75 research outputs found
Relapse and post-discharge body composition of children treated for acute malnutrition using a simplified, combined protocol: A nested cohort from the ComPAS RCT
INTRODUCTION: Severe and moderate acute malnutrition (SAM and MAM) affect more than 50 million children worldwide yet 80% of these children do not access care. The Combined Protocol for Acute Malnutrition Study (ComPAS) trial assessed the effectiveness of a simplified, combined SAM/MAM protocol for children aged 6-59 months and found non-inferior recovery compared to standard care. To further inform policy, this study assessed post-discharge outcomes of children treated with this novel protocol in Kenya. METHODS: Six 'combined' protocol clinics treated SAM and MAM children using an optimised mid-upper arm circumference (MUAC)-based dose of ready-to-use therapeutic food (RUTF). Six 'standard care' clinics treated SAM with weight-based RUTF rations; MAM with ready-to-use supplementary food (RUSF). Four months post-discharge, we assessed anthropometry, recent history of illness, and body composition by bioelectrical impedance analysis. Data was analysed using multivariable linear regression, adjusted for age, sex and allowing for clustering by clinic. RESULTS: We sampled 850 children (median age 18 months, IQR 15-23); 44% of the original trial sample in Kenya. Children treated with the combined protocol had similar anthropometry, fat-free mass, fat mass, skinfold thickness z-scores, and frequency of common illnesses 4 months post-discharge compared the standard protocol. Mean subscapular skinfold z-scores were close to the global norm (standard care: 0.24; combined 0.27). There was no significant difference in odds of relapse between protocols (SAM, 3% vs 3%, OR = 1.0 p = 0.75; MAM, 10% vs 12%, OR = 0.90 p = 0.34). CONCLUSIONS: Despite the lower dosage of RUTF for most SAM children in the combined protocol, their anthropometry and relapse rates at 4 months post-discharge were similar to standard care. MAM children treated with RUTF had similar body composition to those treated with RUSF and neither group exhibited excess adiposity. These results add further evidence that a combined protocol is as effective as standard care with no evidence of adverse effects post-discharge. A simplified, combined approach could treat more children, stretch existing resources further, and contribute to achieving Sustainable Development Goal Two
Serological Conservation of Parasite-Infected Erythrocytes Predicts Plasmodium falciparum Erythrocyte Membrane Protein 1 Gene Expression but Not Severity of Childhood Malaria.
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), expressed on P. falciparum-infected erythrocytes, is a major family of clonally variant targets of naturally acquired immunity to malaria. Previous studies have demonstrated that in areas where malaria is endemic, antibodies to infected erythrocytes from children with severe malaria tend to be more seroprevalent than antibodies to infected erythrocytes from children with nonsevere malaria. These data have led to a working hypothesis that PfEMP1 variants associated with parasite virulence are relatively conserved in structure. However, the longevity of such serologically conserved variants in the parasite population is unknown. Here, using infected erythrocytes from recently sampled clinical P. falciparum samples, we measured serological conservation using pools of antibodies in sera that had been sampled 10 to 12 years earlier. The serological conservation of infected erythrocytes strongly correlated with the expression of specific PfEMP1 subsets previously found to be associated with severe malaria. However, we found no association between serological conservation per se and disease severity within these data. This contrasts with the simple hypothesis that P. falciparum isolates with a serologically conserved group of PfEMP1 variants cause severe malaria. The data are instead consistent with periodic turnover of the immunodominant epitopes of PfEMP1 associated with severe malaria.Wellcome Trust (084535, 077092, 084538, and 098635)This is the final version of the article. It first appeared from the American Society for Microbiology via http://dx.doi.org/10.1128/IAI.00772-1
Small-scale agricultural grassland management can affect soil fungal community structure as much as continental scale geographic patterns
A European transect was established, ranging from Sweden to the Azores, to determine the relative influence of geographic factors and agricultural small-scale management on the grassland soil microbiome. Within each of five countries (factor âCountryâ), which maximized a range of geographic factors, two differing growth condition regions (factor âGCRâ) were selected: a favorable region with conditions allowing for high plant biomass production and a contrasting less favorable region with a markedly lower potential. Within each region, grasslands of contrasting management intensities (factor âMIâ) were defined: intensive and extensive, from which soil samples were collected. Across the transect, âMIâ was a strong differentiator of fungal community structure, having a comparable effect to continental scale geographic factors (âCountryâ). âMIâ was also a highly significant driver of bacterial community structure, but âCountryâ was clearly the stronger driver. For both, âGCRâ was the weakest driver. Also at the regional level, strong effects of MI occurred on various measures of the soil microbiome (i.e. OTU richness, management-associated indicator OTUs), though the effects were largely regional-specific. Our results illustrate the decisive influence of grassland MI on soil microbial community structure, over both regional and continental scales, and, thus, highlight the importance of preserving rare extensive grasslands
Agro-ecology, resource endowment and indigenous knowledge interactions modulate soil fertility in mixed farming systems in central and western Ethiopia
Open Access Article; Published online: 14 Feb 2021Siteâspecific soil fertility management requires a fundamental understanding of factors that modulate soil fertility variability in the local context. To verify this assumption, this study hypothesized that soil fertility variability across two regions in Central and Western Ethiopia is determined by interârelated effects of agroâecological zones and farmersâ resource endowment (âwealthyâ versus âpoorâ farmers). Midâinfrared spectroscopy coupled to partial least squares regression (midDRIFTSâPLSR) and wetâlaboratory analyses were used to assess the soil fertility (soil pH, total soil carbon [TC] and nitrogen [TN], plantâavailable phosphorous [Pav] and potassium [Kav]) across four agroâecological zones: âHighâDegaâ (HD), âDegaâ (D), âWeinaâDegaâ (WD) and âKolaâ (K). MidDRIFTS peak area analysis of spectral frequencies (2,930 [aliphatic CâH], 1,620 [aromatic C = C], 1,159 [CâO polyâalcoholic and ether groups] cmâ1) was applied to characterize soil organic carbon (SOC) quality and to calculate the SOC stability index (1,620:2,930). Higher TC in HD, as well as higher TN and Kav contents in K were found in fields of wealthy compared with poor farmers. Resource endowment dependent soil fertility management options revealed SOC of higher quality in wealthy compared with poor farms in D. Agroâecological zones distinctions contributed to these soil fertility differences. Farmers distinguished visually fertile and less fertile fields based on soil colour. Higher pH in K and WD as well as Pav in K and HD were found in fertile (brown/black) than less fertile (red) soils. To conclude, tailorâmade soil fertility management in the local context must consider agroâecological zones and resource endowment interactions along with farmersâ indigenous knowledge
HIV acquisition prior to entry into formal sex work: inference from next-generation viral sequencing.
OBJECTIVE: To infer the timing of HIV acquisition in relation to self-reported events in the sexual life course of adolescent girls and young women (AGYW) who self-identify as female sex workers (FSW) in Mombasa, Kenya. DESIGN: Next-generation viral sequencing of samples of AGYW living with HIV in the Transitions study, a cross-sectional bio-behavioural survey of AGYW aged 14-24âyears in Mombasa, Kenya. METHOD: Dried blood spot specimens were collected from study participants ( n â=â37, all FSW). A portion of the HIV pol gene was sequenced using an in-house next-generation sequencing assay for HIV drug resistance mutation genotyping. Estimated time since infection (ETI) was inferred using the HIV EVO web-based tool ( https://hiv.biozentrum.unibas.ch/ETI/ ), and data on self-reported events were obtained from the survey. RESULTS: The median ETI among FSW was 3.4 (interquartile rangeâ=â1.7, 6.3) years, with a median ETI of 1.5âyears prior to entry into formal sex work. We estimated that 74.1% (95% confidence interval = 53.7-88.9%) of participants living with HIV and who self-identified as FSW likely acquired HIV prior to self-identification as a sex worker. CONCLUSIONS: Findings suggest a large fraction of prevalent HIV infection among AGYW engaged in sex work stems from acquisition prior to entry into formal sex work. Current HIV prevention programs tailored for sex workers may miss key opportunities for HIV prevention as they are designed to reach women after entry into formal sex work, signaling a need for tailored programs to reach high-risk AGYW earlier on in their sexual life course
Community-Led Total Sanitation: A Mixed-Methods Systematic Review of Evidence and Its Quality
Background: Community-led total sanitation (CLTS) is a widely applied rural behavior change approach for ending open defecation. However, evidence of its impact is unclear.
Objectives: We conducted a systematic review of journal-published and gray literature to a) assess evidence quality, b) summarize CLTS impacts, and c) identify factors affecting implementation and effectiveness.
Methods: Eligible studies were systematically screened and selected for analysis from searches of seven databases and 16 websites. We developed a framework to appraise literature quality. We qualitatively analyzed factors enabling or constraining CLTS, and summarized results from quantitative evaluations.
Discussion: We included 200 studies (14 quantitative evaluations, 29 qualitative studies, and 157 case studies). Journal-published literature was generally of higher quality than gray literature. Fourteen quantitative evaluations reported decreases in open defecation, but did not corroborate the widespread claims of open defecationâfree (ODF) villages found in case studies. Over one-fourth of the literature overstated conclusions, attributing outcomes and impacts to interventions without an appropriate study design. We identified 43 implementation- and community-related factors reportedly affecting CLTS. This analysis revealed the importance of adaptability, structured posttriggering activities, appropriate community selection, and further research on combining and sequencing CLTS with other interventions.
Conclusions: The evidence base on CLTS effectiveness available to practitioners, policy makers, and program managers to inform their actions is weak. Our results highlight the need for more rigorous research on CLTS impacts as well as applied research initiatives that bring researchers and practitioners together to address implementation challenges to improve rural sanitation efforts
Effectiveness of a LED flashlight technique in reducing livestock depredation by lions (Panthera leo) around Nairobi National Park, Kenya
Conservation Biolog
Use of Maerua Decumbens as a Natural Coagulant for Water Purification in the Dry Lands of Kenya
ABSTRACT: Indigenous management and utilization of naturally occurring tree species and shrubs/lianas is not a new culture worldwide. Various communities in the world use their indigenous tree /shrub / liana species to meet their needs for food (human and livestock), shelter and medicine among other diverse wood and non-wood forest products. Introduction of new exotic species has eroded the importance of some of these important indigenous plant species to great extends. It is however, important to consider that while these exotic species have multiple uses, most of them are not well adapted to our arid and semi-arid regions hence the need to promote the management and sustainable use of the indigenous species. Maerua decumbens is a shrub or woody herb species in the Capparaceae family and grows to a height of 0.5 to 3m with a large swollen root. It mostly occurs naturally in the arid and semiarid areas in Kenya and is used traditionally by rural communities for medicinal and water purification purposes. Members of the Mearua species are indicated as poisonous and probably a health risk and yet some of the communities chew the roots of Mearua decumbens against thirst and also use them for purifying water (Beenje H.1994). The study was done to enhance the use of Maerua decumbens as a natural coagulant for water purification by determining whether the plant used for water purification in Mutha in Kitui County is toxic or not. A reconnaissance survey was done to confirm its use for water purification and toxicity tests were done to determine the safety of the plant for human utilization as a natural coagulant for water purification. The results of the study revealed that M.decumbens is completely safe for human consumption and does not have any heavy metals that pose a risk to human health
Controlled Human Malaria Infection in Semi-Immune Kenyan Adults (CHMI-SIKA): a study protocol to investigate in vivo Plasmodium falciparum malaria parasite growth in the context of pre-existing immunity [version 2; peer review: 2 approved]
Malaria remains a major public health burden despite approval for implementation of a partially effective pre-erythrocytic malaria vaccine. There is an urgent need to accelerate development of a more effective multi-stage vaccine. Adults in malaria endemic areas may have substantial immunity provided by responses to the blood stages of malaria parasites, but field trials conducted on several blood-stage vaccines have not shown high levels of efficacy. We will use the controlled human malaria infection (CHMI) models with malaria-exposed volunteers to identify correlations between immune responses and parasite growth rates in vivo. Immune responses more strongly associated with control of parasite growth should be prioritized to accelerate malaria vaccine development. We aim to recruit up to 200 healthy adult volunteers from areas of differing malaria transmission in Kenya, and after confirming their health status through clinical examination and routine haematology and biochemistry, we will comprehensively characterize immunity to malaria using >100 blood-stage antigens. We will administer 3,200 aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (PfSPZ Challenge) by direct venous inoculation. Serial quantitative polymerase chain reaction to measure parasite growth rate in vivo will be undertaken. Clinical and laboratory monitoring will be undertaken to ensure volunteer safety. In addition, we will also explore the perceptions and experiences of volunteers and other stakeholders in participating in a malaria volunteer infection study. Serum, plasma, peripheral blood mononuclear cells and whole blood will be stored to allow a comprehensive assessment of adaptive and innate host immunity. We will use CHMI in semi-immune adult volunteers to relate parasite growth outcomes with antibody responses and other markers of host immunity. / Registration: ClinicalTrials.gov identifier NCT02739763
The evolving SARS-CoV-2 epidemic in Africa: insights from rapidly expanding genomic surveillance
Investment in SARS-CoV-2 sequencing in Africa over the past year has led to a major increase in the number of sequences generated, now exceeding 100,000 genomes, used to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence domestically, and highlight that local sequencing enables faster turnaround time and more regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and shed light on the distinct dispersal dynamics of Variants of Concern, particularly Alpha, Beta, Delta, and Omicron, on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve, while the continent faces many emerging and re-emerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
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