Kaposi's sarcoma-associated herpesvirus and Kaposi's sarcoma in Africa

Background: Endemic Kaposi's sarcoma (KS) is a clinically and epidemiologically distinct human immunodeficiency virus negative form of KS occurring in Africa. Kaposi's sarcoma is now the most frequently reported cancer in some areas of Africa. Objective: To determine if a KS-associated herpesvirus (KSHV) is present in both endemic HIV-seronegative and HIV-seropositive KS lesions from African patients. Methods: Paraffin-embedded tissue specimens from Ugandan patients with KS and non-KS tumor control patients attending a university-based oncology clinic were examined in a blinded case-control study. Tissue DNA specimens were examined for detectable KSHV genome by nested polymerase chain reaction performed at two independent laboratories. Results: We identified KSHV in 17 (85%) of 20 KS tissue specimens from HIV-seronegative patients and 22 (92%) of 24 KS tissue specimens from HIV-infected persons. Kaposi's sarcoma lesions from four HIV-infected persons and four HIV-seronegative persons were positive for KSHV. Unlike previous studies in North America and Europe, three (14%) of 22 non-KS cancer control patients' tissue specimens were also positive for KSHV that resulted in an overall odds ratio of 49.2 (95% confidence interval, 9.1 to 335) for detecting KSHV in KS lesions from patients in Uganda. Conclusion: As in North America and Europe, KSHV infection is strongly associated with both HIV-seropositive and HIV-seronegative KS in Africa. However, it is likely that infection with this virus is more highly prevalent in Uganda.