Body louse

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Body louse

Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Phthiraptera
Suborder: Anoplura
Family: Pediculidae
Genus: Pediculus
Species: P. humanus
Binomial name
Pediculus humanus
L., 1758
Trinomial name
Pediculus humanus corporis
de Geer, 1778

The body louse (Pediculus humanus corpois[1]) is a louse which infests humans. The condition of being infested with head lice, body lice, or pubic lice is known as Pediculosis.

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[edit] Origins

Genetic analysis suggests that the human body louse may have originated about 107,000 years ago, with the ancestor of all human lice emerging about 770,000 years ago.[2]

[edit] Entomology and pathology

Pediculus humanus corporis (the body louse) is indistinguishable in appearance from Pediculus humanus capitis (the head louse) and under laboratory conditions they will interbreed. In their natural state, however, the two subspecies do not interbreed and occupy different habitats. In particular, body lice have evolved to attach their eggs to clothes, whereas head lice attach their eggs to the base of hairs.

Body lice are a nuisance in themselves and cause intense itching. They are however, also vectors (transmitters) of other diseases such as epidemic typhus and louse-borne relapsing fever.

[edit] Treatment

Delousing can be practically achieved by boiling all clothes and bed clothes.[3] In fact, a temperature of 130° F or 55° C for 5 minutes will kill most of the adults and prevent eggs from hatching.[4] Where this is not practical or possible, powder dusting with 10% DDT, 1% malathion or 1% permethrin is also effective.[3] If insecticide is not available, louse-infested clothes and bedding should be burnt on an open fire.

Medication is usually not necessary, as the problem normally goes away with daily bathing and wearing of clean clothes.[4]

Oral ivermectin at a dose of 12mg on days 0, 7 and 14 has been used in a small trial of 33 people in Marseilles, but did not result in complete eradication, although there was a significant fall in the number of parasites and proportion of people infected.[5] At the moment, ivermectin cannot be routinely recommended for the treatment of body lice.

[edit] See also

[edit] References

  1. ^ 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 edition, London: Edward Arnold, 5-23. 
  2. ^ Stoneking, Mark. Erratum: Molecular Evolution of Pediculus humanus and the Origin of Clothing. Retrieved on 2008-03-24.
  3. ^ a b Raoult D, Roux V (1999). "The body louse as a vector of reemerging human diseases". Clin Infect Dis 29: 888–911. doi:10.1086/520454. 
  4. ^ a b Page on website of CIGNA
  5. ^ Foucault C, Ranque S, Badiaga S, et al. (2006). "Oral ivermectin in the treatment of body lice". J Infect Dis 193 (3): 474–6. doi:10.1086/499279.