Unlike head lice and pubic lice, body lice live in clothing and sheets and are usually best eradicated by cleaning the patient's environment (boiling clothing and bedding, or dusting with pediculicides). When these measures failed to control body lice in a homeless shelter, French researchers tried ivermectin.
Thirty-three shelter residents received three weekly doses of ivermectin. Before treatment, 28 were louse-infested, and investigators counted a total of 1898 live lice on the subjects' underwear (including T-shirts) and socks. At day 7, only 18 subjects were infested, and the communal louse count was down to 261 (of which 193 appeared dead). By day 14, five subjects were infested, and the louse count was 15 (9 dead). By day 45 (one month after treatment ended), 17 subjects were again infested, and the louse count was up to 497 (all alive). The assumption was that reinfestation had occurred from the environment.
Ivermectin appears efficacious for eradication of body lice. It is a particularly appealing option for settings like hospitals, in which reinfestation is unlikely to occur.
Reference:
Foucault C et al. Oral ivermectin in the treatment of body lice. J Infect Dis 2006 Feb 1; 193:474-6.