[Molecular biology and transfusional viral safety]

Improvement of blood transfusion safety using the chemiluminescence technique for viral marker screening of blood donors in sub Saharan Africa

INTRODUCTION

Sub-Saharan Africa struggles continuously with insufficient resources and inadequate infrastructure that hinder the establishment of a safer blood supply despite improvements in transfusion safety over recent decades. This study aimed to evaluate the impact of the chemiluminescence technique in combination with immunoenzymatic and immunochromatographic tests for viral marker screening of hepatitis B (HBV), hepatitis C (HCV) and human immunodeficiency virus (HIV) in donated blood in a country of sub-Saharan Africa.

METHOD

This study was conducted in a population of 113,406 blood donors at the National Centre of Blood Transfusion in Senegal. The data were obtained from the 'INLOG' software and donor registers. Statistical analyses used Excel 2010 and Epi Info v6. Screening for HBsAg viral markers, anti-HCV Ab, HIV p24 Ag, anti-HIV1 and anti-HIV2 antibodies were first carried out using the chemiluminescence technique. Blood donations screened positive for HBV or HCV were retested in a second chemiluminescence equipment. HIV-positive donations and their controls were subjected to solid phase immunochromatographic and indirect enzyme immunoassay techniques.

RESULTS

The prevalence among donors of HBV was 8.39 %, 0.56 % for HCV and 0.18 % for HIV. Of the donors tested positive for HIV in screenings and in doubled-controls, only 61.54 % were confirmed by the alternative tests; 34.02 % were negative and 4.44 % discordant between the three techniques.

CONCLUSION

This study shows the importance of introducing the chemiluminescence technique in association with serological screening of transfusion-transmitted viruses to improve blood supply safety in low-income countries.

Including polymerase chain reaction in screening for hepatitis C virus RNA in blood donations is not cost-effective

BACKGROUND AND OBJECTIVES

To assess the cost and effectiveness of adding a system of polymerase chain reaction (PCR) testing to the current enzyme-linked immunosorbent assay (ELISA) screening for hepatitis C virus (HCV) in blood donations.

MATERIALS AND METHODS

We performed a cost-effectiveness analysis comparing three HCV screening strategies in French blood donors: detection of antibodies against HCV by an ELISA on blood donations (the current policy) vs. ELISA and PCR either on each blood donation or on blood pools. We combined national surveillance data on HCV antibody-positive blood donors with a literature review in a Markov model for natural history of HCV disease and its treatment.

RESULTS

PCR testing performed in parallel with ELISA will potentially add less than 1 year of life for all French recipients compared to ELISA screening alone. The incremental costs per life year saved were, respectively, epsilon84.6 million with ELISA and PCR testing of blood pools, and epsilon891.1 million with testing of individual blood donations.

CONCLUSION

PCR testing performed in parallel with antibody screening, either on pools or on single donations is not currently a cost-effective option for the detection of HCV RNA virus in blood donors.