Moustiquaires imprégnées d'insecticides longue durée et tests diagnostiques rapides du paludisme : implication dans le contrôle du paludisme au centre de la Côte d'Ivoire

Malaria is a vector-borne disease that primarily affects rural dwellers in the tropics and subtropics. In areas of high transmission, the highest mortality and morbidity rates are found in rural settings with seasonal variations that might be governed by irrigated rice farming. The use of long-lasting insecticidal nets (LLINs), adequate case management facilitated by rapid diagnostic tests (RDTs) and prompt treatment with artemisinin-based combination therapy are key tools for malaria control. The effectiveness of these control measures might be further enhanced by the implementation of communication strategies aiming at increasing population LLINs ownership. We evaluated the effect of routine LLINs monitoring and active surveillance of Plasmodium falciparum infection using RDTs and treatment administration at the community level on malaria transmission, infection and morbidity. Additionally, the acceptability of RDTs for malaria was investigated. Goal and specific objectives This PhD pursued four specific objectives: (i) to evaluate the effect of LLINs on species composition and abundance of wild Culicidae; (ii) to evaluate the impact of LLINs routine monitoring on transmission indicators; (iii) to evaluate the impact of LLINs routine monitoring associated with the detection of malaria cases using RDTs on malaria prevalence and morbidity; and (iv) to determine socio-economic factors impacting the use of LLINs and identify attitudes and beliefs affecting RDTs acceptability. Methods The study was carried out between July 2009 and May 2012 in three villages (N’dakonankro, Yoho and Bozi) in central Côte d’Ivoire. In Bozi, 150 households were given LLINs free of charge. Five entomological surveys (collection of larvae and adult mosquitoes) were conducted: two before and three after free distribution of LLINs at 3-month intervals. Three parasitological surveys (examination of Giemsa-stained thick and thin blood films and RDTs) were carried out: one prior to and two after free LLIN distribution at 6-month intervals. Additionally, two socio-cultural and economic surveys using a questionnaire were carried out. Results The results of our study showed that longitudinal monitoring and implementing a locally adapted communication strategy at the household level were associated with reduced malaria transmission and lower P. falciparum prevalence rates. The adherence of the population to properly use LLINs increased net utilization to very high levels (95-100%). While a rapid decrease in malaria transmission in Bozi was observed, declines in malaria incidence and prevalence required longer time. Our results highlight the scope and limitations of implementing local malaria control measures. A significant relationship between people’s educational attainment, socio-economic position and nets ownership have been observed. In addition social representations about malaria, blood and blood-related diseases preventing an efficient introduction and routine use of RDTs have been found. Conclusions In central Côte d’Ivoire, scaling up and sustained use of LLINs should be carefully monitored at the household level. Moreover, the integration of larval control holds promise to significantly reducing malaria transmission. Specific health messages tailored to the local context should be used to raise awareness about the use of RDTs for malaria. Remaining challenges (e.g. strategies adapted to the local conditions of information, education and communication, and diagnosis and prevention) must be overcome for integrated control and eventual local elimination of malaria

Effets de deux plantes aphrodisiatiques africaines Garcinia kola et Turraea heterophylla sur les performances zootechniques et le taux d’inversion sexuelle chez Oreochromis niloticus

Dans le but développer une méthode alternative au 17-α -méthytestostérone, les effets de Garcinia kola et Turraea heterophylla sur la production des alevins monosexes mâles de Oreochromis niloticus ont été évaluées. Ainsi, 7200 alevins (0,011 ± 0,002 g) ont été répartis dans 24 happas en raison de 300 poissons/happa, formant 8 traitements en triplicata. Huit régimes alimentaires correspondant chacun à un traitement ont été testés. Les régimes témoins négatif et positif contiennent respectivement 0 et 70 mg de méthyltestostérone/kg. Six régimes dont 3 par plante, contiennent respectivement 10, 20 et 30 g d’extrait/kg. Les lots « lot 10g » et « lot 30g » de T. heterophylla présentent respectivement les meilleures croissances et taux de mâle. Les taux optimaux d’extraits sont de 10 et 30 g/kg respectivement pour la croissance et masculinisation. L’augmentation du pourcentage de mâles est dose-dépendante. Les fortes proportions de mâles sont de 76,82 ± 3,34 % pour T. heterophylla et 65,75 ± 4,19 % pour G. kola. Les meilleurs poids moyens enregistrés pour T. heterophylla et G. kola sont respectivement de 0,919 ± 0,059 et 0,663 ± 0,103 g. Les taux de survie sont compris entre 88 et 95 %. Des études complémentaires détermineront les méthodes d’application, les solvants d’extraction et la durée de traitement appropriés à la production d’alevins monosexes mâles.Mots-clés : Oreochromis niloticus, Plantes aphrodisiaques, Inversion sexuelle, Paramètres zootechniques, Côte d’Ivoire

Water quality and water-use conflicts in Lake Taabo (Ivory Coast)

The Lake Taabo (Ivory Coast, Africa) results of the construction of the Taabo dam on the Ban- dama River. The changes in the water level of the 69-km² lake depend on 1) the rainfall linked to alternating dry/wet seasons; 2) the extraction of water for human uses; 3) the discharge of water from the upstream dam and the volumes tur- bined by the Kossou dam; 4) the various an- thropic effects (discharge of untreated waste water from towns and industries, and leaching from agricultural land). The average concentra- tions of nutrients (NH4-N: 1.1 mg/L, NO3-N: 1.62 mg/L, PO4-P: 10 mg/L, SiO2: 15 mg/L) and chlo- rophyll a (from 4.8 to 16.5 μg/L, average 11.4 μg/L) indicates some degree of eutrophication. The cumulated effects that threaten the ecosys- tem (degradation of water quality and eutrophi- cation) are such that they are likely to interfere with various water uses. In a context of growing health and environmental concerns in Africa, this study demonstrates conflicts between dif- ferent uses of this water resource and the urgent need for an appropriate policy including specific monitoring of lake water quality, wastewater control, and a programme to reduce agricultural fertilizers

Performances Économiques Comparées Des Unités De Pêche En Lagune Et Des Alternatives Agricoles Et Aquacoles À Grand-Lahou (Côte d’Ivoire)

The lagoons are high biological and economic potential areas exploited by thousands of fishermen. Otherwise, the persistent use of pesticides in fisheries may be perceived as a response of fishermen to lower yields and, consequently, to reduced income from fishing activities. In this context, the hypothesis of a lack of profitability concerning the activity of professional fishermen was therefore raised. To reach this goal, a market survey, investments and fish landings were carried out in order to analyze the profitability and economic performance of this activity. It recorded 5227 catch exits from a sample of 35 fixed fishermen in 7 villages. These were followed 15 times a month for 12 months whenever possible. In practice, approximately 60% of the suspected activity of professional fishermen has been observed. After elaborating the annual operating accounts and calculating the performance ratios, it appears that the lagoon fishing activity of Grand-Lahou is profitable and competitive compared to the alternative economic activities of the study area. However, performance is not homogeneous between villages. This suggests a fishing-related effect on fishers' performance. In addition, it is the Liza falcipinnis and Chrysichthys nigrodigitatus species that significantly influence the value of production and hence income

Malaria knowledge and long-lasting insecticidal net use in rural communities of central Côte d'Ivoire

ABSTRACT: BACKGROUND: To improve effectiveness of malaria control interventions, it is essential to deepen the knowledge of contextual factors that govern people's practice for preventive and curative measures. The aim of this study was to determine factors that influence the use of long-lasting insecticidal nets (LLINs) in three rural communities of Cote d'Ivoire, two of which benefited from recent interventions. METHODS: The study was carried out in 957 households in three villages (Bozi, N'Dakonankro and Yoho) located in central Cote d'Ivoire. Indicators of socioeconomic position (SEP), malaria knowledge and practice, placing special emphasis on LLINs, were investigated during a cross-sectional questionnaire survey. Principal component analysis was used to calculate the SEP of households by means of a list of household assets ownership. The concentration index was used to assess the direction of the association between SEP and a given variable. To compare groups or means, Fisher's exact test, chi2 and Kruskal-Wallis test were used, as appropriate. RESULTS: Significant differences were found between SEP and reported malaria symptoms, such as fever or hot body, convulsion, anaemia and jaundice (yellow eyes). Individuals from the least poor group cited more often the use of bed nets and insecticide-treated nets (ITNs) compared to poorer groups. The mean number of individuals reporting the use of bed nets and LLINs was different between groups with different educational level. Moreover, the mean number of LLINs in a household was influenced by the presence of children below five years of age. CONCLUSION: The study not only confirmed that education and SEP play important roles in the prevention and control of malaria and promotion of health in general, but pointed at the basic essential knowledge and the key behavioural elements that should guide education and learning processes among the poorer segments of the population. In turn, such knowledge may change behaviour and lead to an increased utilization of LLIN

Pharmacokinetics, safety, and efficacy of a single co-administered dose of diethylcarbamazine, albendazole and ivermectin in adults with and without Wuchereria bancrofti infection in Cote d\u27Ivoire

BackgroundA single co-administered dose of ivermectin (IVM) plus diethylcarbamazine (DEC) plus albendazole (ALB), or triple-drug therapy, was recently found to be more effective for clearing microfilariae (Mf) than standard DEC plus ALB currently used for mass drug administration programs for lymphatic filariasis (LF) outside of sub-Saharan Africa. Triple-drug therapy has not been previously tested in LF-uninfected individuals from Africa. This study evaluated the pharmacokinetics (PK), safety, and efficacy of triple-drug therapy in people with and without Wuchereria bancrofti infection in West Africa.MethodsIn this open-label cohort study, treatment-naïve microfilaremic (>50 mf/mL, n = 32) and uninfected (circulating filarial antigen negative, n = 24) adults residing in Agboville district, Côte d’Ivoire, were treated with a single dose of IVM plus DEC plus ALB, and evaluated for adverse events (AEs) until 7 days post treatment. Drug levels were assessed by liquid chromatography and mass spectrometry. Persons responsible for assessing AEs were blinded to participants’ infection status.FindingsThere was no difference in AUC0-inf or Cmax between LF-infected and uninfected participants (P>0.05 for all comparisons). All subjects experienced mild AEs; 28% and 25% of infected and uninfected participants experienced grade 2 AEs, respectively. There were no severe or serious adverse events. Only fever (16 of 32 versus 4 of 24, PConclusionsModerate to heavy W. bancrofti infection did not affect PK parameters for IVM, DEC or ALB following a single co-administered dose of these drugs compared to uninfected individuals. The drugs were well tolerated. This study confirmed the efficacy of the triple-drug therapy for clearing W. bancrofti Mf and has added important information to support the use of this regimen in LF elimination programs in areas of Africa without co-endemic onchocerciasis or loiasis.Trial registrationClinicalTrials.gov NCT02845713.</div

Detectability and impact of repetitive surveys on threatened West African crocodylians

West African crocodylians are among the most threatened and least studied crocodylian species globally. Assessing population status and establishing a basis for population monitoring is the highest priority action for this region. Monitoring of crocodiles is influenced by many factors that affect detectability, including environmental variables and individual- or population-level wariness. We investigated how these factors affect detectability and counts of the critically endangered Mecistops cataphractus and the newly recognized Crocodylus suchus. We implemented 195 repetitive surveys at 38 sites across Côte d’Ivoire between 2014 and 2019. We used an occupancy-based approach and a count-based GLMM analysis to determine the effect of environmental and anthropogenic variables on detection and modeled crocodile wariness over repetitive surveys. Despite their rarity and level of threat, detection probability of both species was relatively high (0.75 for M. cataphractus and 0.81 for C. suchus), but a minimum of two surveys were required to infer absence of either species with 90% confidence. We found that detection of M. cataphractus was significantly negatively influenced by fishing net encounter rate, while high temperature for the previous 48 h of the day of the survey increased C. suchus detection. Precipitation and aquatic vegetation had significant negative and positive influence, respectively, on M. cataphractus counts and showed the opposite effect for C. suchus counts. We also found that fishing encounter rate had a significant negative effect on C. suchus counts. Interestingly, survey repetition did not generally affect wariness for either species, though there was some indication that at least M. cataphractus was more wary by the fourth replicate. These results are informative for designing future survey and monitoring protocols for these threatened crocodylians in West Africa and for other endangered crocodylians globally

Update on the current status of onchocerciasis in Cote d’Ivoire following 40 years of intervention: Progress and challenges

Background Onchocerciasis control in Côte d’Ivoire started with aerial insecticide spraying in 1974 and continued with community directed treatment with ivermectin (CDTi) from 1992 to the present. Onchocerciasis and lymphatic filariasis (LF) are co-endemic in 46 of the 81 health districts in the country. Fourteen and 12 districts are endemic for only LF or onchocerciasis, respectively. This paper aims to review the impact of past interventions on onchocerciasis in Côte d’Ivoire between 1975 and 2013, and review plans for disease elimination. Methods We reviewed microfilaria (MF, skin snip) prevalence and community microfilarial load (CMFL) data from published reports from 53 health districts during two major epidemiological assessment periods. Data from 1975 through 1991 provided information on the impact of vector control, and data from 1992 through 2016 provided information on the impact of CDTi. Results Weekly aerial insecticide spraying in 8 endemic districts between 1975 and 1991 reduced the overall MF prevalence by 68.1% from 43.5% to 13.9%. The CMFL also decreased in 7 out of 8 surveyed communities by 95.2% from 9.24 MF/snip to 0.44 MF/snip. Ivermectin distribution started in 1992. The coverage targets for control (65% of the total population) was reached in most endemic districts, and some areas achieved 80% coverage. Two sets of surveys were conducted to assess the impact of CDTi. Results from the first repeat surveys showed a significant decrease in overall MF prevalence (by 75.7%, from 41.6% to 10.1%). The second follow-up evaluation showed further improvement in most endemic districts and also documented major reductions in CMFL compared to baseline. Conclusions Extensive data collected over many years document the very significant impact of interventions conducted by the National Onchocerciasis and other Eyes Diseases Control Programme during challenging times with periods of civil unrest. The Health Ministry has now integrated efforts to control neglected tropical diseases and adopted the goal of onchocerciasis elimination

PREDVIĐANJE ČIMBENIKA KOJI UTJEČU NA SASTAV STRUKTURA RIBA U ČETIRI OBALNE RIJEKE (JUGOISTOČNA OBALA BJELOKOSTI) POMOĆU UMJETNIH NEURONSKIH MREŽA

The present study is focused on small coastal rivers in southeast Ivory Coast, aimed to predict species richness of fish guilds and to test contribution of environmental variables for explaining guild structure with Self- Organizing Map (SOM) and Backpropagation (BP) algorithms. The former method was applied to pattern the samples based on the richness of six major fish guilds observed (benthivores, invertivores, detritivores, piscivores, herbivores and omnivores). Four clusters were identified: cluster I was characterised by benthivores, cluster II was distinguished by invertivores, detritivores, piscivores and omnivores, cluster III had high richness of benthivores, invertivores and herbivores, and cluster IV had high numbers of omnivore, detritivore and piscivore species. The BP showed high predictability (0.89 for benthivores, 0.85 for omnivores and Odonata, 0.84 for herbivores). There was high correlation between observed and estimated values for piscivores (0.77) and detritivores (0.72); the poorest fit was for invertivores (0.63). The frequency histogram of residuals showed that most residuals lie around zero for all guilds. The most contributing variables in predicting the six fish trophic guilds were water temperature, conductivity, total dissolved solids, dissolved oxygen, depth, width, canopy and distance from source. This underlines the crucial influence of both instream characteristics and riparian environment.Ovo je istraživanje usmjereno prema malim obalnim rijekama na jugoistočnoj Obali Bjelokosti s ciljem predviđanja bogatstva vrsta riba i testiranjem doprinosa varijabli iz okolice kako bi se objasnila struktura populacija pomoću samoorganiziranih karata (SOM) i povratnih (BP) algoritama. Metoda je primijenjena na uzorku temeljenim na bogatstvu šest glavnih zabilježenih tipova ishrane (bentivori, invertivori, detrivori, piscivori, herbivori i omnivori). Identificirane su četiri skupine: klaster I je karakteriziran bentivorima, klaster II se odlikuje invertivorima, detrivorima, piscivorima i omnivorima, klaster III je bogat bentivorima, invertivorima i herbivorima, a klaster IV je imao visok broj omnivora, detrivora i piscivora. BP je pokazao visoku predvidljivost (0,89 za bentivore, 0,85 za omnivore i Odonata, 0,84 za herbivore). Visoka korelacija je zamijećena između promatranih i procijenjenih vrijednosti za piscivore (0,77) i detrivore (0,72), a najmanja za invertivore (0,63). Histogram pokazuje da se većina ostataka kreće oko nule za sve osobine. Varijable koje su najviše doprinijele predviđanju šest trofičkih ribljih struktura su temperatura vode, provodljivost, ukupno otopljene tvari, otopljeni kisik, dubina, širina, zasjenjenost i udaljenost od izvora. To naglašava presudan utjecaj karakteristika vodotoka i priobalnog okoliša