120 research outputs found
First malaria infections in a cohort of infants in Benin: biological, environmental and genetic determinants. Description of the study site, population methods and preliminary results
Objectives: Malaria infection of the placenta during pregnancy was found to be associated with infant susceptibility to malaria. Other factors such as the intensity of malaria transmission and the nutritional status of the child might also play a role, which has not been adequately taken into account in previous studies. The aim of this study was to assess precisely the parts played by environmental, nutritional and biological determinants in first malaria infections, with a special interest in the role of placental infection. The objective of this paper is not to present final results but to outline the rationale of the study, to describe the methods used and to report baseline data. Design: A cohort of infants followed with a parasitological (symptomatic and asymptomatic parasitaemia) and nutritional follow-up from birth to 18 months. Ecological, entomological and behavioural data were collected along the duration of the study. Setting: A rural area in Benin with two seasonal peaks in malaria transmission. Participants: 656 infants of women willing to participate in the study, giving birth in one of the three maternity clinics and living in one of the nine villages of the study area. Primary Outcome Measures: The time and frequency of first malaria parasitaemias in infants, according to Plasmodium falciparum infection of the placenta. Results: 11% of mothers had a malaria-infected placenta at delivery. Mosquito catches made every 6 weeks in the area showed an average annual P falciparum entomological inoculation rate of 15.5, with important time and space variations depending on villages. Similarly, the distribution of rainfalls, maximal during the two rainy seasons, was heterogeneous over the area. Conclusions: Considering the multidisciplinary approach of all factors potentially influencing the malaria status of newborn babies, this study should bring evidence on the implication of placental malaria in the occurrence of first malaria infections in infants
Are communities ready to address the issue of poor food safety and nutritional quality in urban Senegal?
Background and objectives: In Senegal, increased prevalence of overweight/obesity and diet-related non-communicable diseases is of paramount concern, urging the transformation of food systems to deliver more nutritious and safe foods. Community involvement is recognised as an important factor in the success and sustainability of efforts to promote healthy eating and prevent overweight/obesity. Therefore, this study aimed to assess communities' readiness to address the issue of poor food safety and nutritional quality of foods available in their food environments (i.e., places where consumers acquire or consume foods) in urban Senegal. Methods: The Community Readiness Model (CRM), consisting of 36 open questions that revolves around five dimensions of readiness (community knowledge of efforts, leadership, community climate, knowledge of the issue and resources) was used. Community leaders and actors who play a key role within the food environment were individually interviewed in two neighbourhoods of Guediawaye (n=9) and Dakar (n=10). Interviews were scored with a maximum of 9 points per dimension (1= no awareness, 9= high level of community ownership) and thematic analysis was conducted on key informants' recommendations to ensure nutritious and safe food systems. Results: Both communities reached the stage of 'vague awareness' of the issue, with a mean score of 3.00 ± 1.94 in Guediawaye and 3.11 ± 1.58 in Dakar. Both communities scored highest for 'knowledge of the issue' (6.00 ± 2.44 in Guediawaye; 5.69 ± 2.08 in Dakar), while the lowest scores were found for 'community knowledge of efforts' (1.46 ± 0.81 in Guediawaye; 1.86 ± 2.30 in Dakar). Leaders' concern and prioritisation of this issue was perceived as inexistent in both neighbourhoods, contrasting with high levels of community concern. Proposed solutions included: raising community awareness, improving sanitation infrastructure locally and nationally, and increasing government involvement. Conclusions: While several key informants recognised the lack of nutritious and safe food is a concern, they also highlighted other priority issues, such as lack of financial security, infrastructure and/or food insecurity/hunger within their communities. Encouraging community readiness through public awareness campaigns and increasing government engagement is needed before interventions to promote safe and nutritious food in urban Senegal can be introduced
Best practice coral restoration for the Great Barrier Reef
As the Great Barrier Reef (GBR) continues to degrade through repeated mass bleaching events, crown-of-thorns starfish and major disease outbreaks, and the impacts of intense cyclones, pressure is growing for direct intervention to assist the recovery of reef-building corals. Decreasing coral cover on the GBR and other Australian reefs has been recognised as a serious problem relatively recently in Australia but follows a global trend, with many overseas reefs now highly degraded. Various types of coral restoration, rehabilitation and assisted recovery projects have been trialled overseas for decades and it makes sense to look at what has and hasn’t worked overseas to determine a range of options that may suit GBR conditions. Some direct interventions to assist coral recovery have been trialled in Australia such as transplanting corals, algae removal to promote coral recovery and larval enhancement promoting direct coral recruitment. In addition, after physical damage from cyclones, ship strikes or dragged anchors, local dive operators and dive clubs (permitted or unpermitted) often attempt to assist the recovery of corals by tipping over flipped tabular corals and reattaching broken branching corals or sea fans. These latter assisted recovery techniques are rarely underpinned by scientific data on coral recovery. A lack of best practice guidelines for these actions limits the chance of success and increases the health and safety risks of these activities
First detection of critically endangered scalloped hammerhead sharks (Sphyrna lewini) in Guam, Micronesia, in five decades using environmental DNA
Among the hammerhead sharks, scalloped hammerheads (Sphyrna lewini) have undergone the steepest population declines worldwide. Due to their high susceptibility to exploitation, the species is now classified as ‘critically endangered’, the most threatened category listed by the International Union for Conservation of Nature. There is an urgent need for data on the distribution of S. lewini to inform the design and implementation of effective conservation management strategies, and mitigate the risk of global extinction. Environmental DNA (eDNA) is emerging as a powerful method to monitor the geographic distribution, population trends, and habitat usage of rare and endangered species. In comparison to traditional survey methods, eDNA methods offer lower cost, higher detection rates, and are non-invasive. At present, there is no targeted eDNA assay for the detection of S. lewini and existing methods to assess their distribution are either fisheries-dependent, leading to bias, or costly and laborious, leading to impracticality in regions of low or unknown abundance. Here we present an optimised workflow for the detection of S. lewini presence using eDNA methods, and apply these to successfully detect scalloped hammerhead sharks in Guam, of the western Pacific Ocean, where their presence has not been scientifically reported since the 1970s. The detection of S. lewini by eDNA survey methods was achieved from a single-day sampling effort, demonstrating the efficacy of the technique and workflow. If implemented, the eDNA survey methods developed here will enable the rapid generation of information on the distribution of scalloped hammerhead sharks in the western Pacific, and likely globally, and assist in the accurate placement of no-take reserves to best enable the species’ recovery
Infections in Infants during the First 12 Months of Life: Role of Placental Malaria and Environmental Factors
Background: The association between placental malaria (PM) and first peripheral parasitaemias in early infancy was assessed in Tori Bossito, a rural area of Benin with a careful attention on transmission factors at an individual level. Methodology: Statistical analysis was performed on 550 infants followed weekly from birth to 12 months. Malaria transmission was assessed by anopheles human landing catches every 6 weeks in 36 sampling houses and season defined by rainfall. Each child was located by GPS and assigned to the closest anopheles sampling house. Data were analysed by survival Cox models, stratified on the possession of insecticide-treated mosquito nets (ITNs) at enrolment. Principal Findings: Among infants sleeping in a house with an ITN, PM was found to be highly associated to first malaria infections, after adjusting on season, number of anopheles, antenatal care (ANC) visits and maternal severe anaemia. Infants born from a malaria infected placenta had a 2.13 fold increased risk to present a first malaria infection than those born from a non infected placenta ([1.24-3.67], p<0.01) when sleeping in a house with an ITN. The risk to present a first malaria infection was increased by 3.2 to 6.5, according to the level of anopheles exposure (moderate or high levels, compared to the absence of anopheles). Conclusions: First malaria infections in early childhood can be attributed simultaneously to both PM and high levels of exposure to infected anopheles. Protective measures as Intermittent Preventive Treatment during pregnancy (IPTp) and ITNs, targeted on both mothers and infants should be reinforced, as well as the research on new drugs and insecticides. In parallel, investigations on placental malaria have to be strengthened to better understand the mechanisms involved, and thus to protect adequately the infants high risk group
Association of IL-4 and IL-10 maternal haplotypes with immune responses to P. falciparum in mothers and newborns
Abstract Background: Particular cytokine gene polymorphisms are involved in the regulation of the antibody production. The consequences of already described IL-4, IL-10 and IL-13 gene polymorphisms on biological parameters and antibody levels were investigated among 576 mothers at delivery and their newborns in the context of P. falciparum placental malaria infection. Methods: The study took place in the semi-rural area of Tori-Bossito, in south-west Benin, where malaria is meso-endemic. Six biallelic polymorphisms were determined by quantitative PCR using TaqMan W Pre-Designed SNP Genotyping Assays, in IL-4 (rs2243250, rs2070874), IL-10 (rs1800896, rs1800871, rs1800872) and IL-13 (rs1800925) genes. Antibody responses directed to P. falciparum MSP-1, MSP-2, MSP-3, GLURP-R0, GLURP-R2 and AMA-1 recombinant proteins were determined by ELISA. Results: The maternal IL-4 −590 *T/IL-4 +33 *T haplotype (one or two copies) was associated with favorable maternal condition at delivery (high haemoglobin levels, absence of placental parasites) and one of its component, the IL-4 −590 TT genotype, was related to low IgG levels to MSP-1, MSP-2/3D7 and MSP-2/FC27. Inversely, the maternal IL-10 −1082 AA was positively associated with P. falciparum placenta infection at delivery. As a consequence, the IL-10 −819 *T allele (in CT and TT genotypes) as well as the IL-10 −1082 *A/IL-10 −819 *T/IL-10 −592 *A haplotype (one or two copies) in which it is included, were related to an increased risk for anaemia in newborns. The maternal IL-10 −1082 AA genotype was related to high IgG levels to MSP-2/3D7 and AMA-1 in mothers and newborns, respectively. The IL-13 gene polymorphism was only involved in the newborn's antibody response to AMA-1. Conclusion: These data revealed that IL-4 and IL-10 maternal gene polymorphisms are likely to play a role in the regulation of biological parameters in pregnant women at delivery (anaemia, P. falciparum placenta infection) and in newborns (anaemia). Moreover, IL-4, IL-10 and IL-13 maternal gene polymorphisms were related to IgG responses to MSP-1, MSP-2/3D7 and MSP-2/FC27 in mothers as well as to AMA-1 in newborns
Relation between Plasmodium falciparum asymptomatic infection and malaria attacks in a cohort of Senegalese children
© 2008 Le Port et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Modeling the Influence of Local Environmental Factors on Malaria Transmission in Benin and Its Implications for Cohort Study
Malaria remains endemic in tropical areas, especially in Africa. For the evaluation of new tools and to further our understanding of host-parasite interactions, knowing the environmental risk of transmission—even at a very local scale—is essential. The aim of this study was to assess how malaria transmission is influenced and can be predicted by local climatic and environmental factors
Association of IL-4 and IL-10 maternal haplotypes with immune responses to P. falciparum in mothers and newborns
Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)
From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions
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