What causes pubic lice? - briefly
Pubic lice are transmitted primarily through sexual contact or close skin‑to‑skin interaction with an infected individual. Secondary transmission can occur via infested bedding, towels, or clothing that have not been properly laundered.
What causes pubic lice? - in detail
Pubic lice, Pediculus pubis, are obligate ectoparasites that survive exclusively on human hair, primarily in the pubic region. The insects obtain nourishment by feeding on blood, requiring direct contact with an infested host for survival and reproduction.
Transmission occurs through:
- Sexual intercourse, including vaginal, anal, and oral contact, which provides the most efficient route for lice exchange.
- Non‑sexual skin‑to‑skin contact, such as sharing bedding, towels, or clothing that have recently harbored live insects.
- Close physical proximity in crowded environments, for example, communal living quarters or shelters, where inadvertent contact with contaminated fabrics is possible.
Key biological factors that enable infestation:
- Life cycle – Eggs (nits) are cemented to hair shafts and hatch within 7‑10 days; nymphs mature into adults after 10‑14 days, completing a cycle of roughly 3 weeks.
- Temperature and humidity – Optimal development occurs at body‑surface temperature (≈ 34 °C) and moderate humidity; extremes impede survival.
- Host hair characteristics – Coarse, curly hair in the genital area offers a suitable substrate for attachment and egg deposition.
Risk‑enhancing conditions include:
- Multiple sexual partners, which increase exposure probability.
- Inadequate personal hygiene or infrequent laundering of personal items, allowing nits to remain viable.
- Immunocompromised status, which may facilitate prolonged infestation due to delayed clearance.
Prevention relies on minimizing direct contact with infested individuals, avoiding shared personal items, and promptly treating confirmed cases with approved topical pediculicides. Early detection and treatment interrupt the life cycle, reducing the chance of secondary spread.