[Alloimmunisation in polytransfused patients with non-phenotyped red blood cells at the University Hospital Souro Sanou of Bobo Dioulasso (Burkina Faso)]. / Allo-immunisation chez les patients polytransfusés avec des concentrés de globules rouges non phénotypés au Centre Hospitalier Universitaire Souro Sanou de Bobo Dioulasso (Burkina Faso).

Introduction: in Burkina Faso, blood transfusion is carried out with only ABO and RHD compatibility between the donor and the recipient. Such a practice carries risks of alloimmunisation, which can lead to clinical complications especially in polytransfused patients. The objective is to determine the prevalence and factors associated with alloimmunisation in polytransfused patients with non-phenotyped red blood cells at Souro Sanou University Hospital. Methods: we conducted a cross-sectional study in polytransfused patients in the clinical departments of the University Hospital Souro Sanou over a 3-month period (March to May 2019). In each of the 141 patients included, 5 ml of whole blood was collected in an ethylenediaminetetraacetic acid (EDTA) tube for testing for irregular antibodies. Irregular antibody testing was performed using the indirect Coombs gel filtration technical. Results: in total, the frequency of alloimmunisation obtained was 5.67%. The majority of the antibodies identified belonged to the Rhesus systems and Kell. We found no statistically significant relationship between age, sex, disease history, number of bags transfused and the positivity of the Irregular Antibody test (p = 0.37, p = 0, 75, p = 0.96). Conclusion: we found that the risk of alloimmunisation is major. Additional measures should be taken to strengthen the immunological safety of transfusions in Burkina Faso. We propose that in Burkina Faso, anti-globulin compatibility testing should be performed systematically in patients with a high risk of immunisation.

[Humoral response to Plasmodium falciparum antigenic peptides (MSP1, MSP2, and SR-11.1) in subjects living in endemic areas]. / La réponse humorale contre les peptides antigéniques de Plasmodium falciparum (MSP1, MSP2 et SR-11.1) chez des sujets vivant en zone endémique.

Introduction: vaccines are the key tools for controlling and eradicating malaria worldwide. Currently, research and development are focused on three types of vaccine candidates that target different life stages of Plasmodium falciparum in humans and the vector. The purpose of this study is to evaluate the humoral response to Plasmodium falciparum antigenic peptides (MSP1, MSP2 and SR-11.1) in subjects living in endemic areas. Methods: we conducted a cross-sectional study of serum samples collected from 182 Vietnamese subjects living in endemic areas over a period of 5 months. Whole blood was centrifuged and the serum was aliquoted into cryovials and preserved at -20°C until IgG testing. ELISA was used for total immunoglobulin G (IgG) antibodies testing after peptide coupling with glutaraldehyde. Results: a total of 182 sera samples from Vietnamese subjects living in endemic areas were included. In the different study age groups, total antigen-specific IgG antibodies against Plasmodium falciparum antigenic peptides (MSP-1; MSP-2 and SR-11.1) showed age-dependent distribution. In subjects aged 3-19 years, the level of total antigen-specific IgG antibodies against Plasmodium falciparum were lower than those of the age groups over 20 years of age (p=0.07). Comparison of specific antigen-specific IgG antibody levels with Plasmodium falciparum antigenic peptides MSP-1, MSP-2, and SR-11.1 in the age groups showed a significantly higher mean in MSP-1 and MSP-2 compared to anti-SR-11.1 (p=0.04). Conclusion: this study highlights that the level of specific antibodies against Plasmodium falciparum antigenic peptides (MSP-1; MSP-2 and SR-11.1) is age dependent. Of the three antigenic peptides, MSP-1 and MSP-2 appear to be more immunogenic than SR.11.1. Therefore, SR.11.1 is a macromolecule to the immune system and, from this point of view, appears to be significantly less immunogenic than other peptides.

Residual risk of HIV, HCV, and HBV transmission by blood transfusion between 2015 and 2017 at the Regional Blood Transfusion Center of Ouagadougou, Burkina Faso.

INTRODUCTION: In sub-Saharan Africa, the high endemicity of blood-borne infections is a serious threat to transfusion safety. In order to improve transfusion safety, Burkina Faso has undertaken in recent years a reorganization of its blood-transfusion system through the creation of a National Blood Transfusion Center, which is the only blood operator in the whole country. This study aimed to estimate the residual risk of transmission of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) by blood transfusion at the Regional Blood Transfusion Center (RBTC) of Ouagadougou. METHODS: This was a retrospective study conducted at the RBTC of Ouagadougou between 2015 and 2017. Prevalence of infectious markers was calculated for first-time donors and incidence rates calculated for repeat donors who had made at least two donations of blood over the study period. Residual risks were estimated for the three viruses (HIV, HBV, and HCV) by multiplying the incidence rate per 100,000 person-years by the respective durations of serological windows. RESULTS: Between 2015 and 2017, of a total of 84,299 blood donors, 68,391 (81.13%) were first-time donors compared to 15,908 (18.87%) repeat donors. The seroprevalence of HBV (8.56%) was twice that of HCV (4.40%) and fourfold that of HIV (1.80%). Incidence rates were 1,215, 2,601, and 1,599 per 100,000 donations for HIV, HCV, and HBV, respectively. In contrast, the estimated residual risk for HCV (1 in 213 donations) was double that of HBV (1 in 408 donations) and four times that of HIV (1 in 1,366). CONCLUSION: The residual risk of transmission of these viruses by blood transfusion remains high in repeat donors. An effective donor-retention and education policy could help to reduce this residual risk.