Maman Laminou Ibrahim
CERMES

Biotechnology

MVD. MSc. PhD.
21.40

Publications

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    Dataset: supp AL2
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    Dataset: supp AL
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    Maman Laminou Ibrahim
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    ABSTRACT: Justification: Malaria remains a major public health problem in the tropical countries. The socio-economic situation of malaria-endemic countries coupled with the development of resistance strains of Plasmodium falciparum to commonly used molecules requires the development of new antimalarial drugs. Objective: The antiplasmodial activity of ethanol extracts of six plants of the traditional medicine of Niger was evaluated and compared with that of Artemisia annua. Methodology and results: the MarkIII test of WHO with W2 chloroquin-resistant strain of Plasmodium falciparum was used. The antiplasmodial activity was discussed in light of the phytochemical profile of different plants, chemical screening determined by standard methods. Ximenia Americana and Prosopis africana’s extracts have excellent antiplasmodial activity, with respectively IC50 of 0.05 and 0.5Cg/ml. These activities are better than Artemisia annua activity (IC50 = 0.74Cg/ml) used as reference. However, a moderate activity was found for Chrozophora brocchiana (8.2Cg/ml), a weak activity for Polycarpaea eriantha and Detarium microcarpum (18.4Cg/ml and 31Cg/ml), and no activity for Saba senegalensis’s extract. Conclusion and application of results: This study justifies traditional uses of Ximenia americana and Prosopis africana against malaria. A bioguided fractionation of these extracts would identify molecules responsible for their antiplasmodial activity. Moreover, these results could lead to the design of improved traditional medicines in the basis of these plants. Chrozophora brocchiana, Polycarpaea eriantha and Detarium microcarpum’s extracts were less active than the reference. Saba senegalensis had no antiplasmodial activity.
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    Maman Laminou Ibrahim
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    DESCRIPTION: Le paludisme est un problème majeur de santé publique au Niger. Le Fonds Mondial de la lutte contre le sida, la tuberculose et le paludisme a lancé en 2011 une initiative appelée « Affordable Medecines Facility - Malaria» ou AMFm qui vise à rendre les combinaisons thérapeutiques à base d’artémisinine (CTA) plus disponibles, plus accessibles et de lutter contre la résistance à l’artémisinine. C’est dans ce contexte que nous avons mené une étude comparative, randomisée, à deux bras ouverts de l’efficacité thérapeutique des associations artémether-luméfantrine (AL) et artésunate-amodiaquine (AM) au niveau du site sentinelle de Gaya. L’objectif de l’étude est d’évaluer puis de comparer l’efficacité et la tolérance de ces deux CTA. La méthode utilisée est le protocole OMS/2003 avec le suivi de 28 jours. 370 patients fébriles ont été examinés. 159 patients ont été inclus dont 79 (49.4%) pour le bras AL et 80 (50.3%) pour le bras AM. La réponse clinique et parasitologique adéquate est respectivement de 94.8% pour AL et 97.1% AM. Il n’y a pas de différence statistiquement significative d’efficacité entre les deux molécules (P=0.4). Il n’y a pas aussi de différence statistiquement significative d’effet secondaire entre les deux molécules (P=0.18). AL et AM sont d’efficacité et de tolérance comparables. Mots clés : Résistance, P.falciparum, Artémether luméfantrine, Artésunate amodiaquine et Niger.
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    ABSTRACT: Background Artemether–lumefantrine is the most widely used artemisinin-based combination therapy for malaria, although treatment failures occur in some regions. We investigated the effect of dosing strategy on efficacy in a pooled analysis from trials done in a wide range of malaria-endemic settings. Methods We searched PubMed for clinical trials that enrolled and treated patients with artemether–lumefantrine and were published from 1960 to December, 2012. We merged individual patient data from these trials by use of standardised methods. The primary endpoint was the PCR-adjusted risk of Plasmodium falciparum recrudescence by day 28. Secondary endpoints consisted of the PCR-adjusted risk of P falciparum recurrence by day 42, PCR-unadjusted risk of P falciparum recurrence by day 42, early parasite clearance, and gametocyte carriage. Risk factors for PCR-adjusted recrudescence were identified using Cox's regression model with frailty shared across the study sites. Findings We included 61 studies done between January, 1998, and December, 2012, and included 14 327 patients in our analyses. The PCR-adjusted therapeutic efficacy was 97·6% (95% CI 97·4–97·9) at day 28 and 96·0% (95·6–96·5) at day 42. After controlling for age and parasitaemia, patients prescribed a higher dose of artemether had a lower risk of having parasitaemia on day 1 (adjusted odds ratio [OR] 0·92, 95% CI 0·86–0·99 for every 1 mg/kg increase in daily artemether dose; p=0·024), but not on day 2 (p=0·69) or day 3 (0·087). In Asia, children weighing 10–15 kg who received a total lumefantrine dose less than 60 mg/kg had the lowest PCR-adjusted efficacy (91·7%, 95% CI 86·5–96·9). In Africa, the risk of treatment failure was greatest in malnourished children aged 1–3 years (PCR-adjusted efficacy 94·3%, 95% CI 92·3–96·3). A higher artemether dose was associated with a lower gametocyte presence within 14 days of treatment (adjusted OR 0·92, 95% CI 0·85–0·99; p=0·037 for every 1 mg/kg increase in total artemether dose). Interpretation The recommended dose of artemether–lumefantrine provides reliable efficacy in most patients with uncomplicated malaria. However, therapeutic efficacy was lowest in young children from Asia and young underweight children from Africa; a higher dose regimen should be assessed in these groups.
    The Lancet Infectious Diseases 03/2015; 15(6):692-702. · 19.45 Impact Factor
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    Maman Laminou Ibrahim
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    ABSTRACT: Background Artesunate-amodiaquine (AS-AQ) is one of the most widely used artemisinin-based combination therapies (ACTs) to treat uncomplicated Plasmodium falciparum malaria in Africa. We investigated the impact of different dosing strategies on the efficacy of this combination for the treatment of falciparum malaria. Methods Individual patient data from AS-AQ clinical trials were pooled using Worldwide Antimalarial Resistance Network (WWARN) standardised methodology. Risk factors for treatment failure were identified using a Cox regression model with shared frailty across study sites. Results Forty-three studies representing 9,106 treatments from 1999-2012 were included in the analysis; 4,138 (45.4%) treatments were with a fixed dose combination with an AQ target dose of 30 mg/kg (FDC), 1,293 (14.2%) with a non-fixed dose combination with an AQ target dose of 25 mg/kg (loose NFDC-25), 2,418 (26.6%) with a non-fixed dose combination with an AQ target dose of 30 mg/kg (loose NFDC-30), and the remaining 1,257 (13.8%) with a co-blistered non-fixed dose combination with an AQ target dose of 30 mg/kg (co-blistered NFDC). The median dose of AQ administered was 32.1 mg/kg [IQR: 25.9-38.2], the highest dose being administered to patients treated with co-blistered NFDC (median = 35.3 mg/kg [IQR: 30.6-43.7]) and the lowest to those treated with loose NFDC-25 (median = 25.0 mg/kg [IQR: 22.7-25.0]). Patients treated with FDC received a median dose of 32.4 mg/kg [IQR: 27- 39.0]. After adjusting for reinfections, the corrected antimalarial efficacy on day 28 after treatment was similar for co-blistered NFDC (97.9% [95% confidence interval (CI): 97.0- 98.8%]) and FDC (98.1% [95% CI: 97.6%-98.5%]; P = 0.799), but significantly lower for the loose NFDC-25 (93.4% [95% CI: 91.9%-94.9%]), and loose NFDC-30 (95.0% [95% CI: 94.1%-95.9%]) (P < 0.001 for all comparisons). After controlling for age, AQ dose, baseline parasitemia and region; treatment with loose NFDC-25 was associated with a 3.5-fold greater risk of recrudescence by day 28 (adjusted hazard ratio, AHR = 3.51 [95% CI: 2.02-6.12], P < 0.001) compared to FDC, and treatment with loose NFDC-30 was associated with a higher risk of recrudescence at only three sites.
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    ABSTRACT: Le paludisme est un problème majeur de santé publique dans la zone intertropicale. Les souches de Plasmodium falciparum deviennent aussi de plus en plus résistantes aux molécules couramment utilisées et même contre l’artémisinine. Il devient urgent de trouver de nouvelles molécules antipaludiques. Nous avons évalué puis comparé l’activité antiplasmodiale des extraits éthanoliques dégraissés de quatre plantes issues de la médicine traditionnelle du Niger à celle d’Artemisia annua sur la souche de Plasmodium falciparum chloroquinorésistante W2. La méthode utilisée est celle de l’OMS/2001 ou test de Mark III. L’activité antiplasmodiale a été discutée à la lumière du profil phytochimique des différentes plantes, déterminé par les méthodes standards de screening chimique. Cassia nigricans, Sebastiania chamaelea et Euphorbia hirta présentent une bonne activité antiplasmodiale. Leurs IC50 respectives sont de 2,8μg/ml, 3,3μg/ml et 3,7μg/ml. Cela justifie leur utilisation contre le paludisme en pharmacopée traditionnelle du Niger. Par contre, Cassia occidentalis présente une activité modérée avec une IC50 de 10,4μg/ml.
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    Maman Laminou Ibrahim
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    ABSTRACT: L’édition 2014 du Cours National de Paludologie (CNP) s’est tenue du 17 au 28 Novembre 2013 au Centre de Formation Pierre et Anne-Marie Moussa. Cette formation est organisée par le CERMES en collaboration avec le Programme National de Lutte contre le Paludisme, la Faculté des Sciences de la Santé (FSS) et l’Hôpital National de Niamey. L’objectif général du CNP est de renforcer l’expertise des scientifiques et des agents de santé dans tous les aspects de la paludologie pour la mise à l’échelle des interventions de lutte contre le paludisme et une initiation à la recherche scientifique. Le CNP a comme objectifs spécifiques:  Connaitre les stratégies et les outils pour lutter contre le paludisme:  Savoir faire face à une épidémie palustre ou une situation d’urgence,  Maitriser les techniques d’information, d’éducation et de communication pour un changement de comportement (IEC/CCC),  Développer des aptitudes à rédiger un plan stratégique  S’initier à la recherche scientifique.
    Note d'information, Bulletin d'information du CERMES; 02/2015
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    ABSTRACT: Chloroquine (CQ) resistance is widespread in Africa, but few data are available for Niger. Pfcrt haplotypes (aa 56–118) and ex vivo responses to CQ and amodiaquine were characterized for 26 isolates collected in South Niger from children under 15 years of age suffering from uncomplicated falciparum malaria, six years after the introduction of artemisinin-based combinations and the withdrawal of CQ. The wild-type Pfcrt haplotype CVMNK was found in 22 of the 26 isolates, with CVIET sequences observed in only three of the samples. We also describe for the first time a new CVINT haplotype. The ex vivo responses were better for CVMNK than for CVIET parasites. Pfcrt sequence data were compared with those obtained for 26 additional parasitized blood samples collected in Gabon, from an area of CQ resistance used as a control. Our findings suggest that there has been a significant decline in CQ-resistant genotypes since the previous estimates for Niger were obtained. No such decline in molecular resistance to CQ was observed in the subset of samples collected in similar conditions from Gabon.These results have important implications for public health and support the policy implemented in Niger since 2005, which aims to increase the efficacy and availability of antimalarial drugs whilst controlling the spread of resistance.
    Malaria Research and Treatment 11/2014; 2014:7. DOI:10.1155/2014/614190
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    ABSTRACT: Few data are available about malaria epidemiological situation in Niger. However, implementation of new strategies such as vaccination or seasonal treatment of a target population requires the knowledge of baseline epidemiological features of malaria. A population-based study was conducted to provide better characterization of malaria seasonal variations and population groups the most at risk in this particular area. From July 2007 to December 2009, presumptive cases of malaria among a study population living in a typical Sahelian village of Niger were recorded, and confirmed by microscopic examination. In parallel, asymptomatic carriers were actively detected at the end of each dry season in 2007, 2008 and 2009. Among the 965 presumptive malaria cases recorded, 29% were confirmed by microscopic examination. The incidence of malaria was found to decrease significantly with age (p < 0.01). The mean annual incidence was 0.254. The results show that the risk of malaria was higher in children under ten years (p < 0.0001). The number of malaria episodes generally followed the temporal pattern of changes in precipitation levels, with a peak of transmission in August and September. One-thousand and ninety subjects were submitted to an active detection of asymptomatic carriage of whom 16% tested positive; asymptomatic carriage decreased with increasing age. A higher prevalence of gametocyte carriage among asymptomatic population was recorded in children aged two to ten years, though it did not reach significance. In Southern Niger, malaria transmission mostly occurs from July to October. Children aged two to ten years are the most at risk of malaria, and may also represent the main reservoir for gametocytes. Strategies such as intermittent preventive treatment in children (IPTc) could be of interest in this area, where malaria transmission is highly seasonal. Based on these preliminary data, a pilot study could be implemented in Zindarou using IPTc targeting children aged two to ten years, during the three months of malaria transmission, together with an accurate monitoring of drug resistance.
    Malaria Journal 10/2013; 12(1):379. DOI:10.1186/1475-2875-12-379 · 3.49 Impact Factor
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    ABSTRACT: Individuals continuously exposed to malaria gradually acquire immunity that protects from severe disease and high levels of parasitization. Acquired immunity has been incorporated into numerous models of malaria transmission of varying levels of complexity (e.g. Bull World Health Organ 50:347, 1974; Am J Trop Med Hyg 75:19, 2006; Math Biosci 90:385--396, 1988). Most such models require prescribing inputs of mosquito biting rates or other entomological or epidemiological information. Here, we present a model with a novel structure that uses environmental controls of mosquito population dynamics to simulate the mosquito biting rates, malaria prevalence as well as variability in protective immunity of the population. A simple model of acquired immunity to malaria is presented and tested within the framework of the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS), a coupled hydrology and agent-based entomology model. The combined model uses environmental data including rainfall, temperature, and topography to simulate malaria prevalence and level of acquired immunity in the human population. The model is used to demonstrate the effect of acquired immunity on malaria prevalence in two Niger villages that are hydrologically and entomologically very different. Simulations are conducted for the year 2006 and compared to malaria prevalence observations collected from the two villages. Blood smear samples from children show no clear difference in malaria prevalence between the two villages despite pronounced differences in observed mosquito abundance. The similarity in prevalence is attributed to the moderating effect of acquired immunity, which depends on prior exposure to the parasite through infectious bites - and thus the hydrologically determined mosquito abundance. Modelling the level of acquired immunity can affect village vulnerability to climatic anomalies. The model presented has a novel structure constituting a mechanistic link between spatial and temporal environmental variability and village-scale malaria transmission. Incorporating acquired immunity into the model has allowed simulation of prevalence in the two villages, and isolation of the effects of acquired immunity in dampening the difference in prevalence between the two villages. Without these effects, the difference in prevalence between the two villages would have been significantly larger in response to the large differences in mosquito populations and the associated biting rates.
    Parasites & Vectors 08/2013; 6(1):226. DOI:10.1186/1756-3305-6-226 · 3.25 Impact Factor
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    M.L. Ibrahim · B.M.Halima · A. Salissou · S. Boureima · H. Maimouna · M. Abani
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    ABSTRACT: Le Niger a adopté une nouvelle politique thérapeutique du paludisme en 2005. Elle recommande l’artémether luméfantrine (AL) en traitement du paludisme simple, la sulfadoxine pyriméthamine (SP) en traitement préventif intermittent et le retrait de la chloroquine (CQ). Pourtant, la chloroquine continue d’être prescrite et la sulfadoxine pyriméthamine est fréquemment utilisée pour traiter les enfants. Une étude comparative, randomisée, à trois bras aveugles de l’efficacité de l’artémether luméfantrine, la sulfadoxine pyriméthamine et la chloroquine est réalisée à Gaya. L’objectif de l’étude est d’évaluer l’efficacité des trois médicaments. Cette étude a porté sur 208 enfants. Le protocole OMS/2003 est utilisé. Les familles alléliques RO33 et MAD20 du marqueur msp1 puis 3D7 et FC27 du marqueur msp2 sont utilisées pour distinguer réinfestations et recrudescences. 93.6% des patients traités à l’artémether luméfantrine ont une réponse clinique et parasitologique adéquate contre 82.8% des patients traités à la sulfadoxine pyriméthamine et 72% des patients traités à la chloroquine. La différence d’efficacité est statistiquement significative (p=0.04). Au vue de ces résultats, il serait judicieux de retirer la chloroquine. La sulfadoxine pyriméthamine doit être réservée exclusivement aux femmes enceintes. L’artémether luméfantrine doit être prescrit en traitement de première intention.
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    Maman Laminou Ibrahim
    Malaria Journal 01/2013; · 3.49 Impact Factor
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    ABSTRACT: The health authorities of Niger have implemented several malaria prevention and control programmes in recent years. These interventions broadly follow WHO guidelines and international recommendations and are based on interventions that have proved successful in other parts of Africa. Most performance indicators are satisfactory but, paradoxically, despite the mobilization of considerable human and financial resources, the malaria-fighting programme in Niger seems to have stalled, as it has not yet yielded the expected significant decrease in malaria burden. Indeed, the number of malaria cases reported by the National Health Information System has actually increased by a factor of five over the last decade, from about 600,000 in 2000 to about 3,000,000 in 2010. One of the weaknesses of the national reporting system is that the recording of malaria cases is still based on a presumptive diagnosis approach, which overestimates malaria incidence. An extensive nationwide survey was carried out to determine by microscopy and RDT testing, the proportion of febrile patients consulting at health facilities for suspected malaria actually suffering from the disease, as a means of assessing the magnitude of this problem and obtaining a better estimate of malaria morbidity in Niger. In total, 12,576 febrile patients were included in this study; 57% of the slides analysed were positive for the malaria parasite during the rainy season, when transmission rates are high, and 9% of the slides analysed were positive during the dry season, when transmission rates are lower. The replacement of microscopy methods by rapid diagnostic tests resulted in an even lower rate of confirmation, with only 42% of cases testing positive during the rainy season, and 4% during the dry season. Fever alone has a low predictive value, with a low specificity and sensitivity. These data highlight the absolute necessity of confirming all reported malaria cases by biological diagnosis methods, to increase the accuracy of the malaria indicators used in monitoring and evaluation processes and to improve patient care in the more remote areas of Niger. This country extends over a large range of latitudes, resulting in the existence of three major bioclimatic zones determining vector distribution and endemicity. This survey showed that the number of cases of presumed malaria reported in health centres in Niger is largely overestimated. The results highlight inadequacies in the description of the malaria situation and disease risk in Niger, due to the over-diagnosis of malaria in patients with simple febrile illness. They point out the necessity of confirming all cases of suspected malaria by biological diagnosis methods and the need to take geographic constraints into account more effectively, to improve malaria control and to adapt the choice of diagnostic method to the epidemiological situation in the area concerned. Case confirmation will thus also require a change in behaviour, through the training of healthcare staff, the introduction of quality control, greater supervision of the integrated health centres, the implementation of good clinical practice and a general optimization of the use of available diagnostic methods.
    Malaria Journal 03/2012; 11(1):89. DOI:10.1186/1475-2875-11-89 · 3.49 Impact Factor
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    Salissou A · Halima B.M · Abani M · Eric A · Daou M · Boureima S · Maimouna H · Ibrahim M.L
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    ABSTRACT: Background: Malaria, with its width, its gravity and its economic and social consequences remains a major public health problem in tropical countries like Niger. These consequences come to be added the simultaneous or cross résistance of P.falciparum to currents drugs. The National Malaria Programme of Niger adopted artemether-lumefantrine (COARTEM®) in treatment of uncomplicated malaria in 2005. We evaluated the efficacy and safety of artémether-luméfantrine in the treatment of children less than 5 years at Gaya, Tessaoua and Agades, three sentinels’ sites of Niger. Objectives: The main objective of the study is to evaluate the efficacy and the safety of COARTEM® in the treatment of uncomplicated P.falciparum malaria in Niger. Methodology: It is a multicentric, prospective, descriptive and open study with only one arm to evaluate the efficacy and safety of artemether-lumefantrine in children less than 5 years suffering from uncomplicated malaria in Niger. OMS/2003 protocol was used. Results: 389 children were consulted and 199 children were followed for 28 days. 81 children are from Gaya, 70 from Tessaoua and 48 from Agades. After PCR, the clinical and parasitological adequate response (CPAR) of children less than 5 years is 92%. The CPAR is 96.3% at Tessaoua, 94,1% at Agades and 89.6% at Gaya. The difference of response between the three sentinels sites is not significant (p>0 05). Before PCR, the clinical and parasitological adequate response was 88.8%. The COARTEM® is well tolerated. No undesirable effect was observed during the study. Conclusion: COARTEM® is an effective drug, which reduces significantly parasitic and clinical symptoms of malaria. It can be prescribed in treatment of uncomplicated malaria as public health ministry of Niger recommends. COARTEM® is also safety and well tolerated by the patients.

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