AIDS DEMENTIA COMPLEX IN THE ITALIAN NATIONAL AIDS REGISTRY - TEMPORAL TRENDS (1987-93) AND DIFFERENTIAL INCIDENCE ACCORDING TO MODE OF TRANSMISSION OF HIV-1 INFECTION

Objectives: To investigate the occurrence of AIDS dementia complex (AD C) in Italy and its incidence over time, examining possible correlatio ns between this condition and some demographic and immunological varia bles. Design. Inception cohort. Data collected from the case notificat ion forms of the Italian National AIDS Registry. Subjects: 16813 conse cutive AIDS cases reported to the National AIDS Registry from August 1 , 1987 through October 31, 1993 were included. Statistical methods: Al l data refer to the time of AIDS diagnosis as reported on the case not ification forms. Main analyses of the monthly proportion of ADC cases were by multiple logistic regression. Results: 1364 subjects (8.1%) we re reported with a diagnosis of ADC as the first AIDS defining disease , either as the only manifestation or associated with other AIDS defin ing conditions. At the time of AIDS diagnosis, the observed ADC/AIDS p roportion was significantly higher among intravenous drug users (IVDU) , 9.1%, compared to heterosexuals. 6.3%, and home-bisexual men, 5.2%. Simple logistic regression analysis showed a significant (p < 0.0001) quadratic trend in the monthly ADC/AIDS proportion, peaking in March 1 990 and decreasing thereafter. Multiple logistic regression, adjusting for month of diagnosis, showed that IVDUs have consistently the highe st risk and home-bisexual men the lowest, although differences tended to decrease with increasing age. Older age, in fact, was highly associ ated with an increased risk, especially within the home-bisexual and h eterosexual transmission categories. CD4+ cells counts proved to have no significant effect on the risk of progressing to AIDS with ADC rath er than with any other AIDS indicative disease. Conclusions: ADC is a relatively frequent manifestation at diagnosis of AIDS among Italian p atients, and particularly in IVDUs. Differences in its occurrence were found according to time of diagnosis, transmission category and age.