Epidemiological changes in AIDS and HIV infection in Italy

This article describes the major changes in the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/ AIDS) epidemic in Italy, using data from the National AIDS Registry and from 5 local surveillance systems for new HIV diagnoses. From 1982 to 2001, 49,063 adults with AIDS were reported to the AIDS Registry. From 1988 to 2000, the 5 local systems reported 23,252 new HIV diagnoses. The AIDS incidence increased until 1995, followed by a progressive decrease. A decrease was also observed for the incidence of new HIV diagnoses after 1989, with an apparent stabilization after 1998. Most AIDS cases have been represented by intravenous drug users (IDU), yet since 1999 the percentage of cases attributable to sexual transmission has exceeded that for IDUs. Similarly, among new HIV diagnoses, the percentage of cases attributable to sexual transmission increased from 23.6% before 1993 to 58.5% in 2000. The percentage of people with AIDS who discovered their seropositivity no earlier than 6 months before AIDS diagnosis increased from 20.6% in 1996 to 48.8% in 2001. Although the incidence of both AIDS and new HIV diagnoses has declined, a possible resurgence of the epidemic cannot be ruled out, in light of various factors that could lead to an increasing number of living infected people.