louse, human

Male human louse (Pediculus humanus; magnified about 15 …

(credit: William E. Ferguson)

Any of three types of sucking louse that infest humans. The body louse (mainly Pediculus humanus humanus, also called human louse or cootie) and head louse (P. h. capitis) are spread by person-to-person contact and through shared clothing, bedding, combs, and other personal items. Body lice carry the organisms that cause relapsing fever, trench fever, and typhus. Head lice may cause impetigo. Both are readily spread under conditions of overcrowding, especially among children. The crab louse, or pubic louse (Phthirus pubis) infests primarily the pubic region and occasionally other hairy regions. Its first pair of legs is smaller than the other two pairs, making it look like a crab. Crab lice are transmitted primarily through sexual intercourse. Lice infestations can be quickly cured with shampoos, soaps, and lotions containing benzene hexachloride, along with the thorough washing of bedding and clothing.