Prevalence of occult hepatitis B virus infection among blood donors in Ouagadougou, Burkina Faso

Background: In Burkina Faso, the polymerase chain reaction (PCR) assay is not routinely used in the biological qualification of blood donations and this constitutes a risk factor for the transmission of occult hepatitis B virus (HBV) infection during blood transfusion. The objective of this study is to determine the prevalence of occult B infection (OBI) among blood donors for the purposes of improved blood safety in Burkina Faso. Methodology: A descriptive cross-sectional study of 300 HBsAg negative blood donors was conducted in the city of Ouagadougou, Burkina Faso from April to October 2020. Anti-HBc antibody was determined using the BOSON® brand rapid tests. HBV DNA was detected in 75 selected donors by real-time PCR (rt PCR) using the 7500 Fast Real Time PCR assay technique. Results: Of the 300 HBsAg negative donors, 208 (69.3%) were males while 92 (30.7%) were females, with average age of 30.18 years. Anti-HBc antibody was detected in 39 cases (13%). Of the 75 donor samples tested by rt PCR, 3 (4%) were positive for HBV DNA (occult B infection); 2 of which were anti-HBc antibody positive (seropositive OBI) while 1 was anti-HBc antibody negative (seronegative OBI). Conclusion: Given the prevalence of OBI of 4% in this study and its consequences in blood recipients, it appears necessary that in addition to the classic serological markers of hepatitis B, to test for the presence of HBV DNA among blood donors in order to improve transfusion safety. Keywords: Prevalence, Occult B infection; Blood donors, Ouagadougou.   French title: Prévalence de l'infection occulte par le virus de l'hépatite B chez les donneurs de sang à Ouagadougou, Burkina Faso Contexte: Au Burkina Faso, la polymérase chain réaction (PCR) n’est pas utilisée lors de la qualification biologique des dons et cela constitue un facteur de risque de transmission de l’Infection Occulte du virus B (VHB) lors des transfusions sanguines. L’objectif de cette étude était de déterminer la prévalence de l’infection occulte B chez les donneurs de sang en vue d’une meilleure sécurité transfusionnelle. Méthodologie: Une étude transversale prospective, réalisée d’avril à octobre 2020 dans la ville de Ouagadougou incluant 300 donneurs de sang AgHBs négatif. L’anticorps anti HBc a été déterminé par les tests rapides de marque BOSON®. L’ADN du VHB a été recherché chez 75 donneurs par PCR en temps réel (rt PCR) avec le 7500 Fast Real Time PCR. Résultats: Parmi les 300 donneurs AgHBs négatifs, 208 (69,3%) étaient des hommes et 92 (30,7%) des femmes. L’âge moyen était de 30,18 ans. La recherche de l’Ac anti-HBc était positive dans 39 cas (13 %). Parmi les 75 échantillons passés à la rt PCR, 3 (4%) étaient positifs pour l’ADN du VHB. Sur les 3 cas d’ADN VHB positifs, 2 (66,67%) étaient positifs Ac anti HBc et 1 (33,33%) Ac anti HBc négatif. Conclusion: Compte tenu de la prévalence de l’infection occulte B et ses conséquences chez les donneurs de sang et chez les receveurs, il devient nécessaire de rechercher, en plus des marqueurs sérologiques classiques de l’hépatite B, l’ADN VHB pour une meilleure sécurité transfusionnelle. Mots clés: Prévalence, Infection occulte de l’HBV, Donneurs de sang, Ouagadougou &nbsp

Residual mother-to-child transmission of HIV in Burkina Faso

Background: Burkina Faso is one of the countries in West Africa most affected by the HIV/AIDS pandemic, despite the implementation of a mother-to-child HIV transmission prevention program as a strategy to reduce the risk of vertical transmission of the disease.Objective: To assess the current risk of mother-to-child transmission of HIV in Burkina Faso.Materials and methods: A prospective study was conducted between December 2014 and July 2016, in the 13 health regions of Burkina Faso. Women who were screened HIV-positive during a prenatal consultation were followed until delivery. Their babies received dry blood spot (DBS) at birth, at week 6 and at 1year, to screen for HIV.Results: Overall, 186 pregnant women were included in the study, with a mean age of 29.17±6.13 years. Of their children, 430 DBS actually received a PCR test, giving a 91.1% PCR implementation rate. After analyses, 6 (1.3%) babies were identified as carriers of HIV1. The newborn’s serological status was associated with delivery pattern (p=0.000), the administration of antiretroviral drugs to the mother after delivery (p=0.0064), the administration of Nevirapine to the newborn at birth (p=0.022), the use of contraceptive methods after delivery (p=0.028) and the presence of breast affections/infections since delivery (p=0.013).Conclusion: The results of our study are encouraging and demonstrate the effectiveness of interventions in the mother-tochild prevention program (PMTCT) for HIV-positive pregnant women can be improved through early initiation of triple therapy in early pregnancy and improved adherence to antiretroviral (ARV) therapy.Keywords: Burkina Faso, HIV/AIDS, mother-to-child transmission, antiretroviral drugs, pregnant wome

The sticky resting box, a new tool for studying resting behaviour of Afrotropical malaria vectors

Background: Monitoring densities of adult mosquito populations is a major challenge in efforts to evaluate the epidemiology of mosquito-borne diseases, and their response to vector control interventions. In the case of malaria, collection of outdoor-resting Anophelines is rarely incorporated into surveillance and control, partially due to the lack of standardized collection tools. Such an approach, however, is increasingly important to investigate possible changes in mosquito behaviour in response to the scale up of Insecticide Treated Nets and Indoor Residual Spraying. In this study we evaluated the Sticky Resting Box (SRB) - i.e. a sticky variant of previously investigated mosquito Resting Box, which allows passive collection of mosquitoes entering the box – and compared its performance against traditional methods for indoor and outdoor resting mosquito sampling.<p></p> Methods: Daily collections were carried out in two neighbouring villages of Burkina Faso during rainy season 2011 and dry season 2012 by SRB located indoors and outdoors, and by Back-Pack aspiration inside houses (BP) and in ad hoc built outdoor pit-shelters (PIT).<p></p> Results: Overall, almost 20,000 Culicidae specimens belonging to 16 species were collected and morphologically identified. Malaria vectors included Anopheles coluzzii (53%), An. arabiensis (12%), An. gambiae s.s. (2.0%) and An. funestus (4.5%). The diversity of species collected in the two villages was similar for SRB and PIT collections outdoors, and significantly higher for SRB than for BP indoors. The population dynamics of An. gambiae s.l. mosquitoes, as obtained by SRB-collections was significantly correlated with those obtained by the traditional methods. The predicted mean estimates of An. gambiae s.l. specimens/sampling-unit/night-of-collections was 6- and 5-times lower for SRB than for BP indoors and PIT outdoors, respectively.<p></p> Conclusions: Overall, the daily performance of SRB in terms of number of malaria vectors/trap was lower than that of traditionally used approaches for in- and outdoor collections. However, unlike these methods, SRB could be set up to collect mosquitoes passively over at least a week. This makes SRB a promising tool for passively monitoring anopheline resting populations, with data presented here providing guidance for how to set up SRB-based collections to acquire information comparable to those obtained with other methods.<p></p&gt

OFDM codée pour le haut débit en fibre optique avec les codes correcteurs convolutifs, BCH, RS et LDPC

Ce document présente une comparaison des performances des modulations OFDM (Orthogonal Frequency Division Multiplexing) codées pour la transmission optique haut débit à l’aide des techniques de codage canal convolutif, BCH, LDPC et Reed Solomon. L’évaluation des performances se base d’une part sur l’EVM (Error Vector Magnitude) afin d’apprécier les effets des imperfections du canal optique; et d’autre part sur l’estimation du taux d’erreur binaire (BER) en fonction de l’OSNR. Les simulations sont réalisées au débit de 10Gbit/s sur 1000 Km dans un environnement de cosimulation avec les logiciels VPITransmissionMaker et Matlab. Les résultats ont révélé que ces codes correcteurs d’erreurs et en particulier les codes LDPC sont bien efficaces et adaptées au haut débit, ils constituent des solutions satisfaisantes pour le COFDM dans la réduction des effets de la dispersion chromatique, de la PMD, des interférences entre symboles (ISI) et des non linéarités.Mots-clés : OFDM, haut débit, BER, fibre optique, codes correcteurs d’erreur.Coded OFDM for high-speed transmission in optical fiber with convolutional, BCH, RS and LDPC codes This paper presents a comparison of the performances of coded OFDM (Orthogonal Frequency Division Multiplexing) for optical broadband transmission using convolutional, BCH, Reed Solomon and LDPC channel coding techniques. The performance evaluation is based firstly on the EVM (Error Vector Magnitude) to assess the effects of imperfections in the channel, and secondly on the estimated bit error rate (BER) based on OSNR. The simulations are performed at a rate of 10Gb/s over 1000 km in a cosimulation environment using VPITransmissionMaker and Matlab software. The results showed that the error correcting codes and particularly LDPC codes are well suited and efficient for broadband, they provide satisfactory solutions for COFDM in reducing the effects of chromatic dispersion, PMD, Inter-symbol interference (ISI) and nonlinearities.Keywords : OFDM, broadband, BER, optical fiber, error correcting codes

Effects of environmental, living space and climate variability on the utilization of impregnated bed nets in west Cameroon: A community based survey for policy implementation

Background: Despite the fact that Long Lasting Impregnated Mosquito Net (LLIN) represents one of the most effective tools in fighting malaria, its use remains limited. Our study aimed at determining how environmental, household characteristics and climate affect bed net use. Methodology: A cross sectional descriptive and analytic study was carried out from January to April 2014 in Mifi health district. Data collected were collected in households during a face to face interview with standard household questionnaires, entered and analyzed using Epi Info software version 3.5.3. Graphics and tables were obtained using MS Excel and Word. Results: Of the 317 participants interviewed, average age was 33.23 years (SD = 10.80) and female sex predominant (85.2%). Most participants had attended secondary education 53.6% (n= 170), married marital status was most represented (58.1%; n= 185).75.4% (n=239) of households had at least 1 LLIN and average district coverage estimated to 1 LLIN for 3.3 persons. 78% of occupants in households with at least one LLIN had slept under the night before the survey. The presence of a ceiling in a house reduced net usage by 2.5% (p = 0.67) compared to house lacking ceiling. Standing waters around the compound increased net utilization rate to 16.6% (p = 0.03), whereas the presence of a covered well decreased the rate by 1.4% (p = 0.86). The dry season was identified as the period during which 86.8% (n= 239) of respondents sleep less under a net. Heat (57.60% n = 138/239), increased choking (2.5%), reduction in vector breeding sites (39.90%; n = 95) were cited as main reasons. Conclusion: Although classified as zone of continuous transmission, our findings indicate that bed net usage by our study population depends on environmental, household characteristics and climate. There is therefore an urgent need to develop strategic communication and sensitization campaigns coupled to environmental management to help scale up and optimize malaria burden reductio

Prevalence of HIV, HBV and Chlamydia infections in Cameroonian University context: case of the University of Dschang, in the Western Region

Introduction: In sub-Saharan Africa HIV infection remains largely epidemic, whereas HBV infection is highly endemic (>8%). In Cameroon, HIV prevalence is 4.3%. Concerning HBV and chlamydia infections, their prevalence are both ≥10%. Young adults, including university students, are the population groups mostly affected. Epidemiological data on these infections, among university students could be helpful to implement specific prevention strategies. Methods: A descriptive study was performed in May 2013 among 624 students from the University of Dschang, Cameroon. Participants were screened for HIV, HBV and Chlamydia infections. Data was collected by a standard questionnaire and analyzed by Epi Info. Results: Average age of participants was 23.3 years (σ = 3.2) with female predominance (58.7%). Prevalence of HIV, HBV and Chlamydia infection was 1.1% (7/624), 2.8% (5/176) and 2.0% (2/100) respectively. 83.2% of participants were sexually active. Concerning sexual risk behaviors, participants reported having multi partners (14.8%), using condom occasionally (58.6%) or never (5.0%). 100%, 62.6% and 52.2% reported to be aware on HIV, HBV and Chlamydia infections respectively. In addition, only 5.5% and 21.3% of the participants were aware of their HBV and Chlamydia status respectively, versus 64.4% for HIV. The excessive cost of HBV and Chlamydia tests has been identified as the major barrier to testing (87.6%). Conclusion: Among college Cameroonian students the prevalence of HIV, HBV and Chlamydia infections seems to be relatively low if compared to general population. However, having multiple sexual partners in addition to non-systematic use of condoms during sexual intercourse represents risk behaviors among students. Awareness campaigns and screening facilitation on HBV and chlamydia infections need to be strengthened

Résultats fonctionnels de la chirurgie de la cataracte par phacoalternative avec implantation en chambre postérieure: à propos de 300 cas à Bobo Dioulasso (Burkina Faso)

La cataracte est la première cause de cécité curable dans le monde. Son traitement est chirurgical. Le but de notre travail a été d'évaluer les résultats de la phacoalternative ou la chirurgie de la cataracte à petite incision. Il s'est agi d'une étude transversale descriptive à collecte prospective allant du 1er janvier au 31 septembre 2014, chez des patients âgés d'au moins 40 ans. Les données socio-démographiques, l'acuitévisuelle, l'astigmatisme et les complications ont été évalués.Nous avons inclus 300 yeux de 286 patients. L'âge moyen était de 66 ans (écart type9,93) avec une prédominance masculine de 57,7%. Les co-morbidités étaient dominées par l'hypertension artérielle 30,33% des cas. L'acuitévisuelle pré-opératoire était de moins de 1/20è dans 70, 7% des cas. En biométrie, la puissance moyenne était de 21,50 dioptries. L'implant posé aété adéquat dans 60%. Les principales complications per-opératoires  étaient le chémosis post-anesthésie 4,67% et l'issue de vitrée moins de 2% des cas. Les complications post opératoires précoces ont été dominées par l'oedème de cornée 26,33%, et les complications tardives par la cataracte secondaire. L'astigmatisme induit était de 1, 12 dioptrie en  moyenne (écart type 1,26). Sans correction, les résultats visuels étaientmauvais dans moins de 1%, limites dans 31%, et bons 68% suivants les normes de l'Organisation Mondiale de la Santé. La phacoalternative donne des résultats satisfaisants, avec peu de complications. L'amélioration du plateau technique et la disponibilité d'implants adéquats pourraient les améliorer

Epidemiology of Syphilis in regional blood transfusion centres in Burkina Faso, West Africa

Introduction: Syphilis remains a major public health problem in  sub-Saharan Africa, including Burkina Faso. However, few published data are available on the prevalence of syphilis in the population. This study had two main objectives: to determine the seroprevalence of syphilis in acohort of 37,210 first time blood donors and to study socio-demographic factors associated with the risk of infection by Treponema pallidum.Methods: Antibodies to Treponema pallidum were screened by using  Reagin Rapid Test (RPR) and confirmed by treponema pallidum  haemagglutination test (TPHA). Results: The overall seroprevalence of syphilis was 1.5% among first time blood donors and was significantly different between centers (p <0.001). The infection was significantly higher in men than women among blood  donors in Ouagadougou and Fada N´gourma (P = 0.001 and P = 0.034). The overall seroprevalence of syphilis among blood donors was not  associated with either age group or HIV status. In contrast, a significantly high seroprevalence of syphilis was observed in blood donors with HBsAg (P = 0.014) and anti-HCV (P = 0.007) positive.Conclusion: Our report shows a low seroprevalence of syphilis in the  representative sample of the population of Burkina Faso. The  seroprevalence of syphilis remains unequally distributed between urban and rural areas and was not associated with HIV infection

Past, Present and Future Perspectives on Groundnut Breeding in Burkina Faso

Groundnut (Arachis hypogaea L.) is a major food and cash crop in Burkina Faso. Due to the growing demand for raw oilseeds, there is an increasing interest in groundnut production from traditional rain-fed areas to irrigated environments. However, despite implementation of many initiatives in the past to increase groundnut productivity and production, the groundnut industry still struggles to prosper due to the fact of several constraints including minimal development research and fluctuating markets. Yield penalty due to the presence of drought and biotic stresses continue to be a major drawback for groundnut production. This review traces progress in the groundnut breeding that started in Burkina Faso before the country’s political independence in 1960 through to present times. Up to the 1980s, groundnut improvement was led by international research institutions such as IRHO (Institute of Oils and Oleaginous Research) and ICRISAT (International Crops Research Institute for the Semi-Arid Tropics). However, international breeding initiatives were not su�cient to establish a robust domestic groundnut breeding programme. This review also provides essential information about opportunities and challenges for groundnut research in Burkina Faso, emphasising the need for institutional attention to genetic improvement of the crop