Biological, epidemiological and clinical basis of understanding human immunodeficiency virus infection.

Human immunodeficiency virus (HIV) causes a chronic infection beginning in most individuals with an acute syndrome followed by an asymptomatic stage and progresses in untreated adults over a median of 10 years to the late stage called AIDS. The virus rapidly and enormously replicates from the initiation of infection. The principal immunodeficiency caused by HIV is depletion in the subset of T lymphocytes referred to as helper T cells. New anti-HIV drugs given in potent combination regimens have demonstrated impressive efficacy by both clinical and laboratory measures, and have provided evidence that drugs can suppress HIV replication and disease manifestations. HIV/AIDS is still uncommon in Croatia. In the period from 1986 to 2000, 171 patients with AIDS have been reported of whom 101 (59%) died. The incidence of AIDS in 2000 was about 4 cases per million inhabitants. Recent testing of injection drug users at a needle exchange program (Help, Split) revealed an HIV incidence of about 1%.