The number of cases of human louse infestations (or pediculosis) has increased worldwide since the mid-1960s, reaching hundreds of millions annually. It is estimated between 1 and 20% of specific groups in Europe are infected. Despite improvements in medical treatment and prevention of human diseases during the 20th century,<unk>  louse infestation remains stubbornly prevalent. In 1997, 80% of American elementary schools reported at least one outbreak of<unk> .<unk>  infestation during that same period was more prevalent than chickenpox. About 6–12 million children between the ages of 3 and 11 are treated annually for<unk> <unk>  in the United States alone. High levels of louse infestations have also been reported from all over the world, including Israel, Denmark, Sweden, U.K., France, and Australia. The United Kingdom's National Health Service report that<unk>  have no preference for any type of hair be it clean, dirty, or short. The number of children per family, the sharing of beds and closets, hair washing habits, local customs and social contacts, healthcare in a particular area (e.g. school), and socioeconomic status were found to be factors in<unk>  louse infestation in Iran. Other studies found no relationship between frequency of brushing or shampooing. The California Department of Public Health indicates that chronic<unk>  may be a sign of socioeconomic or family problems. Children between 4 and 13 years of age are the most frequently infested group. In the U.S., African-American children have lower rates of infestation.<unk> <unk>  (Pediculus humanus capitis) infestation is most frequent on children aged 3–10 and their families. Females get<unk> <unk>  twice as often as males, and infestation in persons of Afro-Caribbean or other black descent is rare because of hair consistency. But these children may have nits that hatch and the live<unk>  could be transferred by<unk>  contact to other children.
Head lice infestation
Cat bite
Spider bite
Centipede bite
Onychomadesis
Dental plaque
Dog bite
Tick infestation