There was, however, a resurgence of head lice in the 1960s, and the incidence continues to rise. No area in the United States is immune to head lice. An estimated six to 12 million people are affected each year. Children between the ages of five and 12, girls more often than boys, are affected most often. More infestations occur among children with brown or red hair than among those with black or blond hair.
Some children are prone to repeated infestations, and others are unaffected.
Large families are infested more often than small ones, probably due to proximity rather than socioeconomic status. 2 Head lice are attracted to people with fine hair rather than coarse hair. Except for the African-American population, lice infestation occurs in all races and socioeconomic levels. A low incidence among African-American families is attributed to the shape of the hair shaft. 3 Individuals with good personal hygiene practices are more vulnerable than people with long, dirty hair and scalps.