Resum

Background: HIV transmission in adolescents and young people provides a key to the future of the epidemic. Our objective was to analyze the time-trends in the number diagnoses of HIV infection and seroprevalence among very young adults and adolescents after having had any practice with risk for HIV transmission. Methods: The study was done in a STI clinic in Madrid. We included all persons aged 13 to 20 who were tested for HIV between 2004 and 2009. The prevalence and the number of HIV diagnoses over the years were analyzed according to sex, transmission category and whether it was the first HIV test or a repeat of the same. Results: During the study 1627 patients from 13 to 20 years were tested for HIV. The number of people tested annually ranged from 234 in 2004 and 391 in 2007. The number of HIV diagnoses increased from 2 in 2004 to 15 in 2009, and the seroprevalence of HIV infection augmented from 0.9% to 4.8% (chi2 for trend, p < 0.001). In the 2004-2005 period 7 infections were diagnosed, of which 4 were in men who had sex with men (MSM) and 3 female sex workers. Five immigrants were diagnosed, 4 were from sub-Saharan origin. In 2008-2009 25 infections were diagnosed, 24 were male and 20 were MSM. Fourteen of those diagnosed were born in Spain and 6 in Latin America. Three of the infections were detected in MSM who had had a previous negative test in the same clinic. Between the two periods, the HIV seroprevalence increased among MSM from 2.6% to 8.7% (p = 0.02). Conclusion: There was an increase in the number of new HIV diagnoses in adolescents and very young adults. The predominant pattern of immigrants and heterosexual transmission in Madrid has been displaced by the transmission among MSM, mostly natives. (Resumen de los autores)