New protective battle-dress impregnated against mosquito vector bites

<p>Abstract</p> <p>Background</p> <p>Mixing repellent and organophosphate (OP) insecticides to better control pyrethroid resistant mosquito vectors is a promising strategy developed for bed net impregnation. Here, we investigated the opportunity to adapt this strategy to personal protection in the form of impregnated clothes.</p> <p>Methods</p> <p>We compared standard permethrin impregnated uniforms with uniforms manually impregnated with the repellent KBR3023 alone and in combination with an organophosphate, Pirimiphos-Methyl (PM). Tests were carried out with <it>Aedes aegypti</it>, the dengue fever vector, at dusk in experimental huts.</p> <p>Results</p> <p>Results showed that the personal protection provided by repellent KBR3023-impregnated uniforms is equal to permethrin treated uniforms and that KBR3023/PM-impregnated uniforms are more protective.</p> <p>Conclusion</p> <p>The use of repellents alone or combined with OP on clothes could be promising for personal protection of military troops and travellers if residual activity of the repellents is extended and safety is verified.</p

Managing insecticide resistance in malaria vectors by combining carbamate-treated plastic wall sheeting and pyrethroid-treated bed nets

<p>Abstract</p> <p>Background</p> <p>Pyrethroid resistance is now widespread in <it>Anopheles gambiae</it>, the major vector for malaria in sub-Saharan Africa. This resistance may compromise malaria vector control strategies that are currently in use in endemic areas. In this context, a new tool for management of resistant mosquitoes based on the combination of a pyrethroid-treated bed net and carbamate-treated plastic sheeting was developed.</p> <p>Methods</p> <p>In the laboratory, the insecticidal activity and wash resistance of four carbamate-treated materials: a cotton/polyester blend, a polyvinyl chloride tarpaulin, a cotton/polyester blend covered on one side with polyurethane, and a mesh of polypropylene fibres was tested. These materials were treated with bendiocarb at 100 mg/m²and 200 mg/m²with and without a binding resin to find the best combination for field studies. Secondly, experimental hut trials were performed in southern Benin to test the efficacy of the combined use of a pyrethroid-treated bed net and the carbamate-treated material that was the most wash-resistant against wild populations of pyrethroid-resistant <it>An. gambiae </it>and <it>Culex quinquefasciatus</it>.</p> <p>Results</p> <p>Material made of polypropylene mesh (PPW) provided the best wash resistance (up to 10 washes), regardless of the insecticide dose, the type of washing, or the presence or absence of the binding resin. The experimental hut trial showed that the combination of carbamate-treated PPW and a pyrethroid-treated bed net was extremely effective in terms of mortality and inhibition of blood feeding of pyrethroid-resistant <it>An. gambiae</it>. This efficacy was found to be proportional to the total surface of the walls. This combination showed a moderate effect against wild populations of <it>Cx. quinquefasciatus</it>, which were strongly resistant to pyrethroid.</p> <p>Conclusion</p> <p>These preliminary results should be confirmed, including evaluation of entomological, parasitological, and clinical parameters. Selective pressure on resistance mechanisms within the vector population, effects on other pest insects, and the acceptability of this management strategy in the community also need to be evaluated.</p

Culicidae diversity, malaria transmission and insecticide resistance alleles in malaria vectors in Ouidah-Kpomasse-Tori district from Benin (West Africa): A pre-intervention study

<p>Abstract</p> <p>Background</p> <p>To implement an Insecticide Resistance Management (IRM) strategy through a randomized controlled trial (phase III), 28 villages were selected in southern Benin. No recent entomological data being available in these villages, entomological surveys were performed between October 2007 and May 2008, before vector control strategies implementation, to establish baseline data.</p> <p>Methods</p> <p>Mosquitoes were sampled by human landing collection (16 person-nights per village per survey per village) during 5 surveys. Mosquitoes were identified morphologically and by molecular methods. The <it>Plasmodium falciparum </it>circumsporozoïte indexes were measured by ELISA, and the entomological inoculation rates (EIRs) were calculated. Molecular detection of pyrethroid knock down resistance (<it>Kdr</it>) and of insensitive acetylcholinesterase were performed.</p> <p>Results</p> <p>44,693 mosquitoes belonging to 28 different species were caught from October 2007 to May 2008. Among mosquitoes caught, 318 were <it>An. gambiae s.s</it>., 2 were <it>An. nili</it>, 568 were <it>An. funestus s.s</it>., and one individual was <it>An. leesoni</it>. EIR was 2.05 ± 1.28 infective bites per human per 100 nights on average, of which 0.67 ± 0.60 were from <it>An. funestus </it>and 1.38 ± 0.94 infective bites were from <it>An. gambiae</it>. Important variations were noted between villages considering mosquito density and malaria transmission indicating a spatial heterogeneity in the study area. The <it>kdr </it>allelic frequency was 28.86% in <it>An. gambiae s.s</it>. on average and significantly increases from October 2007 (10.26%) to May 2008 (33.87%) in M molecular form of <it>An. gambiae s.s</it>. <it>Ace 1 </it>mutation was found in S molecular of <it>An. gambiae s.s </it>at a low frequency (< 1%).</p> <p>Conclusion</p> <p>This study updates information on mosquito diversity and malaria risk in rural villages from south Benin. It showed a high spatial heterogeneity in mosquito distribution and malaria transmission and underlines the need of further investigations of biological, ecological, and behavioral traits of malaria vectors species and forms. This study is a necessary prerequisite to cartography malaria risk and to improve vector control operations in southern Benin.</p

Frequence Des Complications De L’hypertension Arterielle Chez Les Patients Suivis En Milieu Cardiologique A Parakou En 2016

Introduction : Souvent asymptomatique, l’hypertension artérielle serévèle parfois par des événements cardiovasculaires graves. Ce travail vise àdéterminer les complications silencieuses et/ou chroniques de l’hypertensionartérielle chez les patients suivis en milieu hospitalier à Parakou. Méthodes :L’étude était transversale, analytique réalisée du 20 Mars 2016 au 20 Juillet2016, dans les services de cardiologie des hôpitaux publiques de la ville de Parakou. Etaient inclus, tousles hypertendus consentants, ayant réalisé le bilanminimum de l’Organisation Mondiale de la Santé (OMS) depuis au plus troismois. L’échantillonnage était exhaustif. Les complications silencieuses et/ouchroniques de l’HTA ont été recherchées selon les procédures standards.L’analyse des données a été faite avec le logiciel SPSS 21. Résultats : Sur les719 patients reçus en consultation, 316 (43,9%) avaient une HTA. L’âgemoyen était de 55,2 ± 11,9 ans, la sexe ratio de 0,6. L’ancienneté du diagnosticde l’HTA était inférieure à 5ans chez 61,1% des patients. L’observancethérapeutique était bonne chez 43,9% et l’HTA était mal contrôlée chez61,1%. Au moins une complication a été observée chez 70,9% des patients.Les trois premières complications chroniques étaient l’hypertrophieventriculaire gauche échographique (54,3%), la protéinurie (40,7%) et larétinopathie hypertensive (28,1%). Après régression logistique, l’anciennetéde l’HTA ≥5ans (OR=2,9 ; p=0,011) et l’inobservance thérapeutique(OR=3,1 ; p=0,002) étaient indépendamment associées à la survenue decomplication de l’HTA. Conclusion : Ces données montrent la gravité del’hypertension artérielle chez les patients et le rôle déterminant del’inobservance thérapeutique dans la survenue de ses complications. Background: High blood pressure (HBP) is often revealed bycardiovascular event, issue of undiagnosed silent complications. This studyaimed at determining the prevalence of chronic complications of HBP amongpatients followed in cardiology at Parakou in 2016. Methods: We performeda cross sectional analytic study from March 20th to July 20th, 2016 in thecardiology settings of Parakou. We did a systematic recruitment of allhypertensive patients who have done the hypertension minimum check up of World Health Organization at least three months before. HBP’s complicationswere accessed according standard guidelines. Socio-demographic data, dataon hypertension, treatment and treatment compliance were recorded for eachpatient. The software SPSS 21 was used for statistical analysis. Results:Among 719 patients admitted, 316 (43,9%) had HBP. The mean age was 55,2± 11,9 years and the sex ratio 0,6. The age of hypertension was &lt;10years in80,4%, the treatment compliance was good for 43,9% and HBP wasuncontrolled for 61,1%. At least one complication was observed in 70,9% ofpatients. The most frequents were echographic left ventricular hypertrophy(54,3%), proteinury (40,7%) and hypertensive retinopathy (28,1%). Afterlogistic regression, age of HBP≥5years(OR=2,9; p=0,011) and the therapeuticinobservance (OR=3,1; p=0,002) were independently associated with thecomplication of the HBP. Conclusion: These data show the gravity of blackpatients’ HBP which is often complicated and the crucial role therapeuticinobservance in the arisen of these complication

Education and Socio‑economic status are key factors influencing use of insecticides and malaria knowledge in rural farmers in Southern Côte d’Ivoire

Background Insecticides play a key role in rural farming; however, their over- or misuse has been linked with a negative impact on malaria vector control policies. This study was conducted amongst agricultural communities in Southern Côte d’Ivoire to identify which insecticides are used by local farmers and how it relates to the perception of farmers on malaria. Understanding the use of insecticides may help in designing awareness programme on mosquito control and pesticides management. Methods A questionnaire was administered to 1399 farming households across ten villages. Farmers were interviewed on their education, farming practices (e.g. crops cultivated, insecticides use), perception of malaria, and the different domestic strategies of mosquito control they use. Based on some pre-defined household assets, the socioeconomic status (SES) of each household was estimated. Statistical associations were calculated between different variables, showing significant risk factors. Results The educational level of farmers was significantly associated with their SES (p < 0.0001). Most of the householders (88.82%) identified mosquitoes as the principal cause of malaria, with good knowledge of malaria resulting as positively related to high educational level (OR = 2.04; 95%CI: 1.35, 3.10). The use of indoor chemical compounds was strongly associated to the SES of the households, their education level, their use of ITNs and insecticide in agricultural (p < 0.0001). Indoor application of pyrethroid insecticides was found to be widespread among farmers as well as the use of such insecticide for crops protection. Conclusion Our study shows that the education level remains the key factor influencing the use of insecticides by farmers and their awareness of malaria control. We suggest that better communication tailored to education level and including SES, controlled availability and access to chemical products, should be considered when designing campaigns on use of pesticides and vector borne disease control for local communities

Clinical features, proximate causes, and consequences of active convulsive epilepsy in Africa

Purpose: Epilepsy is common in sub-Saharan Africa (SSA), but the clinical features and consequences are poorly characterized. Most studies are hospital-based, and few studies have compared different ecological sites in SSA. We described active convulsive epilepsy (ACE) identified in cross-sectional community-based surveys in SSA, to understand the proximate causes, features, and consequences. Methods: We performed a detailed clinical and neurophysiologic description of ACE cases identified from a community survey of 584,586 people using medical history, neurologic examination, and electroencephalography (EEG) data from five sites in Africa: South Africa; Tanzania; Uganda; Kenya; and Ghana. The cases were examined by clinicians to discover risk factors, clinical features, and consequences of epilepsy. We used logistic regression to determine the epilepsy factors associated with medical comorbidities. Key Findings: Half (51%) of the 2,170 people with ACE were children and 69% of seizures began in childhood. Focal features (EEG, seizure types, and neurologic deficits) were present in 58% of ACE cases, and these varied significantly with site. Status epilepticus occurred in 25% of people with ACE. Only 36% received antiepileptic drugs (phenobarbital was the most common drug [95%]), and the proportion varied significantly with the site. Proximate causes of ACE were adverse perinatal events (11%) for onset of seizures before 18 years; and acute encephalopathy (10%) and head injury prior to seizure onset (3%). Important comorbidities were malnutrition (15%), cognitive impairment (23%), and neurologic deficits (15%). The consequences of ACE were burns (16%), head injuries (postseizure) (1%), lack of education (43%), and being unmarried (67%) or unemployed (57%) in adults, all significantly more common than in those without epilepsy. Significance: There were significant differences in the comorbidities across sites. Focal features are common in ACE, suggesting identifiable and preventable causes. Malnutrition and cognitive and neurologic deficits are common in people with ACE and should be integrated into the management of epilepsy in this region. Consequences of epilepsy such as burns, lack of education, poor marriage prospects, and unemployment need to be addressed

Resistance to pirimiphos-methyl in West African Anopheles is spreading via duplication and introgression of the Ace1 locus

Vector population control using insecticides is a key element of current strategies to prevent malaria transmission in Africa. The introduction of effective insecticides, such as the organophosphate pirimiphos-methyl, is essential to overcome the recurrent emergence of resistance driven by the highly diverse Anopheles genomes. Here, we use a population genomic approach to investigate the basis of pirimiphos-methyl resistance in the major malaria vectors Anopheles gambiae and A. coluzzii. A combination of copy number variation and a single non-synonymous substitution in the acetylcholinesterase gene, Ace1, provides the key resistance diagnostic in an A. coluzzii population from Côte d’Ivoire that we used for sequence-based association mapping, with replication in other West African populations. The Ace1 substitution and duplications occur on a unique resistance haplotype that evolved in A. gambiae and introgressed into A. coluzzii, and is now common in West Africa primarily due to selection imposed by other organophosphate or carbamate insecticides. Our findings highlight the predictive value of this complex resistance haplotype for phenotypic resistance and clarify its evolutionary history, providing tools to for molecular surveillance of the current and future effectiveness of pirimiphos-methyl based interventions

Efficacy of an insecticide paint against malaria vectors and nuisance in West Africa - Part 2: Field evaluation

<p>Abstract</p> <p>Background</p> <p>Widespread resistance of the main malaria vector <it>Anopheles gambiae </it>to pyrethroids reported in many African countries and operational drawbacks to current IRS methods suggest the convenience of exploring new products and approaches for vector control. Insecticide paint Inesfly 5A IGR™, containing two organophosphates (OPs), chlorpyrifos and diazinon, and one insect growth regulator (IGR), pyriproxyfen, was tested in Benin, West Africa, for 12 months.</p> <p>Methods</p> <p>Field trials were conducted in six experimental huts that were randomly allocated to one or two layers of insecticide at 1 Kg/6 m²or control. Evaluations included: (i) early mosquito collection, (ii) mosquito release experiments, (iii) residual efficacy tests and (iv) distance tests. Early mosquito collections were performed on local populations of pyrethroid-resistant <it>An. gambiae </it>and <it>Culex quinquefasciatus</it>. As per WHOPES phase II procedures, four entomological criteria were evaluated: deterrence, excito-repellence, blood-feeding inhibition and mortality. Mosquito release experiments were done using local malaria-free <it>An. gambiae </it>females reared at the CREC insectarium. Residual efficacy tests and distance tests were performed using reference susceptible strains of <it>An. gambiae </it>and <it>Cx. quinquefasciatus</it>.</p> <p>Results</p> <p>Six months after treatment, mortality rates were still 90-100% against pyrethroid-resistant mosquito populations in experimental huts. At nine months, mortality rates in huts treated with two layers was still about 90-93% against <it>An. gambiae </it>and 55% against <it>Cx. quinquefasciatus</it>. Malaria-free local mosquito release experiments yielded a 90% blood-feeding inhibition in the absence of a physical barrier. A long-term residual efficacy of 12 months was observed by WHO-bioassays in huts treated with two layers (60-80%). Mortality after an overnight exposition at distances of 1 meter was 96-100% for up to 12 months.</p> <p>Conclusion</p> <p>The encouraging results obtained on the insecticide paint Inesfly 5A IGR™ in terms of mortality, be it in direct contact or at a distance, and its new operational approach could constitute an additional option in malaria control efforts in areas of pyrethroid resistance. Phase III studies will be performed to assess the product's epidemiological impact and sociological acceptance.</p

Appropriateness of clinical severity classification of new WHO childhood pneumonia guidance : a multi-hospital, retrospective, cohort study

Background: Management of pneumonia in many low-income and middle-income countries is based on WHO guidelines that classify children according to clinical signs that define thresholds of risk. We aimed to establish whether some children categorised as eligible for outpatient treatment might have a risk of death warranting their treatment in hospital. Methods: We did a retrospective cohort study of children aged 2–59 months admitted to one of 14 hospitals in Kenya with pneumonia between March 1, 2014, and Feb 29, 2016, before revised WHO pneumonia guidelines were adopted in the country. We modelled associations with inpatient mortality using logistic regression and calculated absolute risks of mortality for presenting clinical features among children who would, as part of revised WHO pneumonia guidelines, be eligible for outpatient treatment (non-severe pneumonia). Findings: We assessed 16 162 children who were admitted to hospital in this period. 832 (5%) of 16 031 children died. Among groups defined according to new WHO guidelines, 321 (3%) of 11 788 patients with non-severe pneumonia died compared with 488 (14%) of 3434 patients with severe pneumonia. Three characteristics were strongly associated with death of children retrospectively classified as having non-severe pneumonia: severe pallor (adjusted risk ratio 5·9, 95% CI 5·1–6·8), mild to moderate pallor (3·4, 3·0–3·8), and weight-for-age Z score (WAZ) less than −3 SD (3·8, 3·4–4·3). Additional factors that were independently associated with death were: WAZ less than −2 to −3 SD, age younger than 12 months, lower chest wall indrawing, respiratory rate of 70 breaths per min or more, female sex, admission to hospital in a malaria endemic region, moderate dehydration, and an axillary temperature of 39°C or more. Interpretation: In settings of high mortality, WAZ less than −3 SD or any degree of pallor among children with non-severe pneumonia was associated with a clinically important risk of death. Our data suggest that admission to hospital should not be denied to children with these signs and we urge clinicians to consider these risk factors in addition to WHO criteria in their decision making