High prevalence of HTLV-I and HTLV-II among blood donors in Argentina:: A South American health concern

After an HTLV- I endemic area was discovered in Jujuy, a northwestern province in Argentina, to detect other possible foci of HTLV- I/ II we started in 1997 a multicentric study to estimate the seroprevalence of HTLV- I/ II including blood banks from different regions of the country. Out of 123,233 samples from nine different provinces, 68 proved seropositive with a final prevalence of 0.05% ( 95% CI = 0.0432 - 0.0704%). The seroprevalence ranged from 0.03 to 0.16% depending on the geographic location. An HTLV- I [ odds ratio ( OR) 12.7, 95% confidence interval ( CI), 3.43 - 47.60] prevalence significantly greater was found in the northwest ( Salta Province) and a nonsignificant but higher prevalence of HTLV- II in the North ( Chaco). Two ( 0.001%) of the seropositive blood donors reported risk factors due to receiving transfusions and 19 ( 0.01%) were born in HTLV- I/ II South American endemic areas. Although Argentina has been considered a nonendemic country for HTLV- I/ II, the need for systematic screening for such infection became imperative based on the present study.