355 research outputs found
Un test de rémanence pour l'évaluation des moustiquaires imprégnées basé sur la vitesse du knock-down
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 BOSONÂź 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 polymĂ©rase chain rĂ©action (PCR) nâest pas utilisĂ©e lors de la qualification biologique des dons et cela constitue un facteur de risque de transmission de lâInfection Occulte du virus B (VHB) lors des transfusions sanguines. Lâobjectif de cette Ă©tude Ă©tait de dĂ©terminer la prĂ©valence de lâinfection occulte B chez les donneurs de sang en vue dâune meilleure sĂ©curitĂ© transfusionnelle.
MĂ©thodologie: Une Ă©tude transversale prospective, rĂ©alisĂ©e dâavril Ă octobre 2020 dans la ville de Ouagadougou incluant 300 donneurs de sang AgHBs nĂ©gatif. Lâanticorps anti HBc a Ă©tĂ© dĂ©terminĂ© par les tests rapides de marque BOSONÂź. LâADN du VHB a Ă©tĂ© recherchĂ© chez 75 donneurs par PCR en temps rĂ©el (rt PCR) avec le 7500 Fast Real Time PCR.
RĂ©sultats: Parmi les 300 donneurs AgHBs nĂ©gatifs, 208 (69,3%) Ă©taient des hommes et 92 (30,7%) des femmes. LâĂąge moyen Ă©tait de 30,18 ans. La recherche de lâAc anti-HBc Ă©tait positive dans 39 cas (13 %). Parmi les 75 Ă©chantillons passĂ©s Ă la rt PCR, 3 (4%) Ă©taient positifs pour lâADN du VHB. Sur les 3 cas dâADN VHB positifs, 2 (66,67%) Ă©taient positifs Ac anti HBc et 1 (33,33%) Ac anti HBc nĂ©gatif.
Conclusion: Compte tenu de la prĂ©valence de lâinfection occulte B et ses consĂ©quences chez les donneurs de sang et chez les receveurs, il devient nĂ©cessaire de rechercher, en plus des marqueurs sĂ©rologiques classiques de lâhĂ©patite B, lâADN VHB pour une meilleure sĂ©curitĂ© transfusionnelle.
Mots clĂ©s: PrĂ©valence, Infection occulte de lâHBV, Donneurs de sang, Ouagadougou
 
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 newbornâs 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 â 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>
OFDM codée pour le haut débit en fibre optique avec les codes correcteurs convolutifs, BCH, RS et LDPC
Ce document prĂ©sente une comparaison des performances des modulations OFDM (Orthogonal Frequency Division Multiplexing) codĂ©es pour la transmission optique haut dĂ©bit Ă lâaide des techniques de codage canal convolutif, BCH, LDPC et Reed Solomon. LâĂ©valuation des performances se base dâune part sur lâEVM (Error Vector Magnitude) afin dâapprĂ©cier les effets des imperfections du canal optique; et dâautre part sur lâestimation du taux dâerreur binaire (BER) en fonction de lâOSNR. Les simulations sont rĂ©alisĂ©es au dĂ©bit de 10Gbit/s sur 1000 Km dans un environnement de cosimulation avec les logiciels VPITransmissionMaker et Matlab. Les rĂ©sultats ont rĂ©vĂ©lĂ© que ces codes correcteurs dâerreurs et en particulier les codes LDPC sont bien efficaces et adaptĂ©es au haut dĂ©bit, ils constituent des solutions satisfaisantes pour le COFDM dans la rĂ©duction des effets de la dispersion chromatique, de la PMD, des interfĂ©rences entre symboles (ISI) et des non linĂ©aritĂ©s.Mots-clĂ©s : OFDM, haut dĂ©bit, BER, fibre optique, codes correcteurs dâerreur.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 â„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 (Ï = 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 premiÚre 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 ùgés 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'ùge 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 1/20Ú 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'oedÚme 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 NŽgourma (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 countryâs 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 suïżœcient 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
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