The prevalence of antibodies against human T-cell lymphotrophic virus
(HTLV-I/II) in blood donors from the city of Monterrey, Mexico was inv
estigated, We found that 4 out of 1017 sera (0.39%) reacted against HT
LV-I/II, as determined by a passive agglutination test (PA), However,
none of PA-positive sera reacted to HTLV-I/II specific polypeptides as
demonstrated by Western blot, These findings indicate that the popula
tion of Monterrey has very low or no seroprevalence for HTLV-I/II.