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Background: The practice of platelet (PLT) transfusions has been adopted into the standard clinical practice in many dengue-endemic countries. Because many patients were found to have received unnecessary PLT transfusions, the development of guidelines for the management of dengue patients with thrombocytopenia has become a necessity., Study Design and Methods: An emergency department-based prospective observational study was conducted in Martinique during a dengue outbreak in adult patients presenting with an acute febrile illness. Patients with severe bleeding and/or who underwent invasive intensive care procedures or emergency surgery were given PLT transfusion to achieve PLT counts of more than 50 x 10(9)/L. PLT transfusion was also considered for patients with PLT counts of less than 5 x 10(9)/L and for those with associated risk factors and PLT counts of less than 20 x 10(9)/L., Results: A total of 350 patients were admitted with confirmed dengue infections. Most of them had secondary serotype-2 infections. PLT counts of less than 50 x 10(9)/L were recorded in 165 patients (47.1%). PLT transfusion was administered to 9 patients with thrombocytopenia. The indications included severe bleeding (5 cases), invasive procedures (3 cases), emergency surgery (1 case), and/or associated risk factors (2 cases). The median time duration from the onset of fever to PLT transfusion was 6 days (range, 4-10 days). The median amount of PLTs transfused was 3.66 x 10(11) (range, 2.8 x 10(11)-13.2 x 10(11)). The median PLT yield was +12.4% (range, -3.9% to +67.1%). Three patients died. All other patients recovered during the second week after the onset of fever., Conclusion: A restrictive strategy for PLT transfusion based on clinical features and low PLT count thresholds proved to be feasible and safe for adult dengue patients.

Background: WBC depletion by filtration may prevent the transmission of HTLV-I, which requires cell-to-cell contact. The removal of HTLV-I-infected cells in routinely filtered blood cell components was measured., Study Design and Methods: The study was conducted in Martinique where systematic screening for HTLV-I and -II and universal leukoreduction are mandatory. HTLV-I was quantified by use of real-time PCR in 8 RBC units and 4 PLT concentrates before and after filtration. HTLV-I proviral load in PBMNCs was determined in five of the eight HTLV-I-infected blood donors., Results: The amount of MNC-associated HTLV-I DNA in RBC units before filtration was 21 x 10(6)+/- 29 x 10(6) copies (mean +/- SD). HTLV-I was detected in 4 of 8 RBC units after filtration, with a number of copies in the MNC fraction ranging from 20 to 140, following a 4.9 to 5.8 log reduction. Flow cytometry analysis performed in 2 of the filtered RBC units containing detectable HTLV-I showed suboptimal and out-of-range leukoreduction (0.56 x 10(6) and 1.22 x 10(6) residual WBCs). HTLV was not detected in filtered RBCs from the blood donor with the highest percentage of HTLV-I-infected PBMCs (9%)., Conclusion: This study confirms that HTLV-I-infected cells can be detected in filtered blood cell components and shows that optimal leukoreduction is critical for HTLV-I removal.

Background: Screening for human T-lymphotropic virus type I (HTLV-I) antibodies in volunteer blood donors has been systematic in the French West Indies since 1989. Western blot-indeterminate results are commonly obtained. The significance of these indeterminate serologic patterns in HTLV-I-endemic areas is still unclear., Study Design and Methods: During a 2-year period, 9759 blood donors were tested for HTLV-I antibodies. The epidemiologic features of HTLV-I-seropositive, -seroindeterminate, and -seronegative donors were compared. A lookback investigation was performed for the HTLV-I-seropositive donors, and the HTLV-I-seroindeterminate individuals were followed up., Results: Thirty-nine donors (0.4%) were HTLV-I seropositive and 49 (0.5%) were seroindeterminate. The age and sex ratio characteristics of the seroindeterminate donors are divergent from those of the HTLV-I-seropositive group and are more like those of the seronegative population. However, during the study period, three cases of seroconversion after an initial seroindeterminate profile were reported. Two cases were detected through follow-up of 38 HTLV-I-seroindeterminate donors over a mean of 8 months (2-24 months). The third seroconverter belonged to the HTLV-I-seropositive group and was identified through lookback investigation. This case is atypical, with p19 reactivity for several months before HTLV-I seropositivity., Conclusion: These findings indicate that, although HTLV-I-seroindeterminate donors mainly are HTLV-I-noninfected, the rate of seroconversion in a repeat blood donor population from an endemic region must be taken into consideration. Moreover, the case of delayed seroconversion observed in this study suggests the difficulty of counseling seroindeterminate blood donors in endemic regions.