Ohkura Sadayuki, Yamashita Masahiro, Cartier Luis, Gutierrez Tanabe David, Hayami Masanori, Sonoda Shunro, Tajima Kazuo
Laboratory of Viral Pathogenesis, Research Center for AIDS, Institute for Virus Research, Kyoto University, 53 Shogoin-Kawahara-machi, Sakyo-Ku, Kyoto, Japan1.
Department of Neuropathology, Chile University, Chile2.
J Gen Virol. 1999 Aug;80 ( Pt 8):1995-2001. doi: 10.1099/0022-1317-80-8-1995.
Human T-cell leukaemia virus type I (HTLV-I) is endemic in Melanesia, one of the three ethnogeographic regions of the Pacific; in the other two regions, Polynesia and Micronesia, the incidence of the virus is relatively low. In an effort to gain new insights into the prevalence of HTLV-I in the Pacific region, we did a seroepidemiological survey on Easter Island, which is located on the eastern edge of Polynesia. Of 138 subjects surveyed, including 108 Rapa Nui (the native inhabitants of this island), we identified one HTLV-I-seropositive Rapa Nui. The new HTLV-I isolate derived from this carrier (E-12) was phylogenetically analysed to ascertain the origin and past dissemination of HTLV-I in the island. The analysis demonstrated that isolate E-12 belongs to subgroup A of the Cosmopolitan group, and that it differs from HTLV-Is found in Melanesia, which are highly divergent variants. In subgroup A, E-12 grouped with South American HTLV-Is including those from Amerindians. This result suggests that this isolate originated in South America rather than in Melanesia.