Absence of serological surrogate markers for Trypanosoma-cruzi-infected blood donors

Specific serological screening tests for Trypanosoma-cruzi-infected donors are not yet available and thus not routinely performed in North America. With the recent increase of Latin-American immigration to North America and Europe, there is a risk of transmission by blood products. In this study, we evaluated the possibility whether any of the serological screening tests currently recommended by the AABB could be used as a surrogate marker for this protozoarium. A group of 26,365 blood donors (male = 21,053 and female = 5,312) was analysed for the correlation of T. cruzi antibodies (TcAb) with other serological markers (HIV, HBsAg, ALT, HTLV-I/II, HCV, Anti-HBc, syphilis and unexpected hemoglobins other than A1, A2 and F). Association could be demonstrated only between syphilis and TcAb in the female group (p = 0.005), but the low number of donors found with this association (n = 4) renders the effect of this correlation very small. A higher prevalence of TcAb was found in older age groups, with even gender distribution (p < 0.05), however, donors aged more than 54 years also represent a minority of the donor pool (4.83%) and the detection of positive donors in this age group also has a minor preventive effect on transfusion-transmitted Chagas disease. We conclude that when infected blood donors must be detected, specific serological screening for TcAb is essential and that currently no surrogate marker can be considered for detecting T. cruzi-infected blood donors.