Between December 1998 and March 2001, for each HTLV-I/II seropositive blood donor (ELISA, Abbott®), two HTLV-I/II seronegative blood donors were also chosen. The blood samples were re-tested by ELISA (Murex®), and those seropositives were also tested by western blot and PCR. Of the 11,121 blood samples, 73 (0.66%) were positives (Abbott®), but only 12 (0.11%) remained positives (Murex®), whereas the 146 seronegatives were confirmed, even though the concordance index between these two ELISA tests was hopeless. The Western Blot confirmed the twelve blood samples as seropositives: 8 (0.07%) HTLV-I; two (0.02%) HTLV-II and two (0.02%) indeterminate, being by PCR, one HTLV-I and the other HTLV-II. Concluding, in this Western Amazon population the HTLV-I/II seroprevalence was too low, in spite of the greater prevalence of HTLV-II expected due to a great indigenous racial mixture.
HTLV-I/II; Blood donors; Prevalence; Acre; Western Amazon
