Estimation of the residual risk for the transmission of HIV in blood donors from the mountain region of Santa Catarina.

The HIV, in hemotheraphy, may be transmitted by erythrocyte, platelets, crioprecipitated, frozen fresh plasma and possibly, by other blood components. Appropriate legislations for this new reality were elaborated normatizing the hemotheraphy practices in Brazil, creating a set of procedures and actions aiming at guaranteeing the quality of the blood, during the whole process. However, the residual risk remains, and it can be calculated as a product of the incidence and period of the immunological window. The objective [corrected] of the present study was to determine the rate of residual risk of the HIV blood transmission, in the blood donors from the Mountain Region of Santa Catarina. In order to calculate the residual risk of the HIV markers, 4,857 donors of repetition from the 24,969 individuals who donated blood from 2000 to 2003 were evaluated, and the results showed a serumconversion, in one case. The method used to calculate the residual risk followed the model of the immunological incidence window used by Schreiber (1996), in the USA. A estimate risk of 1:50,000 was verified. The case was considered as confirmed when one of the HIV, in the Hemocenter, is considered one of the HIV markers, in 1:50.000, which confirms the hypothesis that the new legislation related to the Blood National Politics, with the introduction of more sensible tests is decreasing the immunological window, diminishing the residual and, consequently, intensifying the transfusion security.