How are lice transmitted from person to person? - briefly
Lice spread mainly through direct head‑to‑head contact or by sharing hair accessories, hats, or brushes that have touched an infested scalp. Transmission via contaminated bedding, clothing, or other personal items can occur but is less frequent.
How are lice transmitted from person to person? - in detail
Lice move from one host to another primarily through direct head-to-head contact. When an infested person’s hair touches a susceptible individual, nymphs or adult insects crawl onto the new host within seconds. This mode of transfer accounts for the majority of outbreaks in schools, day‑care centers, and households where close physical interaction is common.
Secondary pathways involve sharing personal items that maintain enough warmth and humidity for the insects to survive. Comb, hairbrush, hat, scarf, pillowcase, or bedding that has recently contacted an infested scalp can harbor live lice or viable eggs (nits). Transfer occurs when such objects are placed on a clean head or when a person handles them and then touches their own hair.
Environmental reservoirs play a minor role. Lice cannot survive more than 24–48 hours off a human body; therefore, contaminated furniture, carpets, or upholstered seats rarely contribute to spread unless they are immediately adjacent to a person with an active infestation.
Key factors that increase risk include:
- Frequent close contact among children, especially during play or sports.
- Use of shared grooming tools without proper disinfection.
- Overcrowded living conditions that limit personal space.
- Lack of regular inspection and prompt treatment of infested individuals.
Effective prevention focuses on minimizing direct head contact, avoiding the exchange of hair accessories, and implementing routine checks of hair and scalp for live insects or nits. Prompt removal of lice and thorough cleaning of personal items interrupt the cycle of transmission.