Pollution physico-chimique et bactériologique d’un écosystème aquatique et ses risques écotoxicologiques: Cas du lac Nokoue au Sud Benin

La protection des écosystèmes aquatiques est indispensable à l’équilibre écologique des espèces halieutiques et à une saine alimentation des populations locales. Le lac Nokoué situé au Sud du Bénin est sous l’influence de plusieurs formes de pollution qui résultent pour la plupart des activités anthropiques. Ce travail se propose de faire une évaluation des diverses formes de pollution que subi aujourd’hui ce lac, afin d’alerter sur les risques écotoxicologiques. Pour atteindre cet objectif, des visites du terrain d’étude, des analyses physico-chimiques et bactériologiques ont été effectuées, des entretiens avec des personnes ressources ont été organisés et des enquêtes de terrain ont été menées auprès des populations locales. Les résultats issus des analyses physico-chimiques et bactériologiques de l’eau du lac Nokoué ont permis d’identifier les sources des divers types de polluants du lac Nokoué. La teneur en oxygène dissous varie de 3,62 mg /L à 2,76 mg/L ; la DBO5 de 29 mg/L à 10 mg/L ; la DCO est de 253 mg/L ; la teneur en ammonium est supérieure à 8 mg/L ; la teneur en nitrite avoisine 0,7 mg /L par endroit ; la teneur en coliformes totaux fluctue de 4000 /100 mL à 6000/100 mL ; la teneur en streptocoques fécaux varie de 500/100mL à 4000/100 mL. Ces résultats montrent que le lac Nokoué est pollué. Des stratégies pour limiter la pollution du lac doivent être mises en place par les décideurs à tous les niveaux afin d’éviter des problèmes d’écosanté aux populations du lac Nokoué, ce qui pourrait constituer aussi un frein pour le développement du pays.Keywords: Pollution, écosystème, lac Nokoué, risques écotoxicologique

Evaluation de l’intensité territoriale de deux systèmes de cultures associées modérément fertilisées au Sud-Bénin

L’Afrique de l’Ouest demeure la région où l’accroissement de la production alimentaire est plus faible que la progression démographique avec une économie trop faible pour soutenir une agriculture moderne, consommatrice d’intrants et d’énergie. Ainsi, l’une des alternatives pourrait être une amélioration des systèmes de cultures multiples, encore en usage dans la région. Pour ce faire, deux expérimentations basées sur un apport d’engrais NPK (10-20-20) et 10 t de matière organique/ha, ont été conduites à Kpotomey au Bénin. L’une a associé l’arachide et trois variétés de maïs et l’autre a combiné le maïs, le manioc et le pois d’angole. L’objectif a été d’évaluer la productivité des différents systèmes de cultures étudiés par rapport à la superficie nécessaire pour satisfaire les besoins alimentaires. Les résultats montrent que l’intensité territoriale a varié de 2 831,4 m2 à 495,6 m2 pour les associations impliquant l’arachide et le maïs et de 25 000 m2 à 266,6 m2 pour celles basées sur le maïs, le manioc et le pois d’angole. Il est alors nécessaire de s’appuyer sur la minimisation de l’intensité territoriale afin de concilier au mieux la satisfaction des besoins alimentaires des populations et la préservation des terres arables qui constituent des ressources naturelles non extensibles. Mots clés : intensité territoriale, cultures associées, besoins alimentaire

Survey and cartography of the spatial variation of the pollution of the waters from well of some districts of the township of Abomey-Calavi, Benin

Objective: The objective of this work was conducted to study and map the spatial variation of the physical, chemical and microbiological  contamination of well water in some areas of the town of Abomey-Calavi inBenin.Methods and Results: The methods used to measure physical and  chemical parameters are those spectrophotometric, colorimetric, conductivity and some other methods recommended by the French Association for Standardization (AFNOR). Microbiological parameters were measured according to the method by incorporating agar described in the book Rodier and maps were produced by Arc View 3.2 software. On the physical and chemical level, 50% of the analyzed well water have a normal pH and are all located at the lake. All analyzed well water has a redox potential higher than normal with the highest values for wells along the lake. Lead and zinc concentrations in these waters comply with WHO standards. Bacteriological analyzes showed that all well water pollution reveal bacteria such as thermotolerant coliforms, intestinal enterococci, total coliforms with the highest concentrations in the wells located on LakeNokoué. This indicates that the water may be responsible for the spread of waterborne diseases. The ratio thermotolerant coliforms and intestinal enterococci show that the origin of faecal contamination of human type in 50% of the wells. Faecal contamination of human kind concerns all the lake nearby well and the animal type concerns distant wells that lake.Conclusion and Application: These cards will attract the attention of people in the town of Abomey-Calavi and policy makers on areas where well water are the most polluted.Key words: physical chemical and microbiological quality, well water, pollution, mapping

Etude Des Facteurs De Risque De L’obésité Chez Le Personnel Du CHUD/Borgou à Parakou (Bénin) en 2013

The objective of this study was to determine the prevalence of obesity among employees CHUD in Parakou and risk factors in 2013. Methods: This was a cross sectional study, descriptive analytical referred to place from 05 August to 05 September 2013. The study population consists of employees of CHUD in Parakou. Data were collected using a questionnaire and by anthropometric measures. Results: The overall prevalence of overweight and obesity was 55.9%. The sex ratio was 0.8. The mean age of subjects was 37.2 ± 9.0 years. Factors associated with obesity were: female gender (p = 10-11), those aged 30-49 years (p = 0.04), subjects with a level of secondary education limited (p = 0.01), subjects with a daily consumption and accidental alcohol (p = 10-9), snacking (p = 0.00012). Conclusion: Obesity prevention should involve the establishment and maintenance during the lifetime of healthy eating habits and regular physical activity

Issue Thérapeutique Des Patients Tuberculeux Pulmonaires Biologiquement Confirmés Dans La Zone Sanitaire De Parakou-N’Dali De 2011 À 2015

Objective: The objective of this study is to describe the therapeutic outcome and factors associated with treatment failure in laboratory confirmed pulmonary tuberculosis patients. Methods: He acted in a descriptive and analytical study referred to prospective data collection. The study population consisted of laboratory confirmed pulmonary tuberculosis patients in the health zone Parakou-N'Dali from 2011 to 2015. Results: A total of 313 TB patients were enrolled. The average age of patients was 37.4 ± 14.3 years. The sex ratio was 2.1. Two hundred sixtyfive (265) patients were cured, a cure rate of 84.66%; 5 patients had completed treatment. Therapeutic success was observed in 270 patients (86.26%); the rate of treatment failure was 2.24%. Twenty-nine (29) patients died (9.26%); 6 patients were lost to follow and only 1 was transferred. Factors associated with treatment failure were the BMI screening to the lower than 18.5 kg/m2 (p = 0.000) and hospitalization (p = 0.002).Conclusion: The therapeutic outcome of patients with pulmonary tuberculosis in the health zone Parakou-N'Dali was characterized by a low rate process complete, lost sight and transfers

Gale en milieu carceral a Parakou (Benin) en 2019 : Prevalence et facteurs associes : Scabies in prisons in Parakou, Benin in 2019: Prevalence and associated factors

Objectif : L’objectif était de déterminer la prévalence et les facteurs associés à la gale en milieu carcéral à Parakou en 2019.Patients et méthodes : Il s’est agi d’une étude transversale descriptive, qui s’est déroulé dans la Prison Civile de Parakou en 2019.Résultats : Sur 230 détenus examinés, 137 (59,57%) étaient atteints de gale. La tranche d’âge la plus touchée était celle de 18 à 27 ans, soit 37,39%. La prédominance était masculine avec une sex-ratio à 6,93. Les détenus ne se lavaient pas de façon quotidienne, plus de la moitié (76,96%) se lavaient 4 à 7 fois seulement par semaine. Le prurit était le signe le plus fréquent. La région inguinale était le siège le plus atteint (61,31%). Le sexe (p=0,007), l’hygiène corporelle (p=0,001) et changement de vêtement (p=0,01) étaient associés à la gale à la Prison Civile de Parakou.Conclusion : La scabiose est fréquente à la Prison Civile de Parakou. Les facteurs associés à la survenue de la gale dans la prison de Parakou étaient le sexe, le manque d’hygiène. La connaissance et la prise en compte de ces facteurs de risque de la gale permettra de réduire significativement la fréquence de la gale en milieu carcéral au Bénin. Objective: The objective was to determine the prevalence and factors associated with scabies in prisons in Parakou in 2019.Patients and Methods: This was a descriptive cross-sectional study, which took place in the Civil Prison of Parakou in 2019.Results: Out of 230 inmates examined, 137 (59.57%) had scabies. The most affected age group was 18 to 27 years old, 37.39%. The predominance was male with a sex ratio of 6.93. The inmates did not wash daily, more than half (76.96%) washed only 4 to 7 times a week. Pruritus was the most frequent sign. The inguinal region was the most affected site (61.31%). Sex (p=0.007), body hygiene (p=0.001) and change of clothing (p=0.01) were associated with scabies in the Civil Prison of Parakou.Conclusion: Scabiosis is common in the Civil Prison of Parakou. The factors associated with the occurrence of scabies in the prison of Parakou were sex, lack of hygiene. Knowledge and consideration of these risk factors for scabies will significantly reduce the frequency of scabies in prisons in Benin

Minimal tillage and intermittent flooding farming systems show a potential reduction in the proliferation of Anopheles mosquito larvae in a rice field in Malanville, Northern Benin

Background Irrigation systems have been identified as one of the factors promoting malaria disease around agricultural farms in sub-Saharan Africa. However, if improved water management strategy is adopted during rice cultivation, it may help to reduce malaria cases among human population living around rice fields. This study aimed to assess the impact of the different irrigation practices on malaria transmission, as well as to evaluate the water management system that will best mitigate malaria transmission in Malanville, Benin. Methods Knowledge, Attitude and Practice (KAP) study was conducted on 104 households staying on and around the rice fields in Malanville. The study focused on the frequency of mosquito bites and preventive measures against malaria as well as soil preparation and rice planting methods. Mosquito larvae density was assessed in different water management system: continuous flooding (CF) or intermittent flooding (IF), deep tillage (DT) or minimal tillage (MT) and normal levelling (NL) or abnormal levelling (AL) in an experimental hut set-up. Larvae were collected using dipping methods and their density was determined. Results Three tillage systems, which include the use of tiller, plow and hoe, were identified on the rice field. Continuous flooding was the only irrigation system used by farmers. Retrospective data from Malanville Health Centre revealed higher malaria cases during rice production season, which was also confirmed by field participants. The density ofAnopheleslarvae was reduced by 80.8%, 30.8% and 40.7% (P = 0.000) during transplanting, tillering and maturation periods, respectively with intermittent flooding compared to continuous flooding. In addition, a clear reduction of larva density was observed with both intermittent flooding systems applied to minimal tillage (MT + IF + NL) and intermittent flooding applied to deep tillage (DT + IF + AL), showing that intermittent flooding could reduce the abundance of malaria vector in rice fields. Conclusion Recommending intermittent flooding technology for rice cultivation may not only be useful for water management but could also be an intentional strategy to control mosquitoes vector-borne diseases around rice farms