EPIDEMIOLOGIC COMPARISON OF HUMAN T-LYMPHOTROPIC VIRUS TYPE-I-INFECTED BLOOD-DONORS FROM ENDEMIC AND NONENDEMIC REGIONS OVER A 3-YEAR PERIOD

Background: Screening for human T-lymphotropic virus type I (HTLV-I) infection became systematic in 1989 in the French West Indies for blood from all donors and in France for blood from natives of endemic areas; in 1990, it was extended to blood from donors with at-risk sex partners and in July 1991 to blood from all donors. Study Design and Methods: The epidemiologic characteristics of individuals found through the screening of donated blood to be HTLV-I infected were compared for an endemic region (Guadeloupe, French West Indies) and a nonendemic region (Paris area) over a 3-year period (1989 through 1991). Results: In Guadeloupe, 131 HTLV-I-infected individuals were detected in the screening of 28,801 units; in the Paris area, 38 HTLV-I-infected donors were detected in the screening of 109,824 units. All Guadeloupean HTLV-I-infected donors were natives of endemic areas. Among the 38 Parisian HTLV-I-infected donors, 21 were natives of endemic areas, 10 were natives of endemic areas and had received transfusions, 2 were whites who had received transfusions, and 5 were whites who had had heterosexual contact with natives of endemic areas. The percentage of HTLV-I-infected individuals whose blood would have been excluded because of positivity for one or more markers for other viruses did not significantly change over the study period and did not significantly differ between regions (41%). Among the eight Parisian HTLV-I-infected blood donors detected after July 1991, six would not have been detected without the biologic screening. Conclusion: The generalization of biologic screening of HTLV-I-infected donated blood in France was useful for the prevention of HTLV-I and HTLV type II infections through transfusion.