Background: Primary immunodeficiencies are a group of about 400 diseases of genetic origin, they are considered as rare diseases. However, above 6 million people in the world would be affected, regardless of sex, age or geographical area. Few studies have been conducted in sub-Saharan Africa. The main objective of this study was to show existence of these diseases in West Africa and difficulties to manage it. The specific objectives were to identify the different clinical patterns of PI cases, to describe their biological phenotypes and to propose management. Method: A cross-sectional observational study over a period of 4 years and 2 months resulted in recruitment of children with either 2 or more signs among the 10 warning signs for PID or with signs described in the 10 recommendations for diagnosis of PID from African Society for Immunodeficiencies (ASID). Biological and immunological exploration were carried out in these patients. The diagnostic approach of PID for emerging countries according to the method of B. Admou and et al. was adopted. Results: 30 cases of PID were recorded. The sex ratio was 1; with a median age at diagnosis of 24 months. The most common clinical symptoms were respiratory infections, followed by digestive and then cutaneous manifestations. 10 children had immunological confirmation. One patient had genetic confirmation of WAS. The most common category of PID was syndromic PID. Management was limited, based mainly on antibiotic prophylaxis. The death of 5 patients was recorded. Conclusion: PI are a severe condition and certainly underestimated in Senegal. This is due to the lack of knowledge of these diseases by physicians but also to an insufficient access to diagnostic tools. The raising of the technical platform will allow better documentation of these diseases, and advocate for access to certain treatments such as immunoglobulins supplementation and bone marrow transplantation.
The occurrence of cardiac disease is multifactorial with two new risk factors, homocysteine and aPL [2, 3]. The cardiovascular system is one of the target organs of the aPLs. Indeed, aPLs are responsible for 40% of cases of coronary heart disease, valvular disease, intracavitary thrombosis, and 4-6% of cases of severe morbidity [2]. Among aPLs, anticardiolipids (aCLs) are an independent risk factor for myocardial infarction or cardiac arrest. Nevertheless, these cardiac events remain outside the criteria for defining APLS, which were updated in 2006 [1].
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/ β 0-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.
Background. - The aim of this study was to evaluate the efficacy of medical screening to retain blood donors in window period by comparing the seroprevalence of infectious agents (HIV, hepatitis B and C, syphilis) in deferred versus accepted blood donors.Materials and methods. - This prospective and transversal study was performed during 4 months in the National Blood Transfusion Center in Dakar (Senegal). We conducted a convenience sampling comparing the seroprevalence of infectious agents (HIV, HBsAg, HCV and syphilis) in deferred versus accepted blood donors after medical selection.Results. - In total, 8219 blood donors were included. Medical selection had authorized 8048 donors (97.92%) and deferred donors were 171 (2.08%). The prevalence of HIV was higher in the deferred than in accepted blood donors (1.75% vs. 0.05%) (P = 0.0003; OR = 35.91), as well as for HBsAg (12.87% vs. 7.35%) (P = 0.006; OR = 1.86). HCV antibodies were present in 0.71% of accepted blood donors and 0.58% in deferred blood donors (P = 0.65; OR = 0.82). Only accepted donors had brought the infection of syphilis (0.34%) (P = 0.56; OR = 0).Conclusion. - Medical selection is efficient to exclude blood donors at high risk of HIV transmission and to a lesser extent of HBV. However, current medical screening procedures do not allow us to exclude donors asymptomatic carriers of HCV and syphilis. (C) 2015 Elsevier Masson SAS. All rights reserved.
BACKGROUND:The aim of this study was to evaluate the efficacy of medical screening to retain blood donors in window period by comparing the seroprevalence of infectious agents (HIV, hepatitis B and C, syphilis) in deferred versus accepted blood donors. MATERIALS AND METHODS:This prospective and transversal study was performed during 4 months in the National Blood Transfusion Center in Dakar (Senegal). We conducted a convenience sampling comparing the seroprevalence of infectious agents (HIV, HBsAg, HCV and syphilis) in deferred versus accepted blood donors after medical selection. RESULTS:In total, 8219 blood donors were included. Medical selection had authorized 8048 donors (97.92%) and deferred donors were 171 (2.08%). The prevalence of HIV was higher in the deferred than in accepted blood donors (1.75% vs. 0.05%) (P=0.0003; OR=35.91), as well as for HBsAg (12.87% vs. 7.35%) (P=0.006; OR=1.86). HCV antibodies were present in 0.71% of accepted blood donors and 0.58% in deferred blood donors (P=0.65; OR=0.82). Only accepted donors had brought the infection of syphilis (0.34%) (P=0.56; OR=0). CONCLUSION:Medical selection is efficient to exclude blood donors at high risk of HIV transmission and to a lesser extent of HBV. However, current medical screening procedures do not allow us to exclude donors asymptomatic carriers of HCV and syphilis.
The size, structure and distribution of host populations are key determinants of the genetic composition of parasite populations. Despite the evolutionary and epidemiological merits, there has been little consideration of how host heterogeneities affect the evolutionary trajectories of parasite populations. We assessed the genetic composition of natural populations of the parasite Schistosoma mansoni in northern Senegal. A total of 1346 parasites were collected from 14 snail and 57 human hosts within three villages and individually genotyped using nine microsatellite markers. Human host demographic parameters (age, gender and village of residence) and co-infection with Schistosoma haematobium were documented, and S. mansoni infection intensities were quantified. F-statistics and clustering analyses revealed a random distribution (panmixia) of parasite genetic variation among villages and hosts, confirming the concept of human hosts as ‘genetic mixing bowls’ for schistosomes. Host gender and village of residence did not show any association with parasite genetics. Host age, however, was significantly correlated with parasite inbreeding and heterozygosity, with children being more infected by related parasites than adults. The patterns may be explained by (1) genotype-dependent ‘concomitant immunity’ that leads to selective recruitment of genetically unrelated worms with host age, and/or (2) the ‘genetic mixing bowl’ hypothesis, where older hosts have been exposed to a wider variety of parasite strains than children. The present study suggests that host-specific factors may shape the genetic composition of schistosome populations, revealing important insights into host–parasite interactions within a natural system.
Infection of the human host by schistosome parasites follows exposure of skin to free-swimming cercariae and is aided by the release of excretory/secretory (E/S) material, which is rich in proteases and glycoconjugates. This material provides the initial stimulus to cells of the innate immune system. The study presented here is the first to examine human innate/early immune responsiveness to cercarial E/S in subjects from an area co-endemic for Schistosoma mansoni and S. haematobium. We report that in infected participants, stimulation of whole-blood cultures with cercarial E/S material (termed 0-3 hRP) caused the early (within 24 h) release of greater quantities of regulatory IL-10, compared with uninfected controls. Elevated levels of IL-10 but not pro-inflammatory TNFα or IL-8 were most evident in participants co-infected with S. mansoni and S. haematobium and were accompanied by a higher 0-3 h RP-specific IL-10: TNFα ratio. We also report that glycosylated components within 0-3 h RP appear to be important factors in the stimulation of IL-8, TNFα and IL-10 production by whole-blood cells.
Despite significant progres on haemophilia care in developed world, this disease remains unknown in many sub-Saharan African countries. The objectives of this article were to report Senegalese experience on the management of haemophilia care through 18years of follow-up. This cohort study included 140 patients (127 haemophilia A, 13 haemophilia B), followed in Dakar's haemophilia treatment centre from 1995 to 2012. Our study reported a prevalence of 2.3/100000 male births, accounting for 11.6% of what is expected in Senegal. From the period 1995-2003 to 2004-2012, significant progress was seen including 67.9% increase in new patient's identification, 11.3years reduction in mean age at diagnosis (from 15.5 to 4.2years), lower mortality rate (from 15.3% to 6.8%) and age at death evolved from 6.5 to 23.3years. Of the 50 haemophilia A patients who were tested for inhibitor presence, 10 were positive (eight severe and two moderate) that is prevalence of 20%. All patients were low responders since inhibitor titre was between 1.5 and 3.8BU. Disabilities were seen in 36.5% of patients above 20years old who had musculoskeletal sequels and 39% had no scholar or professional activities in our setting. Implementing haemophilia care in sub-Saharan Africa is a great challenge as this disease is not yet counted in national health problems in many countries. Lessons learned from this study show a significant improvement in diagnosis and prognosis parameters. This emphasizes the needs to set up such follow-up initiatives and to enhance medical and lay cooperation for better results.
Numerous studies suggest that herpes simplex virus type 2 (HSV-2) increases the risk of HIV-1 infection but recent clinical trials of HSV-2 suppressive therapy failed to show an effect. We assessed the putative association between HSV-2 and HIV-1 in a population of HIV-concordant-negative, HIV-1-discordant and HIV-1-concordant-positive married couples from Dakar, Senegal. In agreement with previous studies, we observed a strong overall association between HSV-2 and HIV-1 (odds ratio 4.61; P < 0.001). However, this association was mainly determined by a low HSV-2 prevalence in HIV-concordant-negative couples compared with HIV-1-discordant and HIV-1-concordant-positive couples (23% versus 59% and 66%, respectively; P < 0.001). We observed no further differences in HSV-2 prevalence between HIV-1-discordant and HIV-1-concordant-positive couples (59% and 66%, respectively; P = 0.483). Neither the index (59% versus 62%, P = 1.000) nor recipient partners (41% versus 63%, P = 0.131) in HIV-1-discordant and HIV-1-concordant-positive couples showed significant differences in HSV-2 prevalence. HSV-2 does not constitute a clear risk factor for HIV-1 infection in this population.
PURPOSE:Chronic complications of sickle cell disease (SS) usually involve irreversible organ damage. Several genetic factors have been shown to have predicative value for chronic complications but these data are not always available. The purpose of this study was to assess the value of sociodemographic and clinicobiological features in predicting chronic complications.METHODS:This study included a total of 229 adult SS patients who underwent quarterly follow-up examinations for at least 10 years (range, 10 - 16). All sociodemographic and clinicobiological data were recorded. Screening for complications was performed at least once every three years. The risk of developing chronic complications was analyzed in function of patient follow-up data.RESULTS:Mean patient age was 28.6 years (range, 20 - 57) and sex ratio was 1.3. Prevalence of chronic complications was 34.9% (80/229). The most common complication was bone necrosis in 27 cases (11.7%) followed by gallstones in 24 (10.4%). The only sociodemographic factor with predictive value was patient age (p=0.0008). Multivariate analysis identified two clinicobiological factors with predictive value. History of transfusion was associated with a 3-fold higher risk while hemoglobin F level was associated with decreased risk.CONCLUSION:In this study, age and low hemoglobin F level were the only predictive factors of chronic complications in SS patients.
Background. - Malaria is a real public health problem in Africa; more than 300 million new cases and approximately two million deaths arise every year. In spite of the blood transfusion is a potential way of Plasmodium transmission, there is no consensus for measures to prevent post-transfusion malaria in endemic area. This work aimed at comparing some tools and to discuss various strategies to be implemented.Material and methods. - The study concerned 3001 blood donors recruited in seven blood transfusion centers in Senegal during two periods: dry season (June-July, 2003) and rainy season (October-November, 2003). We evaluated the efficiency of the selection questionnaire for the blood donors to exclude those who are potentially asymptomatic carriers of the Plasmodium. Every donation was screened for pLDH antigen and antibodies against Plasmodium by Elisa technique (DiaMed, Cressier sur Morat, Suisse), morphological tests was also performed, as well as the screening of HIV, HBs Ag, HCV Ab and syphilis.Results. - Median age of blood donors was of 27.7 years. Anti-Plasmodium antibodies prevalence was 65.3% and pLDH antigen was of 0.53%, all positivity was confirmed by microscopy. The prevalence of the other infectious markers was 11.7% for HBs Ag; 0.83% for syphilis; 0.49% for HCVAb and 0.46% For HIVAb. The risk factors associated with an asymptomatic carrier of Plasmodium were: the rainy season, irregular character of the blood donations, high frequency of malaria attacks in the past, and absence of treatment during the last episode.Conclusion. - Plasmodium represents the third risk of blood transmitted infectious agents after hepatitis B virus, syphilis, and before HCV and HIV in Senegal. The medical questionnaire is not useful enough for asymptomatic carriers deferral, and we propose to introduce Plasmodium screening. The screening for Plasmodium pLDH by Elisa technique seems to be the best tool in endemic area and the strategy of systematic screening is the most suited in terms of blood transfusion safety. (C) 2009 Elsevier Masson SAS. All rights reserved.
Summary: Alternative, affordable, and simple assays to monitor antiretroviral therapy (ART) in resource-poor settings are needed. We have evaluated and compared a heat-denatured (HD) HIV p24 amplified enzyme-linked immunosorbent assay from Perkin-Elmer and CD38+CD8+ T-cell levels, determined by flow cytometry, for their capacity to predict viral load (VL) in HIV-1-infected patients from Senegal. Median fluorescence intensity (MFI) of CD38 expression on memory (CD45RO+) CD8+ T cells correlated better with RNA VL than HD p24 antigenemia (R = 0.576, P < 0.0001 vs R = 0.548, P < 0.0001). MFI of CD38 expression on memory CD8+ T cells could predict detectable RNA VL (VL = 2.6 log10) with a sensitivity of 87% and a specificity of 74%. A comparable sensitivity (89%) could be reached for HD p24 assay, but only to predict RNA VL of more than 5 logs, which might lead to unacceptable delays in clinical decision making. The clinical use of the HD p24 assay to monitor ART in Senegal would require more comparative data about the kinetics of p24 antigen and HIV RNA in peripheral blood as well as further evaluation regarding its sensitivity toward subtype A and CRF02. MFI of CD38 expression on memory CD8+ T cells appeared to be a better alternative to monitor ART in HIV-infected patients from Senegal.
INTRODUCTIONHepatitis C virus (HCV) is an important problem of public health in the world according to its transmission mode and its pathogenesis. The risk of blood transmission has led to be the systematic screening of blood donors in the world. In Senegal no study about HCV prevalence on the general population and also has been done. The aim of our study was to determine HCV prevalence in blood donors and the rate of co-infection with hepatitis B (HCV/HBV) or with HIV infection (HCV/HIV).MATERIALS AND METHODSThis study had been done in the National Blood Transfusion Centre (CNTS) in Dakar. Two different techniques has been used for the assessment HCV: 1/ ELISA technique and 2/ Immunoblot RIBA as confirmation test.RESULTSOur study relates to 1565 blood donors recruited in CNTS during 2002. 369 of them were new blood donors with 365 females and 1200 males. The mean average was 30.5 +/- 9.5 years, ranged from 18 to 59 years. HCV ELISA test were positive in 22 plasma samples and one of them were co-infected with hepatitis B (HCV/HBV). Four out of these 22 samples have been confirmed positive to RIBA test and three of them were not determined. HCV seroprevalence were 1.4% after ELISA and 0.25% after RIBA testing. This seroprevalence were similar in male and in female and higher in new blood donors than in regular blood donors.CONCLUSIONOur results reinforce the necessity to screen hepatitis C virus in all Senegalese blood transfusion centres.
Flow cytometry is an accurate but expensive method to determine absolute CD4 cell counts. We compared different methods to measure absolute CD4 counts in blood samples from HIV-infected and uninfected subjects using a research/clinical flow cytometer (FACScan); a dedicated clinical instrument (FACSCount); and a volumetric, mobile, open-system flow cytometer equipped with 3 fluorescence and 2 light scatter detectors (Cyflow SL blue). The FACScan and Cyflow were used as single-platform instruments, but they differ in running cost, which is a central factor for resource-poor settings. Direct volumetric and bead-based CD4 measurements on the Cyflow were compared with 2 bead-based single-platform CD4 measurements on the FACSCount and on FACScan (TruCount) in "Le Dantec" Hospital, Dakar, Senegal, using whole blood samples from 102 HIV+ and 28 HIV- subjects. The agreement between the various measurement methods was evaluated by Bland-Altman analysis. Volumetric CD4 measurements on the Cyflow using a no-lyse-no-wash (NLNW) procedure and a lyse-no-wash (LNW) procedure correlated well with each other (R2 = 0.98) and with CD4 measurements on the FACSCount (R2 = 0.97) and FACScan (R2 = 0.97), respectively. Red blood cell lysis had no negative effect on the accuracy of absolute CD4 counting on the Cyflow. An excellent correlation was observed between bead-based CD4 measurements on the Cyflow and CD4 measurements on the FACSCount (R2 = 0.99) and FACScan (R2 = 0.99). Rigid internal and external quality control monitoring and adequate training of technicians were considered essential to generate accurate volumetric CD4 measurements on the Cyflow.
Twelve HIV-1-infected, nine HIV-2-infected patients and eight HIV-negative subjects were given a 40IU booster dose of tetanus toxoid (TT). Blood was collected on days 0, 7 and 30 after immunization. Changes in HIV-1 or HIV-2 RNA load were evaluated by nested PCR. TT-IgG antibody levels were quantified by ELISA. CD4 cell counts as well as activation, memory and maturation markers of T lymphocyte subsets were determined by flow cytometry. The induction of apoptosis was investigated using 7-aminoactinomycin D (AAD) and propidium iodide (PI) staining. Proliferative responses to TT and pokeweed mitogen (PWM) were determined by the level of [3H] thymidine incorporation. Seven and 30 days after immunization, there was no detectable increase in HIV-1 or HIV-2 plasma load. There were also no changes in CD4 cell counts, CD69, HLA-DR and memory CD45RO or naive CD45RA antigens. Immunization did not increase the spontaneous apoptosis of peripheral blood mononuclear cells (PBMCs), CD4+ and CD8+ T cells subsets neither in controls nor in HIV-infected patients. Similarly, apoptosis induced in vitro by PWM or by the specific TT recall antigen did not vary during the study period. The proliferative response to PWM and to the TT recall antigen was decreased both in HIV-1- and HIV-2-infected patients compared to HIV-negative controls. Immunization significantly increased the TT-IgG levels in healthy controls and in HIV-infected patients. However, the anti-TT-IgG response, as measured by the fold-increase index between days 0 and 30, was significantly higher in healthy controls than in HIV-1- (P=0.036) and HIV-2-infected patients (P=0.003). In conclusion, we found no deleterious immunologic or virologic effect was detected in healthy HIV-1- and HIV-2-infected individuals after antigenic challenge with a TT booster. However, the response to TT vaccination was lower in HIV-1- and in HIV-2-infected individuals than in healthy HIV-negative controls.