Increased condom use without other major changes in sexual behavior among the general population in Switzerland.

OBJECTIVES: This study is part of a continuous evaluation of the Swiss AIDS prevention strategy from 1987 through 1994. METHODS: Annual telephone surveys of samples representative of the general population aged 17 through 45 years have been conducted since 1987 to monitor behavioral change. RESULTS: No major changes in level of sexual activity (lifetime number of partners, frequency of sexual encounters in the past week) or potential exposure to risk of HIV transmission (acquisition of a new steady partner during the year or of casual partners in the last 6 months) were observed. Systematic condom use with a new steady partner increased between 1988 and 1994, from 40% to 64% among 17- to 30-year-olds and from 57% to 72% among those aged 31 to 45. Systematic condom use with casual partners increased from 8% to 56% between 1987 and 1994 among 17- to 30-year-olds and from 22% to 42% between 1989 and 1994 among those aged 31 to 45. Condom use was higher among those with multiple partners. CONCLUSIONS: A general-population approach to AIDS prevention was able to achieve large-scale improvements in condom-based protection against HIV infection without inducing other major changes in sexual behavior.