THE PREVALENCE OF ANTIBODIES TO HUMAN T-LYMPHOTROPIC VIRUS TYPE-I IN DIFFERENT POPULATION GROUPS IN PAPUA-NEW-GUINEA

Isolation and partial sequencing of human T-lymphotropic virus type I (HTLV-I) variants from inhabitants of Papua New Guinea (PNG) and the S olomon Islands has confirmed the existence of virus infection in Melan esian populations. To determine the geographical distribution of serop ositivity to HTLV-1 in PNG we have tested 2907 serum and plasma sample s collected between 1972 to 1991 from 16 different population groups. Samples were screened using a particle agglutination assay and confirm ed by p21e-enhanced Western immunoblot (WB). From a total of 94 screen positive samples run on WB, 56 (60%) were confirmed positive (positiv e for both env and gag products) and 38 (40%) were WB-indeterminate (g ag products only). The prevalence of WB-confirmed antibodies to HTLV-1 in lowland and island populations ranged from 0 to 5.4%. There were n o confirmed antibody positives in the highland populations surveyed. G eographically isolated populations living on the fringes of the highla nds ranged in seropositivity from 0.2 to 5.8%. Two of the subjects sur veyed gave WB antibody patterns characteristic of HTLV-II rather than HTLV-1 infection.