The spectrum of AIDS-defining diseases: temporal trends in Italy prior to the use of highly active anti-retroviral therapies, 1982-1996

OBJECTIVE: To evaluate time trends of the spectrum of AIDS-defining diseases in Italy, 1982-1996. METHODS: Surveillance data from the Italian National AIDS Registry were used to assess temporal patterns of all AIDS-defining diseases diagnosed among adults as of December 1996. Twenty-six initial clinical manifestations of AIDS were grouped into 12 categories. Relative frequencies were calculated by year of diagnosis and stratified by age, gender, HIV-exposure category, and CD4+ cell count. A multivariate polychotomous logistic model was used to estimate the proportions of each diagnostic category over time, adjusting simultaneously for the remaining diagnostic categories and for variables of interest. RESULTS: This analysis was based on 41772 diagnoses of AIDS-defining diseases among 36 638 reported cases. Mycoses represented the most frequent condition (27.3%), followed by Pneumocystis carinii pneumonia (PCP) (21.4%) and viral infections (8.9%). Cancers accounted for less than 10% of diseases. Downward trends were observed for mycoses, PCP (in the last part of the study period), Kaposi's sarcoma (KS), and non-Hodgkin's lymphomas (NHL). Upward trends were observed for mycobacterioses, and bacterial and protozoal infections. Brain toxoplasmosis increased up to 1994, and, thereafter, it appeared to decrease. These trends were less marked when the analysis was restricted to the diseases included in the pre- 1987 AIDS definition. Trends stratified by CD4+ cell count for the period 1990-1996 were substantially consistent with the above-reported results. CONCLUSIONS: The downward temporal trends in the most recent years of the study period for PCP and for brain toxoplasmosis are likely to be related to the use of prophylactic treatment. This analysis confirms a decline in KS but suggests that this was largely over by 1990.