L’epilepsie en milieu scolaire : enquete chez les enseignants de la ville de Kati au Mali et revue de la litterature

Introduction La prévalence de l’épilepsie en Afrique subsaharienne est élevée. Nous avons mené une étude transversale et descriptive dans l’ensemble des écoles primaires de la ville de Kati (200 000 habitants). Les enseignants furent interviewés de manière exhaustive à l’aide de questionnaires portant, d’une part, sur les connaissances, attitudes et pratiques des enseignants en matière d’épilepsie et, d’autre part, sur leurs avis sur les conséquences psychologiques, sociales pour l’enfant épileptique et les incidences sur sa scolarité.Résultats Nous avons interrogé 92 enseignants (60 hommes et 32 femmes). L’âge moyen des enseignants était de 30 ans. La majorité d’entre eux avait une expérience professionnelle de plus de 5 ans. Environ 38% des enseignants attribuaient la maladie à une cause surnaturelle. Plus de 39% des enseignants pensaient que l’épilepsie était contagieuse et 61% pensaient que l’épilepsie était incurable. 79% interdisaient systématiquement la pratique du sport à l’enfant épileptique. Environ 55% pensaient que l’enfant épileptique avait des capacités cognitives inférieures à celles de l’enfant non épileptique et 88% affirmaient que l’enfant épileptique était incapable d’avoir une scolarité normale. 59% trouvaient que l’élève épileptique était victime de stigmatisation et de marginalisation. Devant une crise, 68% renvoyaient l’enfant au domicile.Conclusion Ce travail fait apparaître un besoin de formation des enseignants en matière d’épilepsie. Les données actuelles sur la fréquence de l’épilepsie en milieu scolaire justifient une attention particulière des services de santé et de ceux de l’éducation nationale sur la scolarisation de l’enfant épileptique.Mots clés : Epilepsie, Ecole, Enseignants, Mali, Pratiques

Quantitative-genetic parameters of sorghum growth under striga infestation in Mali and Kenya

To estimate quantitative genetic parameters of sorghum for resistance to the hemi-parasitic weed striga (Striga hermonthica) and for agronomic traits, 36 diallel F2 populations including their nine parental lines (cultivars N 13, Framida, 555, IS 9830, Seredo, M35-1, E 36-1, DJ 1195 and IS 1037) and five local cultivars as controls (Wagita, Nakhadabo, CSM 335, CSM 228 and Bengou Local), were evaluated under severe striga infestation at two locations each in Mali (Samanko and Cinzana) and Kenya (Kibos and Alupe). Location means for grain yield ranged from 132 to 254 g/m2. F2 populations outyielded lines on average by 18%. For striga emergence traits, F2 heterosis values ranged from -36% to 232% among populations. Genetic and genotype × environment interaction variances of lines and F2s were highly significant for all traits. Broad sense heritabilities for areas under striga severity progress curves and grain yield were 0.83 and 0.90 in lines, and 0.81 and 0.89 in F2s, respectively. General and specific combining ability, and their interaction effects with locations were significant for most traits. F2 superiority for grain yield under striga infestation demonstrates the potential merit of heterozygous cultivars in the target areas. Significant genotype × environment interaction entails multilocational testing to identify stable resistance. A combination of resistance with striga tolerance is recommended to breeders

Diallel analysis of sooty stripe resistance in sorghum

Sooty stripe [Ramulispora sorghi (Ellis and Everhart) Olive and Lefebre] is a widespread foliar disease of sorghum [Sorghum bicolor (L.) Moench] in West Africa, responsible for grain yield losses up to 46%. We studied the inheritance of sooty stripe resistance in a 9 × 9 sorghum F2-population diallel grown together with parent lines and checks in1996 under natural disease pressure at two locations in Mali. The percentage of infected leaf area was determined twice over a two-week interval during the season. At the second evaluation, the mean sooty stripe severity amounted to 13% infected leaf area at Samanko and 12% at Cinzana. The frequency distribution of the entries was approximately normal for the mean disease severity, averaged across assessment dates and locations, pointing to the involvement of multiple genes. With the data combined across the two locations, genetic differences among lines and among F2 populations were highly significant. Genotype × location interaction variances were also significant but much smaller than the genetic variances. Broad-sense heritability estimates were 0.92 for lines and 0.94 for the F2 populations, for the mean percentage infected leaf area across the two assessment dates. General combining ability effects (GCA) determined most of the differences among the F2 populations. Specific combining ability effects (SCA), and the interactions of GCA or SCA with locations were also significant but less important. Line performance per se was highly correlated with GCA. Because of the high heritability and predominance of additive effects, prospects are good for the genetic improvement of resistance to sooty stripe in sorghum in Mali, using simple pedigree or recurrent selection procedure

Transcriptomic evidence for modulation of host inflammatory responses during febrile Plasmodium falciparum malaria

Identifying molecular predictors and mechanisms of malaria disease is important for understanding how Plasmodium falciparum malaria is controlled. Transcriptomic studies in humans have so far been limited to retrospective analysis of blood samples from clinical cases. In this prospective, proof-of-principle study, we compared whole-blood RNA-seq profiles at pre-and post-infection time points from Malian adults who were either asymptomatic (n = 5) or febrile (n = 3) during their first seasonal PCR-positive P. falciparum infection with those from malaria-naïve Dutch adults after a single controlled human malaria infection (n = 5). Our data show a graded activation of pathways downstream of pro-inflammatory cytokines, with the highest activation in malaria-naïve Dutch individuals and significantly reduced activation in malaria-experienced Malians. Newly febrile and asymptomatic infections in Malians were statistically indistinguishable except for genes activated by pro-inflammatory cytokines. The combined data provide a molecular basis for the development of a pyrogenic threshold as individuals acquire immunity to clinical malaria

Pattern analysis of genotype × environment interaction for striga resistance and grain yield in African sorghum trials

The parasitic weed Striga hermonthica (Del.) Benth. seriously limits sorghum [Sorghum bicolor (L.) Moench] production in Sub-Saharan Africa. As an outbreeder, S. hermonthica is highly variable with an extraordinary capacity to adapt to different hosts and environments, thereby complicating resistance breeding. To study genotype x environment (G x E) interaction for striga resistance and grain yield, nine sorghum lines, 36 F2 populations and five local checks were grown under striga infestation at two locations in both Mali and Kenya. Mean squares due to genotypes and G x E interaction were highly significant for both sorghum grain yield and area under striga severity progress curve(ASVPC, a measure of striga emergence and vigor throughout the season). For grain yield, the entry x location-within-country interaction explained most of the total G x E while for ASVPC, entry x country and entry x location-within-country interactions were equally important. Pattern analysis (classification and ordination techniques) was applied to the environment-standardized matrix of entry x environment means. The classification clearly distinguished Malian from Kenyan locations for ASVPC, but not for grain yield. Performance plots for different entry groups showed differing patterns of adaptation. The ordination biplot underlined the importance of entry x country interaction for ASVPC. The F2 derived from the cross of the striga-resistant line Framida with the striga-tolerant cultivar Seredo was the superior entry for both grain yield and ASVPC, underlining the importance of combining resistance with tolerance in striga resistance breeding. The observed entry x country interaction for ASVPC may be due to the entries' different reactions to climatic conditions and putative differences in striga virulence in Mali and Kenya

Utility of indirect and direct selection traits for improving Striga resistance in two sorghum recombinant inbred populations

Breeding of sorghum (Sorghum bicolor L. Moench) for resistance to the parasitic weed Striga hermonthica (Del.) Benth. has been hampered by the difficulty of evaluating host resistance in the field and lack of reliable screening techniques. Therefore, we investigated the value of various indirect and direct measures of Striga resistance as selection traits. Two sorghum recombinant inbred populations of 226 F3:5 lines each were developed from the crosses (1) IS 9830 × E 36-1 and (2) N 13 × E 36-1. Striga-resistant line IS 9830 is characterized by low stimulation of Striga seed germination, whereas Striga-susceptible line E 36-1 produces germination stimulants in abundance. Line N 13 possesses "mechanical" resistance and probably also an antibiosis mechanism. Resistance was assessed in 1997 and 1998 using in vitro agar-gel assays with Striga seeds from Kenya, Mali, and Niger, pot trials in the respective three countries, and field experiments in Kenya and Mali. The agar-gel assay proved to be a useful, precise and fast indirect selection method to screen for sorghum entries with the low-stimulant character. However, correlation analysis showed that this resistance mechanism was ineffective in some environments, especially in Kenya, pointing to the necessity of field evaluation. Because of low heritability estimates and moderate to low correlations to Striga resistance under field conditions, pot screening appeared to be of limited use in breeding programs. The field trials confirmed the effectiveness of several direct measures of Striga resistance in sorghum: emerged Striga counts, Striga severity index, and area under the Striga number or severity progress curves. A two-row plot field layout with an empty row between plots, coupled with artificial infestation of test rows, lattice design and six replications offered an improved screening procedure that achieved high heritability. Significant genotype × environment interactions in the field experiments stress the importance of multi-locational trials to achieve stable Striga resistance

Is chloroquine chemoprophylaxis still effective to prevent low birth weight? Results of a study in Benin

BACKGROUND: In areas of stable transmission, malaria during pregnancy is associated with severe maternal and foetal outcomes, especially low birth weight (LBW). To prevent these complications, weekly chloroquine (CQ) chemoprophylaxis is now being replaced by intermittent preventive treatment with sulfadoxine-pyrimethamine in West Africa. The prevalence of placental malaria and its burden on LBW were assessed in Benin to evaluate the efficacy of weekly CQ chemoprophylaxis, prior to its replacement by intermittent preventive treatment. METHODS: In two maternity clinics in Ouidah, an observational study was conducted between April 2004 and April 2005. At each delivery, placental blood smears were examined for malaria infection and women were interviewed on their pregnancy history including CQ intake and dosage. CQ was measured in the urine of a sub-sample (n = 166). Multiple logistic and linear regression were used to assess factors associated with LBW and placental malaria. RESULTS: Among 1090 singleton live births, prevalence of placental malaria and LBW were 16% and 17% respectively. After adjustment, there was a non-significant association between placental malaria and LBW (adjusted OR = 1.43; P = 0.10). Multiple linear regression showed a positive association between placental malaria and decreased birth weight in primigravidae. More than 98% of the women reported regular chemoprophylaxis and CQ was detectable in 99% of urine samples. Protection from LBW was high in women reporting regular CQ prophylaxis, with a strong duration-effect relationship (test for linear trend: P < 0,001). CONCLUSION: Despite high parasite resistance and limited effect on placental malaria, a CQ chemoprophylaxis taken at adequate doses showed to be still effective in reducing LBW in Benin

Intermittent preventive treatment with sulphadoxine-pyrimethamine is effective in preventing maternal and placental malaria in Ibadan, south-western Nigeria

<p>Abstract</p> <p>Background</p> <p>Intermittent preventive treatment with sulphadoxine-pyrimethamine (IPT-SP) is currently the recommended regimen for prevention of malaria in pregnancy in endemic areas. This study sets out to evaluate the effectiveness of IPT-SP in the prevention of maternal and placental malaria in parturient mothers in Ibadan, Nigeria, where the risk of malaria is present all year round.</p> <p>Method</p> <p>During a larger study evaluating the epidemiology of congenital malaria, the effect of malaria prophylaxis was examined in 983 parturient mothers. Five hundred and ninety eight mothers (60.8%) received IPT-SP, 214 (21.8%) received pyrimethamine (PYR) and 171 (17.4%) did not take any chemoprophylactic agent (NC).</p> <p>Results</p> <p>The prevalence of maternal parasitaemia in the IPT-SP, PYR and NC groups was 10.4%, 15.9% and 17% respectively (p = 0.021). The prevalence of placental parasitaemia was 10.5% in the IPT-SP, 16.8% PYR and 17% NC groups, respectively (p = 0.015). The prevalence of maternal anaemia (haematocrit <30%) was 5.7% vs. 8.9% vs. 13.4% among the IPT-SP, PYR and NC groups respectively (p < 0.0001) while that of pre-term delivery (GA <37 weeks) was 10.5%, 19.2% and 25.3% among IPT-SP, PYR and NC groups respectively (p < 0.0001). Babies born to mothers in the IPT-SP, PYR and NC groups had mean birth weights of 3204 ± 487.16, 3075 ± 513.24 and 3074 ± 505.92 respectively (ρ < 0.0001). There was a trend towards a lower proportion of low birth weight babies in the IPT-SP group (p = 0.095).</p> <p>Conclusion</p> <p>IPT-SP is effective in preventing maternal and placental malaria as well as improving pregnancy outcomes among parturient women in Ibadan, Nigeria. The implementation of the recently adopted IPT-SP strategy should be pursued with vigour as it holds great promise for reducing the burden of malaria in pregnancy in Nigeria.</p