Importance of extending the use of polymerase chain reaction in the diagnosis of venereal syphilis in a blood transfusion center in Burkina Faso, West Africa

Introduction

Due to the existence of a variety of types of non-venereal syphilis caused by the related T. pallidum, regular serological testing such as Rapid Plasma Reagin (RPR) and Chemiluminescent Microparticle Immunoassay Technique (CMIA) are often unable to differentiate venereal syphilis from the non- venereal one, hence, the interest in the use of molecular biology testing for a confirmation diagnosis of syphilis caused by Treponema pallidum subspecies pallidum.

Objective

The study is designed to assess the effectiveness of PCR testing and serological methods in the diagnosis of Treponema pallidum subsp pallidum among blood donors in Burkina Faso.

Methodes

The study included 6375 samples of volunteer blood donors from the regional blood transfusion center of Ouagadougou (CRTS/O). Among samples, 183 positive and 59 negative in RPR were analyzed to detect antibodies anti-T. pallidum subsp pallidum with a immunoassay method (CMIA) and were confirmed using the Polymerase Chain Reaction testing.

Results

In RPR, we obtained a prevalence rate of 2.9% (183/6375) for treponematosis. From the 183 RPR+ specimen, 108 (59%) were found CMIA+ and 11 (6%) were confirmed PCR+. While the 59 pattern RPR-; 31 (52.5%) were CMIA + including 3 (5.1%) tested PCR+. Seventy-five (75) samples RPR + /CMIA-; 2 (2.7%) were confirmed positive by PCR. All 28 samples RPR-/CMIA- were confirmed negative by PCR.

Conclusion

PCR testing confirmed a low distribution of T. pallidum subsp pallidum in comparison to serological methods. Cross-reactions, existence of non-venereal treponemal or immunological scars could account for the discrepancy between the results obtained.

[Implementation of hemovigilance in Sub-Saharan Africa]

PURPOSE OF THE STUDY

Hemovigilance being an essential part of blood transfusion safety, many countries have set legislation for its organization and its establishment. In Sub-Saharan Africa, where transfusion practice is facing many challenges, hemovigilance does not always appear as a priority. Nevertheless, in 2000, Burkina Faso decided to reorganize its blood transfusion system according to the World Health Organisation recommendations and other international standards. A national blood transfusion center and regional blood transfusion centers were created. From 2005 to 2009, a hemovigilance pilot project was conducted by the regional blood transfusion center of Bobo-Dioulasso.

METHODS

The implementation of this hemovigilance project included the following steps: training of medical and paramedical personnel of the health facilities provided with blood and blood products by the regional blood transfusion center, distribution of post transfusion and hemovigilance forms, and the creation of a hemovigilance and transfusion committee.

RESULTS

During the period 2005-2009, 34,729 blood products were distributed for 23,478 patients. The return rate of the post-transfusion and hemovigilance forms (number of files completed partially or completely and returned to the regional blood transfusion center compared to the number of units distributed) raised from 83.1 to 94.8%, the rate of traceability (rate of forms returned to the regional blood transfusion center and totally completed) raised from 71.6 to 91.6%, and the concordance between the patient for which the blood was delivered and the patient transfused moved from 92.9 to 98.0%. The notification rate of transfusion incidents raised from 1.1 to 16.1 per 1000 units transfused during that period.

CONCLUSION

The implementation of a hemovigilance system is possible in the Sub-Sahara African countries. This constitutes a major element in the improvement of different steps of transfusion safety. The implementation of a hemovigilance system requires negotiations between transfusion centers and the hospital personnel, and should be facilitated by the official regulation on blood transfusion practices.