How can you catch lice from another person? - briefly
Head-to-head contact or sharing personal items such as combs, brushes, hats, or hair accessories transfers lice between individuals. Maintaining personal hygiene and avoiding the exchange of these objects prevents transmission.
How can you catch lice from another person? - in detail
Lice spread primarily through direct head‑to‑head contact. When hair from an infested person brushes against another’s scalp, the female adult can lay eggs on the new host within seconds. The insects cannot jump or fly; they move only by crawling, so close physical proximity is essential for transmission.
Key mechanisms of acquisition include:
- Shared headgear – hats, scarves, helmets, hair clips, or barrettes that have touched an infected scalp can harbor live lice and nits.
- Combed or brushed items – hairbrushes, combs, and styling tools used on an affected individual may retain eggs or nymphs, which survive for several days.
- Bedding and upholstery – pillowcases, blankets, couch cushions, and car seats that have been in contact with an infested head can contain lice, especially if the environment is warm and humid.
- Clothing – coats, scarves, or hoods that have been worn over an infested head may transfer insects when the wearer removes them and another person puts them on.
Transmission does not occur through casual contact such as shaking hands, sharing food, or using the same bathroom. Lice require a stable temperature (approximately 30 °C) and a blood meal every few hours; therefore, they survive only on human heads. Eggs (nits) remain viable for up to a week away from a host, allowing them to hatch after the contaminated item is placed on a new scalp.
Preventive measures focus on eliminating these vectors: avoid sharing personal accessories, wash and dry contaminated fabrics at high temperatures, and disinfect combs and brushes by soaking in hot water (≥50 °C) for at least 10 minutes. Prompt detection and treatment of an infestation reduce the risk of spreading to others.