Sexual behaviour of young people and the risk of HIV infection.

A survey of 16-21 year old people in Somerset was undertaken to find out about their sexual behaviour prior to mounting a local education campaign on AIDS. A representative sample of 400 people, using quota sampling in 40 randomly selected electoral wards, completed a schedule structured part self administered questionnaire. Of these, 371 (92%) considered themselves heterosexual. Nearly half (47%) of the 16 year olds had engaged in sexual intercourse, rising to 89% by the age of 21. Mean frequency of sexual intercourse among the sexually active is 62 per year. The frequency of partner change decreases with increasing age for non-virgins from 2.1 for 16 year olds to 1.5 partner changes per year for 21 year olds (mean frequency 1.7 per year, ie, a new partner every 7 months). This level of sexual activity could eventually give rise to HIV prevalence rates similar to those found in Africa, i.e., 15-100 HIV antibody positive per 1000.