Disease caused by lice? - briefly
Body lice transmit epidemic typhus (Rickettsia prowazekii), trench fever (Bartonella quintana), and relapsing fever, while head lice are not known to spread serious disease.
Disease caused by lice? - in detail
Lice are obligate ectoparasites that feed on human blood or skin debris. Three species affect humans: head louse (Pediculus humanus capitis), body louse (Pediculus humanus humanus), and crab louse (Pthirus pubis). Only the body louse is recognized as a vector for serious bacterial infections.
Diseases transmitted by the body louse include:
- Epidemic typhus, caused by Rickettsia prowazekii. Presents with abrupt fever, headache, rash that begins on the trunk and spreads outward, and potential complications such as pneumonitis or encephalitis. Untreated mortality can exceed 10 %.
- Trench fever, caused by Bartonella quintana. Characterized by recurrent fever spikes, severe leg pain, and a chronic relapsing course. Historically linked to World War I trench conditions; modern cases occur among homeless populations.
- Louse‑borne relapsing fever, caused by Borrelia recurrentis. Manifests as alternating episodes of high fever, chills, and headache, with possible meningitis or myocarditis if untreated.
Head lice infestations rarely result in systemic illness. Primary consequences are intense itching, excoriation, and secondary bacterial infection of the scalp. Crab lice cause pruritus in the genital area but are not associated with systemic disease.
Clinical diagnosis of lice infestation relies on visual detection of live insects or viable nits attached to hair shafts or clothing seams. Laboratory confirmation of louse‑borne infections requires serology, polymerase chain reaction, or culture of the implicated pathogen.
Effective management includes:
- Mechanical removal of lice and nits using fine‑toothed combs or thorough washing of clothing and bedding at temperatures ≥ 60 °C.
- Topical insecticides such as permethrin 1 % or ivermectin cream for head louse eradication.
- Antibiotic therapy for bacterial diseases: doxycycline or chloramphenicol for epidemic typhus, azithromycin or doxycycline for trench fever, and a tetracycline regimen for relapsing fever.
Prevention focuses on personal hygiene, regular laundering of garments, and avoidance of overcrowded living conditions that facilitate body‑louse proliferation.