Plural of louse, parasitic insects that occur in three varieties: head lice, pubic lice, and body lice. Body lice (Pediculus corporis) are associated with two louse-borne diseases of great public health importance, louse-borne epidemic typhus and relapsing fever, both of which were common for centuries, associated with overcrowding, wearing dirty clothes, and lack of access to bathing, washing, and opportunities to put on clean clothes, typically conditions associated with warfare, displacement, poverty, and refugee movement. Head lice (Pediculus capitis) commonly infect school children, laying eggs, known as nits, that attach to hair and require combing with a fine-tooth comb to detach them. Children infect one another when the lice move from one child's head to another. Head lice often occur in epidemic form in schools. Pubic lice (Pthirus pubis, “crabs”) are anatomically different, infest pubic hair almost exclusively, and spread from person to person during sexual intercourse. Head lice and pubic lice, although transmitted person to person by direct contact, do not carry or transmit disease.
Subjects: Public Health and Epidemiology.