[Evaluation of the efficacy of medical screening of blood donors on preventing blood transfusion-transmitted infectious agents]

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.

Hepatitis B in Senegal: A Successful Infant Vaccination Program but Urgent Need to Scale Up Screening and Treatment (ANRS 12356 AmBASS survey)

Senegal introduced the infant hepatitis B virus (HBV) vaccination in 2004 and recently committed to eliminating hepatitis B by 2030. Updated epidemiological data are needed to provide information on the progress being made and to develop new interventions. We estimated the prevalence of hepatitis B surface antigen (HBsAg) in children and adults living in rural Senegal and assessed hepatitis B treatment eligibility. A cross-sectional population-based serosurvey of HBsAg was conducted in 2018-2019 in a large sample (n = 3,118) of residents living in the Niakhar area (Fatick region, Senegal). Individuals positive for HBsAg subsequently underwent clinical and biological assessments. Data were weighted for age and sex and calibrated to be representative of the area's population. Among the 3,118 participants, 206 were HBsAg positive (prevalence, 6.9%; 95% confidence interval [CI], 5.6-8.1). Prevalence varied markedly according to age group in individuals aged 0-4, 5-14, 15-34, and ≥35 years as follows: 0.0% (95% CI, 0.00-0.01); 1.5% (95% CI, 0.0-2.3); 12.4% (95% CI, 9.1-15.6); and 8.8% (95% CI, 6.1-11.5), respectively. Of those subsequently assessed, 50.9% (95% CI, 41.8-60.0) had active HBV infection; 4 (2.9%; 95% CI, 0.9-9.4) were eligible for hepatitis B treatment. Conclusion: In this first population-based serosurvey targeting children and adults in rural Senegal, HBsAg prevalence was very low in the former, meeting the World Health Organization's (WHO) < 1% HBsAg 2020 target; however, it was high in young adults (15-34 years old) born before the HBV vaccine was introduced in 2004. To reach national and WHO hepatitis elimination goals, general population testing (particularly for adolescents and young adults), care, and treatment scale-up need to be implemented.

Efficacy of Blood Donor Selection: Comparing Sero-Prevalence of Transfusion-Transmissible Infections Among Eligible and High-Risk Behavior Deferred Donors in Iran

Background: Eliminating high-risk individuals has a special role in ensuring blood safety. Due to epidemiological, demographic, and even cultural changes in each country, this process should be continuously evaluated and reviewed, if necessary. Objectives: This study aimed to evaluate the impact of the current donor selection procedure on blood safety in Iran. Methods: A total of 2,525 high-risk deferred donors who were referred between 2018 and 2019 were evaluated regarding hepatitis B surface antigen, hepatitis C virus antibody, and human immunodeficiency virus antigen and antibody. All repeatedly reactive samples were evaluated by confirmatory tests. Characteristics' parameters, donor status, and TTI marker rates of the participants and 1,315,871 eligible donors in the indicated period obtained from the national database on blood donors, were compared. Data were analyzed using SPSS version 24.0. Results: The prevalence of HBV, HCV, and HIV in 100,000 deferred donors was 1148, 515, and 119, respectively. This prevalence was 26, 28, and 33-times higher than the eligible donors, respectively. Unlike HBV, its prevalence among males was almost twice that of females among the deferred group. In the eligible group, females had a higher prevalence for HBV and HCV as compared to males. The HCV and HBV (6.7 and 4.3-fold) among deferred first-time donors had a significantly higher prevalence compared with the eligible first-time donors (P‐value < 001). Notably, the higher was the education degree, the lower was the prevalence of infection in both groups. Conclusions: Current deferral criteria and donor selection procedure in Iran are an opportunity to eliminate high-risk individuals from the blood donation.

Trends of blood-borne infectious diseases in a rural blood donation center of southeast Gabon (Koula-Moutou)

Introduction

Blood-borne pathogens such as human immunodeficiency virus (HIV), hepatitis B and C (HBV and HCV) viruses and Treponema pallidum remain a major public health problem in sub-Saharan Africa. The purpose of this study was to assess the frequency and clinical implications of HIV, HBV, HCV and Treponema pallidum markers in blood donors in a rural area of Southeast Gabon (Koula-Moutou) from 2012 to 2017.

Methods

Hepatitis B surface antigen (HBsAg), anti-HIV, anti-HCV and anti-Treponema pallidum antibodies were screened using rapid diagnostic tests (RDTs).

Results

Of a total of 5,706 blood donors, 1,054 (18.5%) were seropositive for at least one infectious marker and 59 (5.6%) had serologic evidence of multiple infections. The overall seroprevalence of HIV, HBsAg, HCV, and syphilis was 3.1%; 5.9%; 6.2% and 3.3%, respectively. HIV, syphilis and HCV distributions were associated with neither the sex nor the age of the donors. Only HBsAg seroprevalence was significantly higher in donors of the age group 26-35 years old compared to donors of the age group 36-45 years (OR = 1.43 (95% CI: 1.01-2.04), P = 0.045). There was a significant increase in the frequencies of HIV and syphilis and a regression of HBsAg and HCV among blood donors.

Conclusion

This study presents the epidemiology of the main pathogens detected in blood donors in a rural area in Gabon. We found that the overall distribution of transfusion transmitted infectious diseases were lower than those observed in the general population but could be underestimated due to the use of RDTs in the screening process of the blood donations.

Impact of Multiplex PCR in Reducing the Risk of Residual Transfusion-Transmitted Human Immunodeficiency and Hepatitis B and C Viruses in Burkina Faso

Background and Objective

The improved performance of serological tests has significantly reduced the risk of human immunodeficiency and hepatitis B and C viruses transmission by blood transfusion, but there is a persistence of residual risk. The objective of this study was to evaluate the impact of multiplex PCR in reducing the risk of residual transmission of these viruses in seronegative blood donors in Burkina Faso.

Methods

This cross-sectional study was conducted from March to September 2017. The serological tests were performed on sera using ARCHITECT_SRi1000 (Abbot diagnosis, USA). Detection of viral nucleic acids was performed by multiplex PCR on mini-pools of seronegative plasma for HBV, HCV and HIV using SaCycler-96 Real Time PCR v.7.3 (Sacace Biotechnologies). Multiplex PCR-positive samples from these mini-pools were then individually tested by the same method.

Results

A total of 989 donors aged 17 to 65 were included in the present study. “Repeat donors” accounted for 44.79% (443/989). Seroprevalences for HIV, HBV, and HCV were 2.53% (25/989), 7.28% (72/989) and 2.73% (27/989), respectively. Of the 14 co-infections detected, HBV/HCV was the most common with 0.71% (7/989) of cases. Of 808 donations tested by multiplex PCR, 4.70% (38/808) were positive for HBV while no donation was positive for HIV or HCV.

Conclusion

Our study showed a high residual risk of HBV transmission through blood transfusion. Due to the high prevalence of blood-borne infections in Burkina Faso, we recommend the addition of multiplex PCR to serologic tests for optimal blood donation screening.

An Original Approach to Evaluating the Quality of Blood Donor Selection: Checking Donor Questionnaires and Analyzing Donor Deferral Rate

Blood donor selection is a cornerstone for blood transfusion safety, designed to safeguard the health of both donors and recipients. In the Service du Sang, Belgian Red Cross, French and German-speaking part of Belgium (SFS), health professionals (HPs) are allowed to interview donors on their own after formal qualification. This qualification is afterward evaluated by means of two complementary quality indicators: monitoring of donor health questionnaires (DHQs) and analysis of donor deferral rate. The study aims to evaluate the degree to which both quality indicators may be useful and appropriate tools to evaluate the quality of blood donor selection. An analysis performed on 2016 data showed that noncompliance detected by means of DHQ monitoring seems to be more frequent in HPs who conduct a low number of interviews compared to all HPs as a group (5.67 vs. 3.23%; p < 0.001). Deferral rates are also higher in HPs with a lower activity compared to HPs who interview more donors (14.80 vs. 13.00%, p < 0.001). Furthermore, statistically differences are observed between the type of blood donation venue in terms of the global deferral rate (for instance fixed site vs. schools: 11.9 vs. 19.5%; p < 0.001), and specific reasons for deferral (such as sexual risk behavior and travel in at-risk areas, the differences being highly significant between each category of blood donation venue; p < 0.001). Providing the HPs with feedback on these findings was an opportunity to draw their attention to some aspects of the selection process in order to improve it.

Sickle cell disease

Sickle cell disease is a common and life-threatening haematological disorder that affects millions of people worldwide. Abnormal sickle-shaped erythrocytes disrupt blood flow in small vessels, and this vaso-occlusion leads to distal tissue ischaemia and inflammation, with symptoms defining the acute painful sickle-cell crisis. Repeated sickling and ongoing haemolytic anaemia, even when subclinical, lead to parenchymal injury and chronic organ damage, causing substantial morbidity and early mortality. Currently available treatments are limited to transfusions and hydroxycarbamide, although stem cell transplantation might be a potentially curative therapy. Several new therapeutic options are in development, including gene therapy and gene editing. Recent advances include systematic universal screening for stroke risk, improved management of iron overload using oral chelators and non-invasive MRI measurements, and point-of-care diagnostic devices. Controversies include the role of haemolysis in sickle cell disease pathophysiology, optimal management of pregnancy, and strategies to prevent cerebrovascular disease.

Efficacy and Safety of Manual Partial Red Cell Exchange in the Management of Severe Complications of Sickle Cell Disease in a Developing Country

Introduction

The realization of red cell exchange (RCE) in Africa faces the lack of blood, transfusion safety, and equipment. We evaluated its efficacy and safety in severe complications of sickle cell disease.

Patients and Method

Manual partial RCE was performed among sickle cell patients who had severe complications. Efficacy was evaluated by clinical evolution, blood count, and electrophoresis of hemoglobin. Safety was evaluated on adverse effects, infections, and alloimmunization.

Results

We performed 166 partial RCE among 44 patients including 41 homozygous (SS) and 2 heterozygous composites SC and 1 S/β0-thalassemia. The mean age was 27.9 years. The sex ratio was 1.58. The regression of symptoms was complete in 100% of persistent vasoocclusive crisis and acute chest syndrome, 56.7% of intermittent priapism, and 30% of stroke. It was partial in 100% of leg ulcers and null in acute priapism. The mean variations of hemoglobin and hematocrit rate after one procedure were, respectively, +1.4 g/dL and +4.4%. That of hemoglobin S after 2 consecutive RCE was −60%. Neither alloimmunization nor viral seroconversion was observed.

Conclusion

This work shows the feasibility of manual partial RCE in a low-resource setting and its efficacy and safety during complications of SCD outside of acute priapism.

[Prevalence of hepatitis B surface antigen and its associated factors in Senegalese military personnel sent on mission to Darfur]

Introduction

Au Sénégal, 85% de la population adulte ont été en contact avec le virus de l'hépatite B et environ 11% sont porteurs chroniques de l'antigène de surface de ce virus (AgHBs). Cette infection est peu documentée dans l'armée sénégalaise. L'objectif de cette étude était d'évaluer la prévalence de l'AgHBs chez des militaires sénégalais envoyés en mission au Darfour (Soudan) et d'identifier les facteurs associés.

Méthodes

Nous avons mené une étude transversale du 1^er juillet 2014 au 31 juillet 2014 chez des militaires sénégalais en mission au Darfour. La recherche de l'AgHBs a été effectuée dans le sérum des participants par la méthode immunochromatographique. La recherche de facteurs associés a été réalisée à l'aide d'une régression logistique multivariée.

Résultats

Notre étude a porté sur 169 militaires de sexe masculin. L'âge moyen était de 36,6 ans ± 9,5. Des antécédents d'hépatopathie chronique au niveau familial, d'exposition sanguine et d'exposition sexuelle ont été retrouvés respectivement chez 12,4% ; 24,9% et 45,6% de la population d'étude. L'AgHBs a été retrouvé chez 24 participants [14,2% (IC95% = 8,9-19,5)]. Après ajustement sur les facteurs de confusion potentiels, l'âge (OR=0,9 IC95% =0,9-1,0), un niveau d'étude universitaire (OR= 9,5 IC95% =1,3-67,1) et l'exposition sexuelle (OR=3,3; IC95% =1,0-10,3) étaient apparus associés de façon indépendante à l'hépatite B.

Conclusion

Notre étude retrouve une prévalence élevée de l'AgHBs et souligne la nécessité d'une évaluation plus poussée de l'hépatite B chez cette population.

HIV infection, viral hepatitis and liver fibrosis among prison inmates in West Africa

Background

Prisoners represent a vulnerable population for blood-borne and sexually transmitted infections which can potentially lead to liver fibrosis and ultimately cirrhosis. However, little is known about the prevalence of liver fibrosis and associated risk factors among inmates in sub-Saharan Africa.

Methods

Screening of liver fibrosis was undertaken in a randomly selected sample of male inmates incarcerated in Lome, Togo and in Dakar, Senegal using transient elastography. A liver stiffness measurement ≥9.5 KPa was retained to define the presence of a severe liver fibrosis. All included inmates were also screened for HIV, Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) infection. Substances abuse including alcohol, tobacco and cannabis use were assessed during face-to-face interviews. Odds Ratio (OR) estimates were computed with their 95 % Confidence Interval (CI) to identify factors associated with severe liver fibrosis.

Results

Overall, 680 inmates were included with a median age of 30 years [interquartile range: 24–35]. The prevalence of severe fibrosis was 3.1 % (4.9 % in Lome and 1.2 % in Dakar). Infections with HIV, HBV and HCV were identified in 2.6 %, 12.5 % and 0.5 % of inmates, respectively. Factors associated with a severe liver fibrosis were HIV infection (OR = 7.6; CI 1.8–32.1), HBV infection (OR = 4.8; CI 1.8–12.8), HCV infection (OR = 52.6; CI 4.1–673.8), use of traditional medicines (OR = 3.7; CI 1.4–10.1) and being incarcerated in Lome (OR = 3.3; CI 1.1–9.8) compared to Dakar.

Conclusions

HIV infection and viral hepatitis infections were identified as important and independent determinants of severe liver fibrosis. While access to active antiviral therapies against HIV and viral hepatitis expands in Africa, adapted strategies for the monitoring of liver disease need to be explored, especially in vulnerable populations such as inmates.