Prevalence of serum antibodies to human T lymphotropic virus-1 in an isolated tribe in the highlands of Irian Jaya, Indonesia
Anthony, R.L.; Jennings, G.B.; Sie, A.; Ratiwayanto, S.; Bangs, M.J.
American Journal of Tropical Medicine and Hygiene 48(2): 230-236
1993
ISSN/ISBN: 0002-9637 PMID: 8447528 Document Number: 409155
There have been several recent reports on the high prevalence of serum antibodies to human T lymphotropic virus-1 (HTLV-1) in isolated populations residing in the coastal areas and highlands of Papua New Guinea. In the absence of significant cases of clinical disease, it has been surmised that this reactivity might be the consequence of serologic recognition of yet undefined human retroviruses or pasasite antigens. These observations prompted in investigation of the prevalence of anti-HTLV-1 antibodies among members of the Ngalum tribe that dwells in the secluded highland valley in the eastern members of the Nagalum tribe that dwells in a secluded highlang valley in the eastern Jayawijaya Mountains of Irian Jaya, Indonesian New Guinea. Of 165 tribespeople, 85 (52%) were positive for IgG antibodies of HTLV-1 in an indirect enzyme-linked immunosorbent assay. Eighty-two were more than 10 years of age. On the Western blot, all positive sera reacted strongly with p19 core antigen, but recognition of the envelope antigens, gp46 and gp21, was conspicuously absent. Thirty-four of the 85 villagers with these indeterminant blots had active Plasmodium falciparum infections, but antibody absorption studies with HTLV-1 and P. falciparum erythrocytic stage antigens failed to confirm suspected serologic cross-reactivities. Thirty-three others had acute malaria and/or high titers of anti-malaria antibodies were seronegative for HTLV-1. We suspect that indeterminant Western blots for HTLV-1 reflect antibody reponses to related latent retroviruses that are activated as a consequence of immunosuppression following malaria infection and chloroquine thearpy.