Seroprevalence of Kaposi's sarcoma-associated herpesvirus in various populations in Cuba

Objective. Little is known about the prevalence and distribution of Kaposi's sarcoma-associated herpesvirus (KSHV) infection in the Caribbean. The aim of this study was to determine rates of KSHV seropositivity in various populations in Cuba. Methods. During the years 1998 to 2002 we screened serum samples from 410 subjects in Cuba. Serologic screening for KSHV antibodies was a two-step process using (1) indirect immunofluorescence assay (IFA) specifically reactive to the KSHV latency-associated nuclear antigen (LANA) encoded by open reading frame 73 (ORF73), and (2) confirmatory immunoblot using recombinant KSHV ORF65.2, a lytically expressed, 20-kilodalton protein as the target antigen. Five different populations were studied: (1) 45 AIDS patients with Kaposi's sarcoma (AIDS-KS), (2) 154 HIV-1-infected patients without clinical evidence of KS, (3) 171 HIV-negative blood donors, (4) 27 consecutive kidney transplant recipients, who were HIV-negative, and (5) 13 contacts (sexual contacts or relatives) of the AIDS-KS-affected patients. Results. Among the 45 AIDS-KS subjects, 35 of them (77.8%) were KSHV-seropositive. Thirty-two of the 154 HIV-positive patients without KS (20.8% of them) were KSHV-seropositive, and 6 of the 13 contacts of KS-affected patients (46.2% of them) were infected with KSHV. In contrast to other researchers, we did not find in the populations that we studied in Cuba that KSHV seropositivity was associated with male homosexual or bisexual activity. We found high KSHV seropositivity rates among women reporting sexual contact with bisexual men and among men who had acquired an HIV infection in Africa. There were low rates of KSHV infection among the blood donors (1.2%) and the renal transplant recipients (0.0%). The low rates of KSHV infection that we found among the non-HIV-infected populations in Cuba are similar to patterns found in populations in Europe and in the United States. Conclusions. Together with similar results from Brazil, Jamaica, and the United States Of America, our results suggest that KSHV infection is uncommon in some populations in the Western Hemisphere and that KSHV is largely confined to patients with AIDS-associated KS.