[Epidemiology of HIV infection in Italy]

AIDS surveillance systems, which have provided for many years useful information on HIV epidemic dynamics, are no longer useful for estimating the evolution of the HIV epidemic due to the effect of anti-retroviral treatments that have strongly improved survival of HIV-infected persons. To obtain reliable data on the HIV epidemic, some Italian provinces and regions (Lazio, Veneto, Friuli Venezia-Giulia, Trento, Modena) have set up local surveillance systems of the new HIV diagnoses. Aggregated data collected by these systems since 1988, show that the rapid spread of the infection in the eighties has been followed by a progressive decrease in the number of new diagnoses during the nineties; in more recent years this trend has levelled-off. The composition of cases by exposure category has greatly changed over time: in 1988 75.2% of cases were injecting drug users, whereas in 2000 58.5% of cases acquired the infection through sexual contacts. HIV incidence for the considered areas decreased from 19.2 per 100.000 inhabitants in 1992, to 6.7 per 100.000 inhabitants in 2000. Median age at diagnosis increased over time, from 27 years in 1988 to 34 years in 2000. The changed pattern of the HIV epidemic in Italy stresses the need of a nation-wide surveillance system for HIV infections aimed at allocation of adequate economic resources and planning specific prevention programmes.