To whom are lice transmitted? - briefly
Lice are passed mainly between people through direct head‑to‑head contact and, less commonly, via shared items such as combs, hats, or bedding. They do not infest animals or other species.
To whom are lice transmitted? - in detail
Lice are obligate ectoparasites that spread primarily through close physical contact and shared personal items. Head lice (Pediculus humanus capitis) transfer most efficiently when individuals touch heads, a common occurrence among school‑age children, preschoolers, and their caregivers. Sharing combs, hats, helmets, hair accessories, or pillows also facilitates transmission, especially in environments where hygiene practices are inconsistent.
Body lice (Pediculus humanus corporis) migrate from clothing to skin and are transmitted when infested garments are exchanged or when contaminated clothing is worn without regular laundering. Populations at heightened risk include persons experiencing homelessness, refugees, and individuals residing in crowded or unsanitary conditions where clothing changes are infrequent.
Pubic lice (Pthirus pubis) spread chiefly through sexual contact, but can also be transmitted via close skin‑to‑skin contact in non‑sexual contexts, such as shared bedding or towels. High‑risk groups encompass sexually active adults, particularly those with multiple partners or those attending venues where intimate contact is common.
Additional vectors include:
- Direct skin contact during sports, wrestling, or other close‑contact activities.
- Use of contaminated fomites (combs, brushes, scarves, headphones).
- Overcrowded living situations (dormitories, prisons, military barracks).
Risk factors augmenting susceptibility comprise:
- Limited access to clean clothing and personal hygiene supplies.
- Lack of routine laundering at temperatures sufficient to kill lice (≥130 °F/54 °C).
- Crowded childcare settings where children interact frequently.
- Immunocompromised status, which may increase infestation severity.
Preventive measures focus on minimizing contact with infested individuals, maintaining personal hygiene, and regularly washing clothing and bedding at high temperatures. Prompt identification and treatment of infestations reduce the likelihood of further spread within communities.