Temporal trend of HIV infection: an update of the HIV surveillance system in Lazio, Italy, 1985-2000.

Background: After the introduction of the highly active antiretroviral therapies, data from AIDS surveillance systems are less useful to describe the HIV epidemic, while HIV surveillance could give more detailed information to provide data for HIV prevention and care programmes. We report the results of the HIV surveillance system update in Lazio, Italy, from 1985 through 2000.
Methods: New diagnoses of HIV infection were identified through a linkage procedure on the total reports, and underreporting was estimated through a link between the HIV surveillance system and the Hospital Information System of Lazio.
Results: As of December 2000, 20,912 new diagnoses of HIV occurred in Lazio. New diagnoses have decreased steadily since 1992. The male/female ratio decreased during the study period, while the number of foreign-born cases increased. Sexual transmission became the main modality of exposure for men in 1996 and for women in 1992. In 2000 the proportion of men infected by sexual transmission reached 54.0% versus 15.2% of those infected by intravenous drug use, whereas the proportion of women was 58.9% and 8.6% respectively. The sensitivity of the system has slightly decreased.
Conclusion: HIV infection is increasing in women and immigrants; people are being infected more frequently by sexual transmission than intravenous drug use.