• BEHAVIOURAL SCIENCE
• SEXUAL BEHAVIOUR
• HIV

Despite systems to monitor the incidence of disease dating from the mid-1800s,1 behavioural surveillance is in relative infancy. The first systematic data on human sexual behaviour, the Kinsey Reports, were published in the late 1940s/early 1950s, but it was not until 40 years later that national systematic efforts to collect data on sexual behaviours were undertaken. Great Britain's National Surveys of Sexual Attitudes and Lifestyles (NATSAL) and the National Health and Social Life Survey in the USA were both launched in the early 1990s in response to the emerging HIV/AIDS epidemic, and both were accompanied by significant debate about public funding of research on the still taboo subject of sexual behaviour. Today, taboos have loosened and systematic collection of data on sexual behaviour is routine in many settings. Nevertheless, there are few instances of data that can be compared across time and geographical location. In response to this, the European Centre for Disease Prevention and Control (ECDC) launched an effort to harmonise behavioural surveillance by recommending uniform collection of core indicators across populations. In this issue, Jørgensen et al describe results of Denmark's baseline behavioural surveillance survey using the ECDC core indicators in a general population sample of young adults (see Jørgensen et al). Approximately 30% did not use condoms at sexual debut, placing them at risk of sexually transmitted infections (STI). Even more were unprotected at their last sexual encounter, and this was amplified in casual partnerships. While the results themselves are not surprising, the establishment of baseline data for the ECDC core indicators in Denmark …