Distribution of ace-1R and resistance to carbamates and organophosphates in Anopheles gambiae s.s. populations from Côte d'Ivoire

<p>Abstract</p> <p>Background</p> <p>The spread of pyrethroid resistance in <it>Anopheles gambiae s.s. </it>is a critical issue for malaria vector control based on the use of insecticide-treated nets. Carbamates and organophosphates insecticides are regarded as alternatives or supplements to pyrethroids used in nets treatment. It is, therefore, essential to investigate on the susceptibility of pyrethroid resistant populations of <it>An. gambiae s.s. </it>to these alternative products.</p> <p>Methods</p> <p>In September 2004, a cross sectional survey was conducted in six localities in Côte d'Ivoire: Toumbokro, Yamoussoukro, Toumodi in the Southern Guinea savannah, Tiassalé in semi-deciduous forest, then Nieky and Abidjan in evergreen forest area. <it>An. gambiae </it>populations from these localities were previously reported to be highly resistant to pyrethroids insecticides. Anopheline larvae were collected from the field and reared to adults. Resistance/susceptibility to carbamates (0.4% carbosulfan, 0.1% propoxur) and organophosphates (0.4% chlorpyrifos-methyl, 1% fenitrothion) was assessed using WHO bioassay test kits for adult mosquitoes. Then, PCR assays were run to determine the molecular forms (M) and (S), as well as phenotypes for insensitive acetylcholinesterase (AChE1) due to G119S mutation.</p> <p>Results</p> <p>Bioassays showed carbamates (carbosulfan and propoxur) resistance in all tested populations of <it>An. gambiae s.s. </it>In addition, two out of the six tested populations (Toumodi and Tiassalé) were also resistant to organophosphates (mortality rates ranged from 29.5% to 93.3%). The M-form was predominant in tested samples (91.8%). M and S molecular forms were sympatric at two localities but no M/S hybrids were detected. The highest proportion of S-form (7.9% of <it>An. gambiae </it>identified) was in sample from Toumbokro, in the southern Guinea savannah. The G119S mutation was found in both M and S molecular forms with frequency from 30.9 to 35.2%.</p> <p>Conclusion</p> <p>This study revealed a wide distribution of insensitive acetylcholinesterase due to the G119S mutation in both M and S molecular forms of the populations of <it>An. gambiae s.s. </it>tested. The low cross-resistance between carbamates and organophosphates highly suggests involvement of other resistance mechanisms such as metabolic detoxification or F290V mutation.</p

Study of water pollution by agricultural inputs: case of five intensive agriculture areas in Burkina Faso

Pour optimiser les rendements (agricoles), l’agriculture intensive nécessite une utilisation massive d’intrants agricoles dont les engrais chimiques, potentiellement sources de pollution des ressources en eau. La région du Sud - Ouest du Burkina, dont font partie les zones concernées par la présente étude, connaît une agriculture intensive du coton. Il est fait usage dans les champs de coton, d’engrais à base essentiellement d’azote, de phosphate, de potassium, mais également d’urée, de chlorure de potassium et de nitrate d’ammonium. Un total de 42 échantillons d’eau de surface, de puits et de forages ont fait l’objet d’analyses, afin d’évaluer l’impact de ces engrais sur la qualité des ressources en eau de consommation des populations sur une année. Eu égard à la nature des fertilisants utilisés, les paramètres essentiels suivants ont été ciblés : Nitrates, nitrites, ortho-phosphates, ammonium, potassium, conductivité électrique et dureté totale. Il ressort de ces investigations que les eaux de puits, pendant la saison hivernale, présentent des teneurs plus importantes en nitrates et potassium avec des valeurs maximales respectives de 178 mg/L (plus de 3 fois la valeur limite admise par l’OMS pour les eaux de consommation) et 55 mg/L pour une norme admise par l’OMS de 10 mg/L en potassium. Les ortho-phosphates, forme soluble du phosphore et les nitrites, présentent des teneurs inférieures aux normes admises. S’agissant des ions ammonium, un seul puits par sa position en aval d’un WC et d’un parc d’animaux, a donné des valeurs supérieures à la norme qui est fixée à 1,5 mg/L, atteignant ainsi 20 mg/L de N-NH+4. Les échantillons d’eau de forages sont exempts de toute contamination, alors que 33% des prélèvements d’eau de surface ont donné des teneurs dépassant la valeur limite admise seulement en potassium. Globalement, 61% des échantillons d’eau de puits sont contaminés par les nitrates, 67% par le potassium et 17% donnent des teneurs supérieures à la norme en ammonium. Ce qui permet d’en déduire qu’il y a une infiltration de pollution dans la nappe superficielle qui alimente les puits. La conductivité électrique et la dureté totale sans être excessives présentent les valeurs les plus importantes pour les mêmes sites que sont les puits, avec des valeurs maximales respectives de 1252 μS/cm et 202 mg/L de CaCO3

Effectiveness of four different interventions against Schistosoma haematobium in a seasonal transmission setting of Côte d'Ivoire: a cluster randomized trial

BACKGROUND: Annual mass drug administration (MDA) using praziquantel is the cornerstone of schistosomiasis morbidity control, but is not sufficient to interrupt transmission. We implemented a cluster-randomized trial to compare the effectiveness of four different intervention packages to interrupt transmission of Schistosoma haematobium in a seasonal transmission setting of Cote d'Ivoire. METHODS: Sixty-four localities with a S. haematobium prevalence in school children aged 13-14 years above 4% were randomly assigned to one of four intervention arms over a 3-year period: (1) the current standard strategy consisting of annual MDA before peak of transmission; (2) annual MDA after peak of transmission; (3) biannual MDA; and (4) standard MDA combined with snail control. The primary outcome was prevalence and intensity of S. haematobium infection in children aged 9-12 years 1 year after the final intervention, using urine filtration performed by experienced microscopists. RESULTS: By study end, we observed the lowest S. haematobium prevalence in the biannual MDA, compared to the standard treatment arm (0.6% vs. 7.5%; odds ratio [OR] = 0.07, 95% confidence interval [CI] = 0.02 to 0.24). The prevalence in arms 2 and 4 was about 3.5%, which was not statistically significantly different from the standard strategy (both ORs 0.4, 95% CI = 0.1 to ~1.8). New cases of infection were still observed in all arms at study end. CONCLUSIONS: Biannual MDA was the only regimen that outperformed the standard treatment. All strategies resulted in decreased prevalence of infection, however none of them was able to interrupt transmission of S. haematobium within a 3-year period

The economic and ecological effects of water management choices in the upper Niger river: Development of decision support methods

One million people in the Inner Niger Delta make a living from arable farming, fisheries and livestock. Upstream dams (one built for electricity generation and one for irrigation) affect this downstream multifunctional use of water. Additionally, the Inner Niger Delta, which is one of the largest Ramsar sites in the world, is a hotspot of biodiversity and accommodates two of the largest known breeding colonies of large wading birds in Africa and in addition, is a vital part of the eco-regional network, supporting up to 3 to 4 million staging waterbirds, residents and migrants from all over Europe and western Asia. The hydrological and related ecological conditions in the Inner Delta largely determine the population size of these waterbird species. The major aim of the three-year study was to develop a decision-support system for river management in the Upper Niger, in which ecological and socio-economical impacts and benefits of dams and irrigation systems can be analysed in relation to different water management scenarios. The study involves various components: hydrology, arable farming, livestock, fisheries, ecology and socio-economics. An economic analysis has been conducted to determine the role of dams in the economy of the Inner Niger Delta and the Upper Niger region. By innovatively combining the above information on hydrology, ecology, fisheries, and agriculture, the study shows that building new dams is not an efficient way to increase economic growth and reduce poverty in the region. In fact, such efforts are counter-effective. Instead, development efforts should be aimed at improving the efficiency of the existing infrastructure, as well as of current economic activities in the Inner Niger Delta itself. This approach will also provide greater certainty for the essential eco-regional network functioning of the Inner Delta. © 2006 Taylor & Francis

Остеоартроз, артериальная гипертензия и ожирение: проблема коморбидности

Представлены данные современных исследований отечественных и зарубежных ученых, касающиеся распространенности сочетанной патологии − остеоартроза с артериальной гипертензией и ожирением.Наведено дані сучасних досліджень вітчизняних і зарубіжних вчених щодо поширеності поєднаної патології − остеоартрозу з артеріальною гіпертензією та ожирінням.The data of contemporary investigations of Ukrainian and foreign scientists about the prevalence of combined pathology (osteoarthrosis with arterial hypertension and obesity) are presented