Le dépistage biologique de la syphilis chez le donneur de sang d’Afrique subsaharienne : quelle stratégie ?

Syphilis screening practices in blood transfusion facilities in Ghana

OBJECTIVES

The primary objective of this study was to compare laboratory practices for screening blood donors for syphilis at blood transfusion facilities in Ghana with the recommendations of the World Health Organization and the National Blood Service, Ghana (NBSG). The prevalence of syphilis antibodies in blood donors in Ghana was also estimated.

METHODS

Over an 11-month period, from February 2014 to January 2015, a semi-structured questionnaire was administered to 122 laboratory technical heads out of a total of 149 transfusion facilities in Ghana. The response rate was 81.9%.

RESULTS

A total of 58 (48%) transfusion facilities tested donors for syphilis, with an estimated 3.7% seroprevalence (95% confidence interval 3.6-3.8%). A total of 62782 out of 91386 (68.7%) donations were tested with assays that are not recommended. The estimated syphilis seroprevalence in voluntary donations was 2.9%, compared to 4.0% in family donations (p=0.001). Only 6.9% of the health facilities were using standard operating procedures (SOPs).

CONCLUSIONS

Despite international and national recommendations, more than half of the studied health facilities that provide blood transfusions in Ghana are not screening blood donations for syphilis. These data show a considerable mismatch between recommendations and practice, with serious consequences for blood safety and public health.

The use of rapid diagnostic tests for transfusion infectious screening in Africa: a literature review

Infectious risk associated with blood transfusion remains a major public health challenge in Africa, where prevalence rates of the major transfusion-transmissible infections (ie, hepatitis B, hepatitis C, human immunodeficiency virus, and syphilis) are among the highest in the world. Resource-limited blood services often operate with minimal predonation screening safeguards, prompting exclusive reliance on laboratory testing to mitigate infectious risk. Transfusion screening with rapid diagnostic tests (RDTs) has been adopted in areas that lack the capacity to support the routine use of more sophisticated technologies. However, uncertainty surrounding the performance of some RDTs in the field has spurred debate regarding their application to blood donation screening. Our review of the literature identified 17 studies that evaluated RDTs for the infectious screening of blood donors in Africa. The review highlights the variable performance of available RDTs and the importance of their use in a quality-assured manner. Deficiencies in performance observed with some RDTs underscore the need to validate test kits prior to use under field conditions with locally acquired samples. Suboptimal sensitivities of some available tests, specifically hepatitis B virus rapid assays, question their suitability in single-test algorithms, particularly in high-prevalence regions. Although RDTs have limitations, many of which can be addressed through improved training and quality systems, they are frequently the only viable option for infectious screening in resource-poor African countries. Therefore, additional studies and specific guidelines regarding the use of RDTs in the context of blood safety are needed.