The epidemiology of AIDS-associated Kaposi's sarcoma in Italy

To describe the epidemiology of AIDS-associated Kaposi's sarcoma (KS) in Italy between January 1982 and September 1991.

To make this study comparable with previous research from other countries, statistical analysis of data from the Italian AIDS surveillance system was performed.

Odds ratios (OR) and 95% confidence intervals (CI) were used to examine the association between several characteristics of AIDS cases and the presence of KS as the presenting clinical manifestation of AIDS. Trends in the frequency of AIDS-associated KS were also estimated.

Of the 10,584 Italian AIDS cases reported up to September 1991, 720 (6.8%) had KS as the presenting clinical manifestation. In comparison with intravenous drug users (IVDU), of whom 2.6% had KS, homosexual or bisexual men had a nearly 10-fold higher risk of KS (OR, 10.2; 95% CI, 8.2-12.8), homosexual men who were also IVDU a nearly fourfold increased risk (OR, 4.4; 95% CI, 3.0-6.6) and heterosexuals a 2.6-fold risk (95% CI, 1.7-3.7). Men were more likely to have KS than women. The percentage of new AIDS cases with KS recorded each year in Italy declined from 12.0% in 1982-1986 to 5.8% in 1990-1991, a significant relative decrease of 19.0% per year (95% CI, 14.1-23.6%). The decline was observed among both IVDU (20% per year) and homosexual or bisexual men (11.4% per year). The frequency of KS was similar across age groups within each transmission category, whereas geographical differences emerged in the prevalence of AIDS-associated KS, especially among IVDU.

Our data on the epidemiology of AIDS-associated KS in Italy are similar to reports from North America and Europe, which show that KS is more common among individuals who acquired HIV infection by sexual transmission rather than parenterally, and that the incidence of this neoplasm is declining over time. The still poorly understood aetiology of AIDS-associated KS needs to be investigated further.