How can lice be transmitted? - briefly
Lice spread mainly through direct head‑to‑head contact and, less commonly, by sharing personal items such as combs, hats, or bedding. Transmission can also occur when contaminated objects are handled and subsequently placed on the scalp.
How can lice be transmitted? - in detail
Lice spread primarily through close physical contact. The most common route is direct head‑to‑head interaction, which allows adult insects or nymphs to move from one scalp to another within seconds.
Sharing personal items creates additional pathways. Combs, brushes, hats, helmets, hair accessories, and earbuds can retain live insects or viable eggs; when another person uses the contaminated object, lice are transferred.
Bedding and clothing serve as secondary vectors. Towels, pillowcases, pillow‑covers, and sheets can harbor lice for several days. Contact with these fabrics, especially in crowded living conditions, facilitates transmission.
Fomites—objects that have been in contact with an infested person—play a supporting role. Although lice cannot survive long off a host, eggs (nits) may remain viable for up to 48 hours on surfaces such as upholstered furniture or shared equipment, enabling indirect spread.
Pubic lice (Pthirus pubis) follow a distinct pattern. Sexual contact is the predominant mechanism, but transmission can also occur via shared bedding, towels, or clothing that contacts the genital area.
Animal‑associated lice, such as body lice (Pediculus humanus corporis), spread through clothing and personal hygiene deficits. Infestation arises when clothing is worn for extended periods without regular washing, allowing lice to move from the garment to the body.
Environmental factors increase risk. High‑density settings—schools, daycare centers, camps, prisons, and shelters—provide frequent opportunities for head‑to‑head contact and item sharing, accelerating the spread of head lice.
Key characteristics of lice limit their mobility: they cannot jump or fly, relying on crawling. Consequently, transmission requires physical proximity or contact with contaminated objects, making personal hygiene and avoidance of shared items essential control measures.