La peche continentale au lac de Songori (region du Gontougo; Nord-Est de la Cote D'Ivoire): Facteurs de production et niveau d'exploitation halieutique

RESUMEL’étude de l’activité de pêche au lac de Songori (environ 1,5 km²) dans la région du Gontougo (Nord- Est de la Côte d’Ivoire) s’est déroulée de janvier 2013 à décembre 2014. Elle montre que la pêche est essentiellement pratiquée par des ivoiriens (100 %) avec une absence de pêcheurs professionnels. Ces acteurs sont majoritairement des pêcheurs-agriculteurs (80 %) et considèrent la pêche comme une activité secondaire. Ils utilisent généralement les filets maillants (89,66 %) comme engins de pêche. Des pirogues monoxyles (83,33 %) constituent les embarcations les plus couramment utilisées. L’effort de pêche est autour de 2,7 pêcheurs/km². Les captures comprennent des espèces économiquement importantes avec une prédominance de Oreochromis niloticus (68,10 % à 78,89 % de la biomasse annuelle). La production annuelle est comprise entre 13,33 et 13,51 t soit entre 88,9 et 90,1 kg/ha/an. Elle reste inférieure aux captures potentielles (entre 100 et 750 kg/ha/an) indiquées par la FAO pour ces plans d’eau ; ce qui montre qu’il peut exister une marge pour augmenter la biomasse exploitée. Toutefois, le manque de professionnalisme des pêcheurs, la vétusté des engins de pêche et l’occupation du tiers (environ) du volume d’eau exploitable par des plantes aquatiques constituent une entrave majeure au développement de cette activité. ABSTRACTINLAND FISHING AT LAKE SONGORI (GONTOUGO REGION; NORTH-EAST OF THE IVORY COAST): FACTORS OF PRODUCTION AND LEVEL OF FISHING EXPLOITATIONThe study of fishing activity on Lake Songori (about 1.5 km²) in the area of Gontougo (north-east of Ivory Coast) took place from January 2013 to December 2014. It shows that fishing is mainly practiced by Ivorians (100%) with no professional fishermen. These actors are mainly fishermen-farmers (91.67%) and consider fishing as a secondary activity. They generally use gillnets (89.66%) as fishing gear. Monoxyls canoes (83.33%) are the most commonly used boats. The fishing effort is around 2.7 fishermen / km². Catches include economically important species with a predominance of Oreochromis niloticus (68.10% to 78.89% of the annual biomass). The annual production is between 13,33 and 13,51 t or between 88.9 and 90.1 kg / ha / year. It remains lower the potential catches (between 100 and 750 kg / ha / year) reported by FAO for these water bodies; which shows that there may be a margin to increase the exploited biomass. However, the lack of professionalism of fishermen, the obsolescence of fishing gear and the occupation of about one-third of the volume of water exploitable by aquatic plants constitute a major obstacle to the development of this activity

Spatial mapping and prediction of Plasmodium falciparum infection risk among school-aged children in Côte d'Ivoire

BACKGROUND: In Côte d'Ivoire, malaria remains a major public health issue, and thus a priority to be tackled. The aim of this study was to identify spatially explicit indicators of Plasmodium falciparum infection among school-aged children and to undertake a model-based spatial prediction of P. falciparum infection risk using environmental predictors. METHODS: A cross-sectional survey was conducted, including parasitological examinations and interviews with more than 5,000 children from 93 schools across Côte d'Ivoire. A finger-prick blood sample was obtained from each child to determine Plasmodium species-specific infection and parasitaemia using Giemsa-stained thick and thin blood films. Household socioeconomic status was assessed through asset ownership and household characteristics. Children were interviewed for preventive measures against malaria. Environmental data were gathered from satellite images and digitized maps. A Bayesian geostatistical stochastic search variable selection procedure was employed to identify factors related to P. falciparum infection risk. Bayesian geostatistical logistic regression models were used to map the spatial distribution of P. falciparum infection and to predict the infection prevalence at non-sampled locations via Bayesian kriging. RESULTS: Complete data sets were available from 5,322 children aged 5-16 years across Côte d'Ivoire. P. falciparum was the predominant species (94.5 %). The Bayesian geostatistical variable selection procedure identified land cover and socioeconomic status as important predictors for infection risk with P. falciparum. Model-based prediction identified high P. falciparum infection risk in the north, central-east, south-east, west and south-west of Côte d'Ivoire. Low-risk areas were found in the south-eastern area close to Abidjan and the south-central and west-central part of the country. CONCLUSIONS: The P. falciparum infection risk and related uncertainty estimates for school-aged children in Côte d'Ivoire represent the most up-to-date malaria risk maps. These tools can be used for spatial targeting of malaria control interventions

Species composition and insecticide resistance in malaria vectors in Ellibou, southern Côte d'Ivoire and first finding of; Anopheles arabiensis; in Côte d'Ivoire

Background Knowing the species composition and insecticide resistance status of the target vector population is important to guide malaria vector control. The aim of this study was to characterize the malaria vector population in terms of species composition, insecticide susceptibility status and potential underlying resistance mechanisms in Ellibou, southern Côte d'Ivoire. Methods A 1-year longitudinal entomological survey was conducted using light traps and pyrethroid spray catches to sample adult mosquitoes in combination with larval sampling. The susceptibility status of Anopheles gambiae sensu lato (s.l.) to bendiocarb, deltamethrin, DDT and malathion was assessed using the World Health Organization insecticide susceptibility test. Additionally, An. gambiae specimens were screened for knockdown (kdr) and acetylcholineesterase (ace1) target site resistance alleles, and the expression levels of eight metabolic resistance genes, including seven cytochrome P450 monooxygenases (P450s) and one glutathione S-transferase (GST), measured with reverse transcription quantitative real-time polymerase chain reaction (qPCR). Results Overall, 2383 adult mosquitoes from 12 different taxa were collected with Culex quinquefasciatus and An. gambiae being the predominant taxa. Molecular identification of An. gambiae s.l. revealed the presence of Anopheles arabiensis, Anopheles coluzzii, An. gambiae sensu stricto (s.s.) and Anopheles coluzzii/An. gambiae s.s. hybrids. Anopheles gambiae mosquitoes were resistant to all insecticides except malathion. PCR diagnostics revealed the presence of ace1-G280S and the kdr L995F, L995S and N1570Y target-site mutations. Additionally, several genes were upregulated, including five P450s (i.e., CYP6P3, CYP6M2, CYP9K1, CYP6Z1, CYP6P1) and GSTE2. Conclusion This is the first documented presence of An. arabiensis in Côte d'Ivoire. Its detection - together with a recent finding further north of the country - confirms its existence in the country, which is an early warning sign, as An. arabiensis shows a different biology than the currently documented malaria vectors. Because the local An. gambiae population was still susceptible to malathion, upregulation of P450s, conferring insecticide resistance to pyrethroids, together with the presence of ace1, suggest negative cross-resistance. Therefore, organophosphates could be an alternative insecticide class for indoor residual spraying in the Ellibou area, while additional tools against the outdoor biting An. arabiensis will have to be considered

Rapid high throughput SYBR green assay for identifying the malaria vectors Anophelese arabiensis, Anopheles coluzzii and Anopheles gambia s.s. Giles

The Anopheles gambiae sensu lato species complex consists of a number of cryptic species with different habitats and behaviours. These morphologically indistinct species are identified by chromosome banding. Several molecular diagnostic techniques for distinguishing between An. coluzzii and An. gambiae are still under improvement. Although, the current SINE method for identification between An. coluzzii and An. gambiae works reliably, this study describes a refinement of the SINE method to increase sensitivity for identification of An. coluzzii, An. gambiae and An. arabiensis based on amplicon dissociation curve characteristics. Field-collected samples, laboratory-reared colonies and crossed specimens of the two species were used for the design of the protocol. An. gambiae, An. coluzzii, and hybrids of the two species were sampled from Ghana and An. arabiensis from Kenya. Samples were first characterised using conventional SINE PCR method, and further assayed using SYBR green, an intercalating fluorescent dye. The three species and hybrids were clearly differentiated using the melting temperature of the dissociation curves, with derivative peaks at 72˚C for An. arabiensis, 75˚C for An. gambiae and 86˚C for An. coluzzii. The hybrids (An. gambiae / An. coluzzii) showed both peaks. This work is the first to describe a SYBR green real time PCR method for the characterization of An. arabiensis, An. gambiae and An. coluzzii and was purposely designed for basic melt-curve analysis (rather than high-resolution melt-curve) to allow it to be used on a wide range of real-time PCR machines

A Trial of Early Antiretrovirals and Isoniazid Preventive Therapy in Africa

BACKGROUND: In sub-Saharan Africa, the burden of human immunodeficiency virus (HIV)-associated tuberculosis is high. We conducted a trial with a 2-by-2 factorial design to assess the benefits of early antiretroviral therapy (ART), 6-month isoniazid preventive therapy (IPT), or both among HIV-infected adults with high CD4+ cell counts in Ivory Coast. METHODS: We included participants who had HIV type 1 infection and a CD4+ count of less than 800 cells per cubic millimeter and who met no criteria for starting ART according to World Health Organization (WHO) guidelines. Participants were randomly assigned to one of four treatment groups: deferred ART (ART initiation according to WHO criteria), deferred ART plus IPT, early ART (immediate ART initiation), or early ART plus IPT. The primary end point was a composite of diseases included in the case definition of the acquired immunodeficiency syndrome (AIDS), non-AIDS-defining cancer, non-AIDS-defining invasive bacterial disease, or death from any cause at 30 months. We used Cox proportional models to compare outcomes between the deferred-ART and early-ART strategies and between the IPT and no-IPT strategies. RESULTS: A total of 2056 patients (41% with a baseline CD4+ count of ≥500 cells per cubic millimeter) were followed for 4757 patient-years. A total of 204 primary end-point events were observed (3.8 events per 100 person-years; 95% confidence interval [CI], 3.3 to 4.4), including 68 in patients with a baseline CD4+ count of at least 500 cells per cubic millimeter (3.2 events per 100 person-years; 95% CI, 2.4 to 4.0). Tuberculosis and invasive bacterial diseases accounted for 42% and 27% of primary end-point events, respectively. The risk of death or severe HIV-related illness was lower with early ART than with deferred ART (adjusted hazard ratio, 0.56; 95% CI, 0.41 to 0.76; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.56; 95% CI, 0.33 to 0.94) and lower with IPT than with no IPT (adjusted hazard ratio, 0.65; 95% CI, 0.48 to 0.88; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.61; 95% CI, 0.36 to 1.01). The 30-month probability of grade 3 or 4 adverse events did not differ significantly among the strategies. CONCLUSIONS: In this African country, immediate ART and 6 months of IPT independently led to lower rates of severe illness than did deferred ART and no IPT, both overall and among patients with CD4+ counts of at least 500 cells per cubic millimeter. (Funded by the French National Agency for Research on AIDS and Viral Hepatitis; TEMPRANO ANRS 12136 ClinicalTrials.gov number, NCT00495651.)

Effect of isoniazid preventive therapy on risk of death in west African, HIV-infected adults with high CD4 cell counts: long-term follow-up of the Temprano ANRS 12136 trial.

BACKGROUND: Temprano ANRS 12136 was a factorial 2 × 2 trial that assessed the benefits of early antiretroviral therapy (ART; ie, in patients who had not reached the CD4 cell count threshold used to recommend starting ART, as per the WHO guidelines that were the standard during the study period) and 6-month isoniazid preventive therapy (IPT) in HIV-infected adults in Côte d'Ivoire. Early ART and IPT were shown to independently reduce the risk of severe morbidity at 30 months. Here, we present the efficacy of IPT in reducing mortality from the long-term follow-up of Temprano. METHODS: For Temprano, participants were randomly assigned to four groups (deferred ART, deferred ART plus IPT, early ART, or early ART plus IPT). Participants who completed the trial follow-up were invited to participate in a post-trial phase. The primary post-trial phase endpoint was death, as analysed by the intention-to-treat principle. We used Cox proportional models to compare all-cause mortality between the IPT and no IPT strategies from inclusion in Temprano to the end of the follow-up period. FINDINGS: Between March 18, 2008, and Jan 5, 2015, 2056 patients (mean baseline CD4 count 477 cells per μL) were followed up for 9404 patient-years (Temprano 4757; post-trial phase 4647). The median follow-up time was 4·9 years (IQR 3·3-5·8). 86 deaths were recorded (Temprano 47 deaths; post-trial phase 39 deaths), of which 34 were in patients randomly assigned IPT (6-year probability 4·1%, 95% CI 2·9-5·7) and 52 were in those randomly assigned no IPT (6·9%, 5·1-9·2). The hazard ratio of death in patients who had IPT compared with those who did not have IPT was 0·63 (95% CI, 0·41 to 0·97) after adjusting for the ART strategy (early vs deferred), and 0·61 (0·39-0·94) after adjustment for the ART strategy, baseline CD4 cell count, and other key characteristics. There was no evidence for statistical interaction between IPT and ART (pinteraction=0·77) or between IPT and time (pinteraction=0·94) on mortality. INTERPRETATION: In Côte d'Ivoire, where the incidence of tuberculosis was last reported as 159 per 100 000 people, 6 months of IPT has a durable protective effect in reducing mortality in HIV-infected people, even in people with high CD4 cell counts and who have started ART. FUNDING: National Research Agency on AIDS and Viral Hepatitis (ANRS)

Marché et commercialisation du riz local au Centre-Ouest de la Côte d\'Ivoire.

Face à une augmentation de la demande pour le riz et à une production nationale plus ou moins stable depuis 1980, la Côte d\'Ivoire déploie beaucoup d\'efforts dans la riziculture, notamment dans les bas-fonds. La présente étude vise à analyser l\'efficacité des systèmes de commercialisation de riz local. La coexistence de trois grands circuits de commercialisation a été révélée : cycles court, moyen et long. Globalement, le marché est certes concurrentiel, mais on note des pratiques monopolistiques et oligopolistiques de certains intermédiaires commerciaux. Le prix du riz varie dans le temps et l\'espace, et est dominé par les marges bénéficiaires. En outre, une proportionnalité existe entre les marges et les charges supportées par les différents opérateurs.Faced with a growing demand for rice, and a national rice production, which has not increased since 1980, Côte d\'Ivoire is presently investing considerable effort in the development of rice culture, specially in inland valleys. The objective of the present study is to examine local marketing systems. The results show that there were three channels of distribution : (short, medium and long). The market was characterized by an unperfect concurrence, because of monopolistic and oligopolistic practices of some middlemen. The price of local rice was very variable in space and time. Margins and costs were quite proportional. Keywords: Riz, commercialisation, circuit de distribution, intermédiaires, demande, Côte d\'IvoireAgronomie Africaine Vol. 18 (3) 2006: pp. 299-30

Effect of deworming on school-aged children's physical fitness, cognition and clinical parameters in a malaria-helminth co-endemic area of Côte d'Ivoire

Malaria and helminth infections are thought to negatively affect children's nutritional status and to impair their physical and cognitive development. Yet, the current evidence-base is weak. The purpose of this study was to determine the effect of deworming against soil-transmitted helminthiasis and schistosomiasis on children's physical fitness, cognition and clinical parameters in a malaria-helminth co-endemic setting of Côte d'Ivoire.; We designed an intervention study with a 5-month follow-up among schoolchildren aged 5-14 years from Niablé, eastern Côte d'Ivoire. In late 2012, a baseline cross-sectional survey was conducted. Finger-prick blood, stool and urine samples were subjected to standardised, quality-controlled techniques for the diagnosis of Plasmodium spp., Schistosoma spp., soil-transmitted helminths and intestinal protozoa infections. Haemoglobin level was determined and anthropometric measurements were taken for appraisal of anaemia and nutritional status. Children underwent memory (digit span) and attention (code transmission) cognitive testing, and their physical fitness and strength were determined (20 m shuttle run, standing broad jump and grip strength test). All children were treated with albendazole (against soil-transmitted helminthiasis) and praziquantel (against schistosomiasis) after the baseline cross-sectional survey and again 2 months later. Five months after the initial deworming, the same battery of clinical, cognitive and physical fitness tests was performed on the same children.; Lower scores in strength tests were significantly associated with children with harbouring nutritional deficiencies. Surprisingly, boys infected with Schistosoma mansoni achieved longer jumping distances than their non-infected counterparts. Light-intensity infection with S. mansoni was associated with slightly better aerobic capacity. Deworming showed no effect on haemoglobin levels and anaemia, but children with moderate- to heavy-intensity Schistosoma infection at baseline gained weight more pronouncedly than non-infected children. Interestingly, children with soil-transmitted helminth or Schistosoma infection at baseline performed significantly better in the sustained attention test than their non-infected counterparts at the 5-month follow-up.; This study revealed conflicting results regarding clinical parameters and cognitive behaviour of children after two rounds of deworming. We speculate that potential beneficial effects of deworming are likely to be undermined in areas where malaria is co-endemic and nutritional deficiencies are widespread

La pisciculture continentale dans la région du Gontougo (Côte d'Ivoire): Caractérisation et aspects socio-économiques

Continental Fish Farming in the Gontougo Area (Ivory Coast): Characterization and Socio-economic Aspects. This study aims at identifying the current state of fish farming in the area of Gontougo. It was carried out from May to September 2013 using a questionnaire and individual interview with fish farmers. The results showed that all producers practiced artisanal fish farming and this activity played an important socio-economic role. Fish farming is exclusively carried out by local people belonging mainly to the Abron ethnic group (77.8%). This activity is mainly practiced by people aged 45 years and over (77.8%). It was observed that 41.7% of the ponds are in derivation while 58.3% are barrage ponds. Oreochromis niloticus Linné, 1758 and Heterobranchus longifilis Valenciennes, 1840 are the most reared fish species. The total fish production in 2012 was estimated to 3,552.5 kg in 68 ponds. The produced quantities vary from a fish farmer to another, with an average production of 592.1±635.9 kg/fish farmer/year. All fish farmers (100%) feed the fish with agricultural by-products. They have difficulties to feed them properly. They didn't receive funding, coaching and training. Some fish farmers (33.3%) faced water problem. All these factors are an obstacle to sustainable management of fish farming in this area