Résumé
Since January 6th 1994 to December 31 1997. We researched hepatitis C Virus antibodies by second and third generation ELISA in 34130 bloods donors living in "Sahel Tunisien". 193 were positive [0.56 percent]. Only 171 of them were secondary tested by immunoblat assay [anticore, anti N55, anti NS3, Anti NS4]. Which was positive in 53 cases [30.9 percent]; indeterminated [presence of only one antibody] in 78 cases [45.6 percent] and negative, in 40 cases [23.3 percent]. There was a significant relation between a ratio over than 2.5 in ELISA and immunoblot positivity. Immune response to different hepatitis virus antigens were heterogenous with predo-minat indeterminated profile. [78/171 cases]. Most of donors of the last profile had either anti NS5 [32/78] or anti NS3 [33/78] and we excluded them even through usually negative in P.C.R. and associated with a very low risk of contamination