[HIV infection among young people in Denmark 1990-1999]

The aim of the study was to describe the spread of HIV among young people below 25 years of age in Denmark and further to estimate the risk of acquiring HIV in heterosexuals in Denmark by means of a simple model.

Data from the mandatory national HIV surveillance were analysed. The risk of acquiring HIV was estimated by a simplified mathematical model with estimates of HIV prevalence, risk of transmission per sexual act, and number of sex partners.

A total of 266 persons below 25 years of age had HIV infection: 127 men (48%) and 139 women (52%). The most dominant mode of transmission was sexual: 55% were infected heterosexually and 29% homosexually. One hundred and fourteen persons (43%) were foreigners, 87% of whom had been infected outside Denmark. A decreasing trend was found over the years in the number of first-time identified HIV infected persons, overall as well as in Danes, p < 0.01. The annual rate of HIV detection in women aged 20-24 years was calculated to be 2.5 per 10(5) Danish women.

The spread of HIV among young Danes seems limited when the data on cases diagnosed over the last decade were analysed, and the general risk of acquiring HIV through unprotected intercourse is very low--regardless of changes in partner. Sub-groups of heterosexuals at high-risk may exist, and if so these should be identified.