days, having laid very few eggs. [1] Similarly, death of a virgin female was reported after admitting a male to her confinement. [24] The female laid only one egg after mating, and her entire body was tinged with red—a condition attributed to rupture of the alimentary canal during the sexual act. [24] Old females frequently die following, if not during, copulation. [24] During its lifespan of 4 weeks a female louse lays 50-150 eggs. Eggs hatch within 6–9 days, each nymphal stage last for 4–5 days and accordingly the period from egg to adults lasts for 18–24 days. Adult lice live for an additional 3–4 weeks. [25]

Factors affecting infestation

The number of children per family, the sharing of beds and closets, hair washing habits, local customs and social contacts, healthcare in a particular area (e.g. school), and socioeconomic status were found to be significant factors in head louse infestation. Girls are two to four times more frequently infested than boys. Children between 4 and 14 years of age are the most frequently infested group. [26]

Behaviour

Feeding

All stages except eggs are blood-feeders and bite the skin four to five times daily to feed. They inject saliva which contains an anticoagulant and suck blood. The digested blood is excreted as dark red frass. [27]

Position on host

Although any part of the scalp may be colonized, lice favor the nape of the neck and the area behind the ears, where the eggs are usually laid. Head lice are repelled by light and move towards shadows or dark-coloured objects in their vicinity. [24] [28]

Transmission

Lice have no wings or powerful legs for jumping, so they use the claws on their legs to move from hair to hair. [27] Normally, head lice infest a new host only by close contact between individuals, making social contacts among children and parent-child interactions more likely routes of infestation than shared combs, hats, brushes, towels, clothing, beds, or closets. Head-to-head contact is by far the most common route of lice transmission. [29]

Distribution

About 6–12 million people, mainly children, are treated annually for head lice in the United States alone. In the UK, it is estimated that two thirds of children will experience at least one case of head lice before leaving primary school. [30] High levels of louse infestations have also been reported from all over the world, including Australia, Denmark, France, Ireland, Israel, and Sweden. [16] [31]

Archaeogenetics

Analysis of the DNA of lice found on Peruvian mummies may indicate that some diseases (such as typhus) may have passed from the New World to the Old World, instead of the other way around. [32] [33]

Genome

The sequencing of the genome of the body louse was first proposed in the mid-2000s [34] and the annotated genome was published in 2010. [35] An analysis of the body and head louse transcriptomes revealed these two organisms are extremely similar genetically. [36]

Unlike other bilateral animals, the 37 mitochondrial genes of human lice are not on a single circular chromosome but extensively fragmented. For the head louse, and the body louse, they are on 20 minichromosomes, for the pubic louse 14 minichromosomes and the chimpanzee louse,18 minichromosomes. [37]

Mitochondrial clades

Human lice are divided into three deeply divergent mitochondrial clades known as A, B, and C. [38] [39] Three subclades have been identified, D (a sister clade of A), E (a sister clade of C), and F (a sister clade of B). [40] [41] [42]

Clade A

Clade D (sister of clade A)

Clade B

Clade F (sister of clade B)

Clade C

Clade E (sister of clade C)

See also

Related Research Articles

<span class="mw-page-title-main">Louse</span> Order of insects

Louse is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a result of developments in phylogenetic research.

<i>Mallophaga</i> Suborder of lice

The Mallophaga are a possibly paraphyletic section of lice, known as chewing lice, biting lice, or bird lice, containing more than 3000 species. These lice are external parasites that feed mainly on birds, although some species also feed on mammals. They infest both domestic and wild mammals and birds, and cause considerable irritation to their hosts. They have paurometabolis or incomplete metamorphosis.

<span class="mw-page-title-main">Sucking louse</span> Suborder of insects

Sucking lice have around 500 species and represent the smaller of the two traditional superfamilies of lice. As opposed to the paraphyletic chewing lice, which are now divided among three suborders, the sucking lice are monophyletic.

<span class="mw-page-title-main">Crab louse</span> Species of insect

The crab louse or pubic louse is an insect that is an obligate ectoparasite of humans, feeding exclusively on blood. The crab louse usually is found in the person's pubic hair. Although the louse cannot jump, it can also live in other areas of the body that are covered with coarse hair, such as the perianal area, the entire body, and the eyelashes.

<span class="mw-page-title-main">Pediculosis</span> Medical condition

Pediculosis is an infestation of lice from the sub-order Anoplura, family Pediculidae. Accordingly, the infestation with head lice is named pediculosis capitis, while this with body lice, pediculosis corporis. Although pediculosis in humans may properly refer to lice infestation of any part of the body, the term is sometimes used loosely to refer to pediculosis capitis, the infestation of the human head with the specific head louse.

<span class="mw-page-title-main">Treatment of human lice</span> Medical intervention

The treatment of human lice is the removal of head lice parasites from human hair. It has been debated and studied for centuries. However, the number of cases of human louse infestations has increased worldwide since the mid-1960s, reaching hundreds of millions annually. There is no product or method that assures 100% destruction of the eggs and hatched lice after a single treatment. However, there are a number of treatment modalities that can be employed with varying degrees of success. These methods include chemical treatments, natural products, combs, shaving, hot air, and silicone-based lotions.

<span class="mw-page-title-main">Menoponidae</span> Family of lice

Menoponidae is a monophyletic family of lice in the superfamily of chewing lice, Amblycera, often referred to as the chicken body louse family. They are ectoparasites of a wide range of birds including chickens, which makes them important to understand for veterinary science and for human health. However, Menoponidae are not exclusive to poultry and are common parasites for migratory birds, with more and more species being discovered every year.

<span class="mw-page-title-main">Body louse</span> Subspecies of insect

The body louse or the cootie is a hematophagic ectoparasite louse that infests humans. It is one of three lice which infest humans, the other two being the head louse, and the crab louse or pubic louse.

<span class="mw-page-title-main">Use of DNA in forensic entomology</span>

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<span class="mw-page-title-main">Head lice infestation</span> Medical condition

Head lice infestation, also known as pediculosis capitis, is the infection of the head hair and scalp by the head louse. Itching from lice bites is common. During a person's first infection, the itch may not develop for up to six weeks. If a person is infected again, symptoms may begin much more quickly. The itch may cause problems with sleeping. Generally, however, it is not a serious condition. While head lice appear to spread some other diseases in Africa, they do not appear to do so in Europe or North America.

<span class="mw-page-title-main">Archaeoparasitology</span> Study of parasites in archaeological contexts

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<span class="mw-page-title-main">No nit policy</span> Public health policy

No nit policy is a public health policy implemented by some education authorities to prevent the transmission of head lice infestation. The "no nit" policy requires the sending home and barring of all children who have nits on their hair from controlled settings such as school, summer camp or day care facilities. The CDC, American Academy of Pediatrics (AAP) and the National Association of School Nurses (NASN) advocate that "no-nit" policies should be discontinued, due in part because nits, the eggs or empty egg shells, are not transmissible and the burden of unnecessary absenteeism to the students, families and communities far outweighs the risks associated with head lice. Proponents of the no-nit policy counter that only a consistently nit-free child can be reliably shown to be infestation-free. That is, the presence of nits serves as a proxy for infestation status. Proponents argue that such a proxy is necessary because lice screening is prone to false negative conclusions.

<span class="mw-page-title-main">Salmon louse</span> Parasitic crustacean of fish

The salmon louse is a species of copepod in the genus Lepeophtheirus. It is a sea louse, a parasite living mostly on salmon, particularly on Pacific and Atlantic salmon and sea trout, but is also sometimes found on the three-spined stickleback. It feeds on the mucus, skin and blood of the fish. Once detached, they can be blown by wind across the surface of the sea, like plankton. When they encounter a suitable marine fish host, they adhere themselves to the skin, fins, or gills of the fish, and feed on the mucus or skin. Sea lice only affect fish and are not harmful to humans.

<span class="mw-page-title-main">Pediculosis corporis</span> Medical condition

Pediculosis corporis or Vagabond's disease is a cutaneous condition caused by body lice that lay their eggs on clothing and to a lesser extent on human hairs.

<span class="mw-page-title-main">Pediculosis pubis</span> Infestation by the pubic louse

Pediculosis pubis is an infestation by the pubic louse, Pthirus pubis, a wingless insect which feeds on blood and lays its eggs (nits) on mainly pubic hair. Less commonly, hair near the anus, armpit, beard, eyebrows, moustache, and eyelashes may be involved. It is usually acquired during sex, but can be spread via bedding, clothing and towels, and is more common in crowded conditions where there is close contact between people.

Lemurpediculus verruculosus is an ectoparasite that is found on Microcebus rufus, a mouse lemur of southeastern Madagascar. It is a type of sucking louse that is found on the external ears of the mouse lemur due to the rich peripheral blood supply and sparse fur. The mouse lemur M. rufus is the only known host to this particular sucking louse, and infestations range from light to fairly heavy on the ears. The exact effect these lice have on the host is largely unknown.

<i>Trichodectes canis</i> Species of louse

Trichodectes canis, also known as canine chewing louse, is a chewing louse found on domesticated dogs and wild canids throughout the world. T. canis is a well-known vector for the dog tapeworm, Dipylidium caninum. T. canis usually does not present any major problems to the host, however, can be very irritating in heavy infestations. In North America and most developed countries, T. canis infestation of domesticated dogs is very uncommon as long as they are properly cared for and healthy. Poorly taken care of dogs are more prone to getting a lice infestation.

<i>Haematopinus suis</i> Species of louse

Haematopinus suis, the hog louse, is one of the largest members of the louse suborder Anoplura, which consists of sucking lice that commonly afflict a number of mammals. H. suis is found almost solely on the skin surface of swine, and takes several blood meals a day from its host. H. suis has large claws that enable it to grasp a hog's hair and move around its body. It is easily seen without magnification, being 5–6 millimetres (0.20–0.24 in) long. H. suis has a long, narrow head and long mouthparts adapted for sucking blood. It is the only louse found on swine. H. suis infestation is relatively rare in the US; a 2004 study found that about 14% of German swine farms had H. suis infestations. Due to the frequency of feeding, infected swine become severely irritated, often rubbing themselves to the point of injuring their skin and displacing body hair. Particularly afflicted hogs may become almost completely bald and, in young hogs, the resulting stress can arrest growth, a cause of concern for farmers.

Bovicola bovis is a cattle-biting louse found all over the world. It is a common pest of cattle of all types and sizes. They are one of many lice in the order Phthiraptera, but are divided from their blood sucking cousins in the sub-order Anoplura by the fact that they feed only by chewing. This makes B. bovis a member of the sub-order Mallophaga.

<i>Pediculus</i> Genus of lice

Pediculus is a genus of sucking lice, the sole genus in the family Pediculidae. Pediculus species are ectoparasites of primates.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Buxton, Patrick A. (1947). "The biology of Pediculus humanus". The Louse; an account of the lice which infest man, their medical importance and control (2nd ed.). London: Edward Arnold. pp. 24–72.
  2. 1 2 3 4 Maunder, J. W. (1983). "The Appreciation of Lice". Proceedings of the Royal Institution of Great Britain. 55: 1–31.
  3. ↑ Kittler R, Kayser M, Stoneking M (August 2003). "Molecular evolution of Pediculus humanus and the origin of clothing". Current Biology. 13 (16): 1414–7. Bibcode:2003CBio...13.1414K. doi: 10.1016/S0960-9822(03)00507-4 . PMID   12932325.
  4. ↑ Stoneking, Mark (29 December 2004). "Erratum: Molecular Evolution of Pediculus humanus and the Origin of Clothing". Current Biology. 14 (24): 2309. doi: 10.1016/j.cub.2004.12.024 .
  5. ↑ Tovar-Corona, Jaime M.; Castillo-Morales, Atahualpa; Chen, Lu; Olds, Brett P.; Clark, John M.; Reynolds, Stuart E.; Pittendrigh, Barry R.; Feil, Edward J.; Urrutia, Araxi O. (2015). "Alternative Splice in Alternative Lice". Molecular Biology and Evolution. 32 (10): 2749–2759. doi:10.1093/molbev/msv151. ISSN   0737-4038. PMC   4576711 . PMID   26169943.
  6. ↑ Buxton, Patrick A. (1947). "The crab louse Phthirus pubis". The Louse; an account of the lice which infest man, their medical importance and control (2nd ed.). London: Edward Arnold. pp. 136–141.
  7. ↑ "pediculosis – Definition from the Merriam-Webster Online Dictionary" . Retrieved 2008-04-23.
  8. 1 2 3 Buxton, Patrick A. (1947). "The Anoplura or Sucking Lice". The Louse; an account of the lice which infest man, their medical importance and control (2nd ed.). London: Edward Arnold. pp. 1–4.
  9. 1 2 3 4 5 6 7 8 9 10 Buxton, Patrick A. (1947). "The Anatomy of Pediculus humanus". The Louse; an account of the lice which infest man, their medical importance and control (2nd ed.). London: Edward Arnold. pp. 5–23.
  10. 1 2 "Lice (Pediculosis)". The Merck Veterinary Manual. Whitehouse Station, NJ USA: Merck & Co. 2008. Retrieved 2008-10-08.
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  13. 1 2 3 Meinking, Terri Lynn (May–June 1999). "Infestations". Current Problems in Dermatology. 11 (3): 75–118. doi: 10.1016/S1040-0486(99)90005-4 .
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  15. ↑ Pollack RJ, Kiszewski AE, Spielman A (August 2000). "Overdiagnosis and consequent mismanagement of head louse infestations in North America". The Pediatric Infectious Disease Journal. 19 (8): 689–93, discussion 694. doi:10.1097/00006454-200008000-00003. PMID   10959734. S2CID   2557006.
  16. 1 2 Burgess, I. F. (2004). "Human lice and their control". Annu. Rev. Entomol. 49: 457–81. doi:10.1146/annurev.ento.49.061802.123253. PMID   14651472.
  17. ↑ Mumcuoglu KY, Meinking TA, Burkhart CN, Burkhart CG (August 2006). "Head louse infestations: the 'no nit' policy and its consequences". International Journal of Dermatology. 45 (8): 891–6. doi:10.1111/j.1365-4632.2006.02827.x. PMID   16911370. S2CID   38910169.
  18. ↑ "Head lice and nits". nhs.uk. 2017-10-19. Retrieved 23 December 2018.
  19. ↑ "Head lice: How to spot nits in hair and what to do about them". News Shopper. 13 September 2018. Retrieved 23 December 2018.
  20. ↑ "Nit treatments are like diets. The truth is, nothing works". The Guardian. 21 June 2018. Retrieved 23 December 2018.
  21. ↑ "How to get rid of head lice". 25 December 2021. Archived from the original on 25 December 2021. Retrieved 5 August 2021.
  22. ↑ "Back to school herbalism — natural ways to nuke nits". Irish Examiner. 1 September 2018. Archived from the original on 23 December 2018. Retrieved 23 December 2018.
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  24. 1 2 3 4 5 6 Bacot, A. (1917). "Contributions to the bionomics of Pediculus humanus (vestimenti) and Pediculus capitis". Parasitology. 9 (2): 228–258. doi:10.1017/S0031182000006065. S2CID   86846228.
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  26. ↑ Mumcuoglu KY (May 2006). "Effective treatment of head louse with pediculicides". Journal of Drugs in Dermatology. 5 (5): 451–2. PMID   16703782.
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  32. ↑ Anderson, Andrea (February 8, 2008). "DNA from Peruvian Mummy Lice Reveals History". GenomeWeb Daily News. GenomeWeb LLC. Retrieved August 31, 2014.
  33. 1 2 Amanzougaghene N, Mumcuoglu KY, Fenollar F, Alfi S, Yesilyurt G, Raoult D, Mediannikov O (2016). "High Ancient Genetic Diversity of Human Lice, Pediculus humanus, from Israel Reveals New Insights into the Origin of Clade B Lice". PLOS ONE. 14 (2016 Oct 14, 11(10):e01646595): e0164659. Bibcode:2016PLoSO..1164659A. doi: 10.1371/journal.pone.0164659 . PMC   5065229 . PMID   27741281.
  34. ↑ Pittendrigh BR, Clark JM, Johnston JS, Lee SH, Romero-Severson J, Dasch GA (November 2006). "Sequencing of a new target genome: the Pediculus humanus humanus (Phthiraptera: Pediculidae) genome project". Journal of Medical Entomology. 43 (6): 1103–11. doi:10.1603/0022-2585(2006)43[1103:SOANTG]2.0.CO;2 (inactive 2024-11-22). PMID   17162941. S2CID   25046936.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
  35. ↑ Kirkness EF, Haas BJ, Sun W, et al. (July 2013). "Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle". Proceedings of the National Academy of Sciences of the United States of America. 107 (27): 12168–73. Bibcode:2010PNAS..10712168K. doi: 10.1073/pnas.1003379107 . PMC   2901460 . PMID   20566863.
  36. ↑ Olds BP, Coates BS, Steele LD, et al. (April 2012). "Comparison of the transcriptional profiles of head and body lice". Insect Molecular Biology. 21 (2): 257–68. doi:10.1111/j.1365-2583.2012.01132.x. PMID   22404397. S2CID   175421.
  37. ↑ Herd, Kate E.; Barker, Stephen C.; Shao, Renfu (2015). "The mitochondrial genome of the chimpanzee louse, Pediculus schaeffi: insights into the process of mitochondrial genome fragmentation in the blood-sucking lice of great apes". BMC Genomics. 16 (1): 661. doi: 10.1186/s12864-015-1843-3 . ISSN   1471-2164. PMC   4557858 . PMID   26335315.
  38. ↑ Morand, Serge; Krasnov, Boris R.; Littlewood, D. Timothy J. (26 February 2015). Parasite Diversity and Diversification: Evolutionary Ecology Meets Phylogenetics. Cambridge University Press. p. 208. ISBN   978-1-316-23993-3 . Retrieved 30 December 2017.
  39. ↑ Knapp, Michael; Boutellis, Amina; Drali, Rezak; Rivera, Mario A.; Mumcuoglu, Kosta Y.; Raoult, Didier (2013). "Evidence of Sympatry of Clade A and Clade B Head Lice in a Pre-Columbian Chilean Mummy from Camarones". PLOS ONE. 8 (10): e76818. Bibcode:2013PLoSO...876818B. doi: 10.1371/journal.pone.0076818 . ISSN   1932-6203. PMC   3813697 . PMID   24204678.
  40. ↑ Gao, Feng; Amanzougaghene, Nadia; Mumcuoglu, Kosta Y.; Fenollar, Florence; Alfi, Shir; Yesilyurt, Gonca; Raoult, Didier; Mediannikov, Oleg (2016). "High Ancient Genetic Diversity of Human Lice, Pediculus humanus, from Israel Reveals New Insights into the Origin of Clade B Lice". PLOS ONE. 11 (10): e0164659. Bibcode:2016PLoSO..1164659A. doi: 10.1371/journal.pone.0164659 . ISSN   1932-6203. PMC   5065229 . PMID   27741281.
  41. ↑ Liao, Chien-Wei; Cheng, Po-Ching; Chuang, Ting-Wu; Chiu, Kuan-Chih; Chiang, I-Chen; Kuo, Juo-Han; Tu, Yun-Hung; Fan, Yu-Min; Jiang, Hai-Tao; Fan, Chia-Kwung (2017). "Prevalence of Pediculus capitis in schoolchildren in Battambang, Cambodia". Journal of Microbiology, Immunology and Infection. 52 (4): 585–591. doi: 10.1016/j.jmii.2017.09.003 . ISSN   1684-1182. PMID   29150362.
  42. ↑ Amanzougaghene, Nadia; Fenollar, Florence; Davoust, Bernard; Djossou, Félix; Ashfaq, Muhammad; Bitam, Idir; Raoult, Didier; Mediannikov, Oleg (June 2019). "Mitochondrial diversity and phylogeographic analysis of Pediculus humanus reveals a new Amazonian clade "F"". Infection, Genetics and Evolution. 70: 1–8. Bibcode:2019InfGE..70....1A. doi: 10.1016/j.meegid.2019.02.006 . PMID   30769089. S2CID   73476298.
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