What disease is transmitted by lice? - briefly
Lice transmit epidemic typhus, an infection caused by Rickettsia prowazekii, and can also spread trench fever (Bartonella quintana). These vector‑borne diseases are transmitted when infected lice are crushed or when their feces enter skin abrasions.
What disease is transmitted by lice? - in detail
Lice serve as vectors for several serious infections, the most notable being epidemic typhus. The causative agent, Rickettsia prowazekii, resides in the gut of the body louse (Pediculus humanus corporis). When the insect feeds, it defecates on the host’s skin; subsequent scratching introduces contaminated feces into abrasions, allowing bacterial entry. Symptoms appear after a 5‑ to 14‑day incubation and include abrupt high fever, severe headache, macular rash that spreads from trunk to extremities, and delirium. Mortality can exceed 10 % without prompt therapy; doxycycline is the drug of choice, with chloramphenicol as an alternative.
Another pathogen transmitted by the same species is Bartonella quintana, the agent of trench fever. After an incubation of 5‑20 days, patients develop relapsing fever spikes, severe leg pain, and a faint maculopapular rash. The disease is self‑limiting but may persist in immunocompromised individuals; azithromycin or doxycycline provide effective treatment.
Borrelia recurrentis causes louse‑borne relapsing fever. The spirochete is acquired in the same manner as the other agents. Clinical presentation features recurrent episodes of high fever lasting several days, each followed by a symptom‑free interval, accompanied by headache, myalgia, and a petechial rash. Tetracycline antibiotics rapidly clear the infection; resistance is rare.
Head lice (Pediculus humanus capitis) rarely transmit pathogens. Their primary health impact is localized itching and secondary bacterial infection from skin lesions.
Control measures focus on eliminating the vector:
- Frequent laundering of clothing and bedding at ≥60 °C or dry cleaning.
- Use of topical pediculicides (permethrin, ivermectin) for active infestations.
- Environmental decontamination of personal items, avoiding sharing of hats, scarves, and hair accessories.
- Prompt treatment of identified cases to reduce bacterial load in the louse population.
Surveillance in crowded or unhygienic settings—refugee camps, prisons, homeless shelters—remains essential, as outbreaks of louse‑borne diseases correlate with poor sanitation and close contact. Early recognition of clinical signs and immediate antimicrobial therapy dramatically lower morbidity and mortality.