Human Lice (Anoplura: Pediculidae), Their Detection And Control

Lice, particularly head lice, are becoming a common problem once again, In Florida, the problem of head louse control has arisen in several communities, Millions of American school children may have head lice sometime this year, probably more than at any time in the past 20 years. The increasing incidence of louse infestations throughout the United States affects people on all social and economic levels. Before World War II, head lice were fairly common in the United States, body and crab lice much less so, except among the “less respectable” segments of the population, After World War II and the emergence of DDT as a louse control agent, outbreaks of lice were much less common, Now lice again are intruding into the environment of the average American, Lice or their eggs are easily transmitted from person to person on shared hats, coats, scarves, combs, brushes, towels, bedding, upholstered seats in public places, and by personal contact, Head lice are most prevalent among children, whereas body and pubic (crab) lice are more frequently encountered among young adults and middle-aged persons. When one becomes infested with lice, it is likely that the entire family will become infested, Human louse infestation, called pediculosis, can spread rapidly and may reach epidemic proportions if left unchecked, In a group of people, such factors as age, race (blacks rarely are infested with head lice (Slonka et al, 1975)), sex, crowding at home, family size, method of closeting clothes, and socioeconomic status influence the course and distribution of the disease, The length of the hair does not appear to be a significant factor.

Three types of lice infest humans–body lice (Pediculus humanus humanus Linnaeus, also known as Pediculus humanus corporis), head lice (Pediculus humanus capitis De Geer) (fig. 1), and crab lice or pubic lice (Pthirus pubis (Linnaeus)) (fig. 2). Head lice and body lice are morphologically indistinguishable. Head lice and pubic lice are highly dependent upon human body warmth and will die if separated from their host for 24 hours, Body lice are more hardy since they live on clothing and can survive if separated from human contact for up to a week without feeding.