Finally, be aware that the head louse is only one of three lice species found in humans. The other two species require slightly different approaches in patient care. The body louse, Pediculus humanus corporis, is a vector of epidemic typhus, trench fever, and relapsing fever. This parasite is associated with poverty and poor hygiene, and infestations are common among homeless and lower income people. It survives because the victim usually wears only one set of clothing.
Transmission is conducted by contact with infested clothing or bedding.
The third species is the pubic louse, Phthirus pubis, commonly known as the crab louse. This species also is nondiscriminatory. It will infest anyone of any race or socioeconomic status, and infestation is most common in sexually active adults. It is uncertain whether transmission of this type of louse occurs from bedding or clothing. Nosocomial transmission is considered to be very unlikely.