Aendringer i immunstatus blandt nydiagnosticerede hiv-inficerede i Danmark 1995-2005

INTRODUCTION The incidence of new HIV diagnoses in Denmark has remained stable since 1991, but it has increased among the subgroup of homosexual men in recent years. This may reflect an actual increase in newly infected, e.g. as a result of increased risk behaviour, or it may reflect increased HIV testing. To clarify the causes of this increase we describe and analyse the development of HIV infection in Denmark in the period 1995-2005 with special emphasis on the route of transmission, immunological status at the time of diagnosis and the prevalence of patients at risk of transmitting HIV. MATERIALS AND METHODS Observational study based on the Danish HIV Cohort Study, which includes all adults seen at Danish HIV clinics since 1995. RESULTS From 2000 to 2004 the number of newly-infected homosexual men increased (from 69 to 123), particularly in persons under 30 years (from 5 to 42). The median CD4 cell count at the time of diagnosis increased in this group (median 19.1 cells/microL per year [95% CI: 3.7-11.3]), while it remained stable among heterosexually infected. The number of newly-diagnosed homosexually infected under 30 years with a CD4 cell count over 400 cells/microL increased from 0 in 2000 to 23 in 2004. The prevalence of patients with high viral load (and thus potentially at risk of transmitting HIV) decreased in all risk groups. CONCLUSION Newly-diagnosed homosexual men present at an earlier stage of disease progression and with a better preserved immune system today than 5-10 years ago, presumably due to a combination of frequent HIV testing and increased risk behaviour among young homosexuals in particular. Increased preventive measures targeting known risk groups are necessary to prevent further spread.