Control of Trypanosoma cruzi infection in blood donors in Colombia, 2003.

Abstract

Introduction. Chagas disease is a public health problem in Latin America. Whereas the primary source of transmission is the insect vector, the second is by blood transfusion. Consequently, in Colombia, screening for trypanosomiasis has been obligatory for blood donors since 1995.
Objective. The effectiveness ot current strategies for infection control in donors was evaluated in order to estimate the risk of blood stock contamination with Chagas disease. The screening data came from the blood banks in the Program of External Evaluation in the Performance of Serology and the reports of the Laboratories of Public Health on confirming donor serology tests.
Results. In 2003, 482,371 units of blood were collected in all of Colombia. Of these, 99.9% were analyzed for anti-T. cruzi reactivity, with a positives of 0.42% detected. The Casanare Province presented the biggest number of reactive donors 107/1487 (7.2%), with 75 confirmed positive. In the Program of External Evaluation in the Performance of Serology, 45.5% of all banks participated-all used ELISA for screening of anti-T. cruzi. 1.1% false positives and nofalse negatives were indicated in 12 provinces, where 338,563 units were analyzed for anti- T.cruzi, 1298 units were reactive and 1108 (85.4%) were confirmed by the IFI test. This indicated a rate of Chagas positives of 0.33%.
Conclusions. Although the analysis covered arrived at 99.9% of the blood units, a small degree of infection risk for T. cruzi still remains. The cases of T. cruzi in donors oscillate between 0 and 50 per thousand. This rate is highest in Casanare with a concomitantly high risk for acquisition of transfusional Chagas. ot show negative false results.