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9415 ressources

  • Article libreArticleEn anglais

    A mixed methods evaluation of the effectiveness of an oral health training program for disability care workers in Burkina Faso

    Ave Põld, Dan Filwendé Kientega, Jocelyne Valérie Garé, Stefan Listl

    BackgroundWhile efforts to improve the oral health of vulnerable populations have received little attention in general, the situation of children with disabilities in low- income countries (LICs) remains especially challenging. The present study evaluated the effectiveness of an oral health training provided to disability care workers in Ouagadougou, Burkina Faso thereby contributing to closing the knowledge gap in disability research in relation to oral health in LICs.MethodsThis was a single-arm pre-post study following an embedded mixed methods design using the New World Kirkpatrick training effectiveness evaluation model. For the purposes of this study, three levels of the Kirkpatrick (KP) evaluation were considered: reaction, learning and behaviour.ResultsA total of 44 care workers from 6 disability centres participated in the study. Care worker post-training scores (Md = 17) were significantly higher compared to pre-training scores (Md = 13) [Wilcoxon signed-ranks test: Z= -5.53, p < .001, r = .59.] The median value for care worker confidence in applying training material in their everyday job was 7 out of 10 points (IQR = 3). At the 1-month training follow-up, 3 centres had implemented daily toothbrushing for people with disabilities.ConclusionThese findings suggest that tailored training led to an increase in care worker confidence and motivation to implement oral health activities, in knowledge about oral health and a partial implementation uptake of daily toothbrushing in disability centres. Further long-term evaluations with dental care provision in rural and urban settings are needed to lower the high oral disease burden of people with disabilities in Burkina Faso.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12903-023-03837-8.

    PédiatrieSanté publiqueLicence : Open Access http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/publicdomain/zero/1.0/ This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as
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  • Article libreArticleEn anglais

    A mixed methods protocol to evaluate the effect and cost-effectiveness of an Integrated electronic Diagnosis Approach (IeDA) for the management of childhood illnesses at primary health facilities in Burkina Faso

    Karl Blanchet, James J. Lewis, Francisco Pozo-Martin, Arsene Satouro, Serge Somda, Patrick Ilboudo, Sophie Sarrassat, Simon Cousens

    BackgroundBurkina Faso introduced the Integrated Management of Childhood Illnesses (IMCI) strategy in 2003. However, an evaluation conducted in 2013 found that only 28 % of children were assessed for three danger signs as recommended by IMCI, and only 15 % of children were correctly classified. About 30 % of children were correctly prescribed with an antibiotic for suspected pneumonia or oral rehydration salts (ORS) for diarrhoea, and 40 % were correctly referred. Recent advances in information and communication technologies (ICT) and use of electronic clinical protocols hold the potential to transform healthcare delivery in low-income countries. However, no evidence is available on the effect of ICT on adherence to IMCI. This paper describes the research protocol of a mixed methods study that aims to measure the effect of the Integrated electronic Diagnosis Approach innovation (an electronic IMCI protocol provided to nurses) in two regions of Burkina Faso.Methods/designThe study combines a stepped-wedge trial, a realistic evaluation and an economic study in order to capture the effect of the innovation after its introduction on the level of adherence, cost and acceptability.DiscussionThe main challenge is to interconnect the three substudies. In integrating outcome, process and cost data, we focus on three key questions: (i) How does the effectiveness and the cost of the intervention vary by type of health worker and type of health centre? (ii) What is the impact of changes in the content, coverage and quality of the IeDA intervention on adherence and cost-effectiveness? (iii) What mechanisms of change (including costs) might explain the relationship between the IeDA intervention and adherence?Trial registrationClinicaltrials.gov, NCT02341469.

    Microbiologie (bactériologie, virologie)PharmacologiePédiatrieLicence : Open Access http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/publicdomain/zero/1.0/ This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (), which permits unrestricted use, distribution, and reproduction in any medium, provid
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  • Article libreArticleEn anglais

    A mixed-methods approach to understanding pharmacists’ experiences with the CANRISK diabetes risk questionnaire and user guide

    Josephine Ta, Ying Jiang, Sebastian Srugo, Howard Morrison, Margaret de Groh

    AbstractIntroduction:The Canadian Diabetes Risk Questionnaire (CANRISK) is a validated tool for diabetes risk screening, but the extent of its uptake and implementation by Canadian pharmacists has not been assessed. We aimed to describe the current use of the CANRISK tool and user guide among pharmacists, identify facilitators and barriers, and provide solutions to improve uptake. Methods:We used a mixed-methods approach comprising an initial quantitative online survey followed by qualitative interviews with pharmacists to allow for a deeper understanding of their experiences. Descriptive statistics were used to analyze the survey data and thematic analysis was used to analyze the interview data. Results:We found that 89% of pharmacists surveyed provided diabetes counselling on a daily or weekly basis, but more than half (55%) were not aware of CANRISK and its user guide. Of those who were aware, 60% indicated that they rarely or never used CANRISK. Five overarching themes were identified in the qualitative component. The facilitators to CANRISK uptake included pharmacist’s interest, diabetes clinic days/awareness campaigns, and patient-provider relationship. However, there are barriers to its implementation, including time constraints, competing priorities, financial pressures, staff shortages, and limited understanding of the tool’s usefulness. Conclusion:This paper found that CANRISK use was limited, and that support is needed to address the barriers for the successful implementation of CANRISK in pharmacies.

    Biostatistiques et épidémiologieMédecine interne (cardiologie, endocrinologie, néphrologie…)Santé publiqueLicence : This work is licensed under a Creative Commons Attribution 4.0 International License
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  • Article libreArticleEn anglais

    A model-informed target product profile for population modification gene drives for malaria control

    As reductions in malaria transmission in sub-Saharan Africa stagnate, gene drive-modified mosquitoes represent one of the most promising novel tools for continued disease control. In order to advance from the laboratory to the field, gene drives will be assessed against target product profiles, planning tools that list minimum criteria products should satisfy as they progress through the development pipeline. We used an eco-epidemiological model to investigate parameter values for population modification gene drives that satisfy two previously-discussed target outcomes: a 50% reduction in clinical malaria incidence for a duration (window-of-protection) of at least three years, and a time-to-impact (considering a 50% reduction in clinical malaria incidence) of less than one year. We consider two African settings, Burkina Faso and Kenya, where gene drive mosquitoes are currently being researched, and consider three transmission intensities at each. For the gene drive product, we explored rates of homing and resistance allele generation, fitness costs associated with gene drive and non-functional resistance alleles, and efficacy of the effector gene(s) at reducing mosquito-to-human transmission. We found that when the window-of-protection criterion is satisfied, the time-to-impact criterion also is. Target outcomes are most influenced by the fitness cost associated with the gene drive allele and effector gene efficacy. Resistance allele parameters are highly influential on target outcomes, determining how long the gene drive allele persists in the population after most available wild-type alleles have been cleaved. Low rates of functional resistance allele generation are preferred, while costly non-functional resistance alleles will allow the drive allele to outcompete them. Homing rates already achieved for Anopheles gene drives do not need to be improved upon. A conundrum exists whereby the most important product parameters for predicting field efficacy are those tha

    Biostatistiques et épidémiologieMicrobiologie (bactériologie, virologie)Parasitologie et mycologieLicence : Creative Commons Attribution License This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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  • Article libreArticleEn anglais

    A modelling-chain linking climate science and decision-makers for future urban flood management in West Africa

    James D. Miller, Theo Vischel, Tazen Fowe, Geremy Panthou, Catherine Wilcox, Christopher M. Taylor, Emma Visman, Gnenakantanhan Coulibaly, Pepo Gonzalez, Richard Body, Gianni Vesuviano, Christophe Bouvier, Nanee Chahinian, Frédéric Cazenave

    Intensification of the hydrological cycle resulting from climate change in West Africa poses significant risks for the region’s rapidly urbanising cities, but limited research on flood risk has been undertaken at the urban domain scale. Furthermore, conventional climate models are unable to realistically represent the type of intense storms which dominate the West African monsoon. This paper presents a decision-first framing of climate research in co-production of a climate-hydrology-flooding modelling chain, linking scientists working on state-of-the-art regional climate science with decision-makers involved in city planning for future urban flood management in the city of Ouagadougou, Burkina Faso. The realistic convection-permitting model over Africa (CP4A) is applied at the urban scale for the first time and data suggest significant intensification of high-impact weather events and demonstrate the importance of considering the spatio-temporal scales in CP4A. Hydrological modelling and hydraulic modelling indicate increases in peak flows and flood extents in Ouagadougou in response to climate change which will be further exacerbated by future urbanisation. Advances in decision-makers’ capability for using climate information within Ouagadougou were observed, and key recommendations applicable to other regional urban areas are made. This study provides proof of concept that a decision-first modelling-chain provides a methodology for co-producing climate information that can, to some extent, bridge the usability gap between what scientists think is useful and what decision-makers need.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10113-022-01943-x.

    Santé publiqueLicence : Open Access http://creativecommons.org/licenses/by/4.0/ This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original autho
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  • Article libreArticleEn anglais

    A Molecular Method to Discriminate between Mass-Reared Sterile and Wild Tsetse Flies during Eradication Programmes That Have a Sterile Insect Technique Component

    BackgroundThe Government of Senegal has embarked several years ago on a project that aims to eradicate Glossina palpalis gambiensis from the Niayes area. The removal of the animal trypanosomosis would allow the development more efficient livestock production systems. The project was implemented using an area-wide integrated pest management strategy including a sterile insect technique (SIT) component. The released sterile male flies originated from a colony from Burkina Faso.Methodology/Principal FindingsMonitoring the efficacy of the sterile male releases requires the discrimination between wild and sterile male G. p. gambiensis that are sampled in monitoring traps. Before being released, sterile male flies were marked with a fluorescent dye powder. The marking was however not infallible with some sterile flies only slightly marked or some wild flies contaminated with a few dye particles in the monitoring traps. Trapped flies can also be damaged due to predation by ants, making it difficult to discriminate between wild and sterile males using a fluorescence camera and / or a fluorescence microscope. We developed a molecular technique based on the determination of cytochrome oxidase haplotypes of G. p. gambiensis to discriminate between wild and sterile males. DNA was isolated from the head of flies and a portion of the 5’ end of the mitochondrial gene cytochrome oxidase I was amplified to be finally sequenced. Our results indicated that all the sterile males from the Burkina Faso colony displayed the same haplotype and systematically differed from wild male flies trapped in Senegal and Burkina Faso. This allowed 100% discrimination between sterile and wild male G. p. gambiensis.Conclusions/SignificanceThis tool might be useful for other tsetse control campaigns with a SIT component in the framework of the Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC) and, more generally, for other vector or insect pest control programs. Author SummaryThe Gover

    Biologie cellulaire et moléculaireGénétiqueSanté publiqueLicence : Creative Commons Attribution License This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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  • Article libreArticleEn anglais

    A multi-component intervention to reduce bias during family planning visits: qualitative insights on implementation from Burkina Faso, Pakistan and Tanzania

    Corrina Moucheraud, Alexandra Wollum, Muhammad Ali Awan, William H. Dow, Willa Friedman, Jean-Louis Koulidiati, Amon Sabasaba, Manisha Shah, Zachary Wagner

    Beyond Bias was an intervention introduced in Burkina Faso, Pakistan and Tanzania, with the aim of reducing health worker bias toward young, unmarried and nulliparous women seeking family planning services. This study used qualitative methods – based on interviews with health workers who participated in the intervention, managers at health facilities that participated in the intervention, and policy and program stakeholders at the national level – to understand implementation experiences with the intervention. The results offer insights for organizations or countries seeking to implement Beyond Bias or similar programs, and point to some other key implementation challenges for multi-component interventions in lower-resource settings. The intervention, developed using a human-centered design approach, was seen as key for successful implementation but there were logistical challenges. The digital intervention was disruptive and distracting to many. In addition, the non-financial rewards intervention was perceived as complex, and some participants expressed feeling discouraged when they did not receive a reward. Beyond Bias did not sufficiently attend to the “outer setting,” and this was perceived as a major implementation barrier as it limited individuals’ capacity to fully achieve the desired behavior change; for example, space constraints meant that some health facilities could not ensure private services for all clients. There were scalability concerns related to cost, and there is uncertainty whether diversity of contexts (within and across countries) might constrain implementation of Beyond Bias at scale.

    Santé publiqueLicence : Open Access http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/publicdomain/zero/1.0/ This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as
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  • Article libreArticleEn anglais

    A multi-country study of the economic burden of dengue fever based on patient-specific field surveys in Burkina Faso, Kenya, and Cambodia

    BackgroundDengue fever is a rapidly growing public health problem in many parts of the tropics and sub-tropics in the world. While there are existing studies on the economic burden of dengue fever in some of dengue-endemic countries, cost components are often not standardized, making cross-country comparisons challenging. Furthermore, no such studies have been available in Africa.Methods/Principal findingsA patient-specific survey questionnaire was developed and applied in Burkina Faso, Kenya, and Cambodia in a standardized format. Multiple interviews were carried out in order to capture the entire cost incurred during the period of dengue illness. Both private (patient’s out-of-pocket) and public (non-private) expenditure were accessed to understand how the economic burden of dengue is distributed between private and non-private payers.A substantial number of dengue-confirmed patients were identified in all three countries: 414 in Burkina Faso, 149 in Kenya, and 254 in Cambodia. The average cost of illness for dengue fever was $26 (95% CI $23-$29) and $134 (95% CI $119-$152) per inpatient in Burkina Faso and Cambodia, respectively. In the case of outpatients, the average economic burden per episode was $13 (95% CI $23-$29) in Burkina Faso and $23 (95% CI $19-$28) in Kenya. Compared to Cambodia, public contributions were trivial in Burkina Faso and Kenya, reflecting that a majority of medical costs had to be directly borne by patients in the two countries.Conclusions/SignificanceThe cost of illness for dengue fever is significant in the three countries. In particular, the current study sheds light on the potential economic burden of the disease in Burkina Faso and Kenya where existing evidence is sparse in the context of dengue fever, and underscores the need to achieve Universal Health Coverage. Given the availability of the current (CYD-TDV) and second-generation dengue vaccines in the near future, our study outcomes can be used to guide decision makers in setting

    Biostatistiques et épidémiologieImmunologieSanté publiqueLicence : Creative Commons Attribution License This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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  • Article libreArticleEn anglais

    A Multi-Omics and Human Biomonitoring Approach to Assessing the Effectiveness of Fortified Balanced Energy–Protein Supplementation on Maternal and Newborn Health in Burkina Faso: A Study Protocol

    Fortified balanced energy–protein (BEP) supplementation is a promising intervention for improving maternal health, birth outcomes and infant growth in low- and middle-income countries. This nested biospecimen sub-study aimed to evaluate the physiological effect of multi-micronutrient-fortified BEP supplementation on pregnant and lactating women and their infants. Pregnant women (15–40 years) received either fortified BEP and iron–folic acid (IFA) (intervention) or IFA only (control) throughout pregnancy. The same women were concurrently randomized to receive either a fortified BEP supplement during the first 6 months postpartum in combination with IFA for the first 6 weeks (i.e., intervention) or the postnatal standard of care, which comprised IFA alone for 6 weeks postpartum (i.e., control). Biological specimens were collected at different timepoints. Multi-omics profiles will be characterized to assess the mediating effect of BEP supplementation on the different trial arms and its effect on maternal health, as well as birth and infant growth outcomes. The mediating effect of the exposome in the relationship between BEP supplementation and maternal health, birth outcomes and infant growth were characterized via biomonitoring markers of air pollution, mycotoxins and environmental contaminants. The results will provide holistic insight into the granular physiological effects of prenatal and postnatal BEP supplementation.

    Biologie cellulaire et moléculaireGénétiqueGynécologie-obstétriqueLicence : https://creativecommons.org/licenses/by/4.0/ Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ().
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  • Article libreArticleEn anglais

    A Multicenter Cost-of-Illness and Long-term Socioeconomic Follow-up Study in the Severe Typhoid Fever in Africa Program: Study Protocol

    Enusa Ramani, Seeun Park, Trevor Toy, Ursula Panzner, Ondari D Mogeni, Justin Im, Ligia Maria Cruz Espinoza, Hyon Jin Jeon, Gi Deok Pak, Hyeongwon Seo, Yun Chon, Raphaël Rakotozandrindrainy, Ellis Owusu-Dabo, Isaac Osei, Abdramane Bassiahi Soura, Mekonnen Teferi, Florian Marks, Vittal Mogasale

    AbstractBackgroundThere are limited data on typhoid fever cost of illness (COI) and economic impact from Africa. Health economic data are essential for measuring the cost-effectiveness of vaccination or other disease control interventions. Here, we describe the protocol and methods for conducting the health economic studies under the Severe Typhoid Fever in Africa (SETA) program.MethodsThe SETA health economic studies will rely on the platform for SETA typhoid surveillance in 4 African countries—Burkina Faso, Ethiopia, Ghana, and Madagascar. A COI and long-term socioeconomic study (LT-SES) will be its components. The COI will be assessed among blood culture–positive typhoid fever cases, blood culture–negative clinically suspected cases (clinical cases), and typhoid fever cases with pathognomonic gastrointestinal perforations (special cases). Repeated surveys using pretested questionnaires will be used to measure out-of-pocket expenses, quality of life, and the long-term socioeconomic impact. The cost of resources consumed for diagnosis and treatment will be collected at health facilities.ResultsResults from these studies will be published in peer-reviewed journals and presented at scientific conferences to make the data available to the wider health economics and public health research communities.ConclusionsThe health economic data will be analyzed to estimate the average cost per case, the quality of life at different stages of illness, financial stress due to illness, and the burden on the family due to caregiving during illness. The data generated are expected to be used in economic analysis and policy making on typhoid control interventions in sub-Saharan Africa.

    Biostatistiques et épidémiologieImmunologieSanté publiqueLicence : http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
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  • Article libreArticleEn anglais

    A Multicountry Comparison of Three Coverage Evaluation Survey Sampling Methodologies for Neglected Tropical Diseases

    Katherine Gass, Michael Deming, Roland Bougma, Franck Drabo, Edridah Muheki Tukahebwa, Square Mkwanda, Reina Teresa Velasquez, Rosa Elena Mejia, Pamela Sabina Mbabazi

    Abstract.Coverage evaluation surveys (CESs) are an important complement to routinely reported drug coverage estimates following mass drug administration for neglected tropical diseases (NTDs). Although the WHO recommends the routine use of CESs, they are rarely implemented. Reasons for this low uptake are multifaceted; one is uncertainty on the best sampling method. We conducted a multicountry study to compare the statistical characteristics, cost, time, and complexity of three commonly used CES sampling methods: the Expanded Program on Immunization’s (EPI’s) 30 × 7 cluster survey, a stratified design with systematic sampling within strata to enable lot quality assurance sampling (S-LQAS) decision rules, and probability sampling with segmentation (PSS). The three CES methods were used in Burkina Faso, Honduras, Malawi, and Uganda, and results were compared across the country sites. All three CES methods were found to be feasible. The S-LQAS approach took the least amount of time to complete and, consequently, was the least expensive; however, all three methods cost less than $5,000 per district. The PSS design resulted in an unbiased, equal-probability sample of the target populations. By contrast, the EPI approach had inherent bias related to the selection of households. Because of modifications needed to maintain feasibility, the S-LQAS method also resulted in a non-probability sample with less precision than the other two methods. Given the comparable cost and time of the three sampling methods and the statistical advantages of the PSS method, the PSS method was deemed to be the best for CESs in NTD programs.

    Biostatistiques et épidémiologieImmunologiePharmacologieLicence : Creative Commons Attribution (CC-BY) License This is an open-access article distributed under the terms of the, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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  • Article libreArticleEn anglais

    A Multilingual Tool for Standardized Laboratory Biosafety and Biosecurity Assessment and Monitoring

    Arnaud Orelle, Abdoulaye Nikiema, Arsen Zakaryan, Adilya A. Albetkova, Mah-Séré Keita, Mark A. Rayfield, Leonard F. Peruski, Antoine Pierson

    Control of infectious diseases requires the handling of infectious materials by both clinical and public health laboratories with exposure risks for laboratory personnel and environment. A comprehensive tool for assessing the capacity to manage these risks could enable the development of action plans for mitigation. Under the framework of the Global Health Security Agenda action package for biosafety and biosecurity, the authors developed a tool dedicated to assessing laboratory biosafety and biosecurity. The Biosafety and Biosecurity Laboratory Assessment Tool (BSS LAT) assesses the status of all laboratory biosafety core requirements across 10 different modules. It consists of a standardized spreadsheet-based tool that provides automatic scoring. It is designed to support national, regional, and global efforts to strengthen biosafety in clinical, public health, and veterinary laboratories. The BSS LAT was first used in Burkina Faso in collaboration with the African Society for Laboratory Medicine and the US Centers for Disease Control and Prevention to support the country in strengthening their biorisk management system. Since then, it has been successfully used in other countries (ie, Armenia, Burundi, Cameroon, Ghana, Guinea, Kazakhstan, Liberia), various settings (medical and veterinary laboratories), and translated into several languages (eg, English, French, Russian). The BSS LAT is a multipurpose tool that assists with standardization of biosafety and biosecurity requirements for all laboratories working with infectious materials, serves as a self-assessment guide for laboratories to develop improvement plans and reinforce capacities, and serves as a training guide for individual laboratories and networks or at the national level. The BSS LAT can also be used as a monitoring tool for the assessment of biosafety and biosecurity across all laboratories working with infectious materials at the national, regional, and global levels.

    Santé publiqueLicence : http://creativecommons.org/licenses/by/4.0 This Open Access article is distributed under the terms of the Creative Commons License (), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.
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  • Article libreArticleEn anglais

    A Multiplex Serological Assay to Evaluate the Antibody Responses to a Set of Plasmodium falciparum Antigens and Their Protective Role Against Malaria in Children Aged 1.5 to 12 Years Living in a Highly Seasonal Malaria Transmission Area of Burkina Faso

    Background/Objectives: Understanding the seroepidemiology of P. falciparum antibody responses is essential for assessing the acquisition of natural immunity and may guide interventions that impact the acquisition of immunity against malaria in endemic areas. This study assessed the association between antigen-specific IgG responses and protection against P. falciparum infection in children from Burkina Faso. Methods: Children aged 1.5 to 12 years were followed using cross-sectional and longitudinal approaches. IgG responses to 16 P. falciparum antigens were measured using a multiplex assay and analyzed by age group and malaria infection status. Associations between antibody levels and clinical malaria risk were assessed using incidence rate ratios (IRRs), and predictive performance of antibody combinations was evaluated using ROC analysis. Results: IgG responses to AMA1, CSP, and MSP2 CH150 showed weak but significant positive correlation with age. Children aged 5–12 years had higher antibody levels than younger children aged 1.5–5 years. Uninfected children had higher levels of antibodies to EBA181 RIII-V, Rh5.1, and SEA1, while infected children had elevated AMA1 and MSP2 CH150. Anti-GLURP R2 and anti-Rh5.1 antibodies were associated with reduced malaria risk (adjusted IRR = 0.52 and 0.40, respectively). The antibody combination of AMA1, GLURP R2, and Etramp5 Ag1 showed the best predictive performance (AUC = 0.70). Conclusions: This study underlines the value of less-studied antibodies (Etramp5 Ag1, Rh5.1, HSP40 Ag1) for diagnosing and protecting against malaria, opening up prospects for the development of more effective tests and targeted vaccine approaches. The variability of responses according to age and infection status calls for further studies to optimize prevention strategies.

    Biostatistiques et épidémiologieParasitologie et mycologieImmunologieLicence : https://creativecommons.org/licenses/by/4.0/ Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ().
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  • Article libreArticleEn anglais

    A Non-Coding Fc Gamma Receptor Cis-Regulatory Variant within the 1q23 Gene Cluster Is Associated with Plasmodium falciparum Infection in Children Residing in Burkina Faso

    Antibodies play a crucial role in activating protective immunity against malaria by interacting with Fc-gamma receptors (FcγRs). Genetic variations in genes encoding FcγRs can affect immune cell responses to the parasite. In this study, our aim was to investigate whether non-coding variants that regulate FcγR expression could influence the prevalence of Plasmodium falciparum infection. Through bioinformatics approaches, we selected expression quantitative trait loci (eQTL) for FCGR2A, FCGR2B, FCGR2C, FCGR3A, and FCGR3B genes encoding FcγRs (FCGR), in whole blood. We prioritized two regulatory variants, rs2099684 and rs1771575, located in open genomic regions. These variants were identified using RegVar, ImmuNexUT, and transcription factor annotations specific to immune cells. In addition to these, we genotyped the coding variants FCGR2A/rs1801274 and FCGR2B/rs1050501 in 234 individuals from a malaria-endemic area in Burkina Faso. We conducted age and family-based analyses to evaluate associations with the prevalence of malarial infection in both children and adults. The analysis revealed that the regulatory rs1771575-CC genotype was predicted to influence FCGR2B/FCGR2C/FCGR3A transcripts in immune cells and was the sole variant associated with a higher prevalence of malarial infection in children. In conclusion, this study identifies the rs1771575 cis-regulatory variant affecting several FcγRs in myeloid and neutrophil cells and associates it with the inter-individual capacity of children living in Burkina Faso to control malarial infection.

    Biologie cellulaire et moléculaireGénétiqueBiostatistiques et épidémiologieLicence : https://creativecommons.org/licenses/by/4.0/ Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ().
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  • Article libreArticleEn anglais

    A non-destructive sugar-feeding assay for parasite detection and estimating the extrinsic incubation period of Plasmodium falciparum in individual mosquito vectors

    Edwige Guissou, Jessica L. Waite, Matthew Jones, Andrew S. Bell, Eunho Suh, Koudraogo B. Yameogo, Nicaise Djègbè, Dari F. Da, Domonbabele F. D. S. Hien, Rakiswende S. Yerbanga, Anicet G. Ouedraogo, Kounbobr Roch. Dabiré, Anna Cohuet, Matthew B. Thomas, Thierry Lefèvre

    Despite its epidemiological importance, the time Plasmodium parasites take to achieve development in the vector mosquito (the extrinsic incubation period, EIP) remains poorly characterized. A novel non-destructive assay designed to estimate EIP in single mosquitoes, and more broadly to study Plasmodium–Anopheles vectors interactions, is presented. The assay uses small pieces of cotton wool soaked in sugar solution to collect malaria sporozoites from individual mosquitoes during sugar feeding to monitor infection status over time. This technique has been tested across four natural malaria mosquito species of Africa and Asia, infected with Plasmodium falciparum (six field isolates from gametocyte-infected patients in Burkina Faso and the NF54 strain) and across a range of temperatures relevant to malaria transmission in field conditions. Monitoring individual infectious mosquitoes was feasible. The estimated median EIP of P. falciparum at 27 °C was 11 to 14 days depending on mosquito species and parasite isolate. Long-term individual tracking revealed that sporozoites transfer onto cotton wool can occur at least until day 40 post-infection. Short individual EIP were associated with short mosquito lifespan. Correlations between mosquito/parasite traits often reveal trade-offs and constraints and have important implications for understanding the evolution of parasite transmission strategies.

    Biostatistiques et épidémiologieParasitologie et mycologieMaladies infectieuses et tropicalesLicence : Open Access http://creativecommons.org/licenses/by/4.0/ This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original autho
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  • Article libreArticleEn anglais

    A Non-Inferiority, Individually Randomized Trial of Intermittent Screening and Treatment versus Intermittent Preventive Treatment in the Control of Malaria in Pregnancy

    BackgroundThe efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPTp-SP) in pregnancy is threatened in parts of Africa by the emergence and spread of resistance to SP. Intermittent screening with a rapid diagnostic test (RDT) and treatment of positive women (ISTp) is an alternative approach.Methods and FindingsAn open, individually randomized, non-inferiority trial of IPTp-SP versus ISTp was conducted in 5,354 primi- or secundigravidae in four West African countries with a low prevalence of resistance to SP (The Gambia, Mali, Burkina Faso and Ghana). Women in the IPTp-SP group received SP on two or three occasions whilst women in the ISTp group were screened two or three times with a RDT and treated if positive for malaria with artemether-lumefantrine (AL). ISTp-AL was non-inferior to IPTp-SP in preventing low birth weight (LBW), anemia and placental malaria, the primary trial endpoints. The prevalence of LBW was 15.1% and 15.6% in the IPTp-SP and ISTp-AL groups respectively (OR = 1.03 [95% CI: 0.88, 1.22]). The mean hemoglobin concentration at the last clinic attendance before delivery was 10.97g/dL and 10.94g/dL in the IPTp-SP and ISTp-AL groups respectively (mean difference: -0.03 g/dL [95% CI: -0.13, +0.06]). Active malaria infection of the placenta was found in 24.5% and in 24.2% of women in the IPTp-SP and ISTp-AL groups respectively (OR = 0.95 [95% CI 0.81, 1.12]). More women in the ISTp-AL than in the IPTp-SP group presented with malaria parasitemia between routine antenatal clinics (310 vs 182 episodes, rate difference: 49.4 per 1,000 pregnancies [95% CI 30.5, 68.3], but the number of hospital admissions for malaria was similar in the two groups.ConclusionsDespite low levels of resistance to SP in the study areas, ISTp-AL performed as well as IPTp-SP. In the absence of an effective alternative medication to SP for IPTp, ISTp-AL is a potential alternative to IPTp in areas where SP resistance is high. It may also have a

    Biostatistiques et épidémiologieMicrobiologie (bactériologie, virologie)Parasitologie et mycologieLicence : This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
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    A novel method for mapping village-scale outdoor resting microhabitats of the primary African malaria vector, Anopheles gambiae

    Julius R. Dewald, Douglas O. Fuller, Günter C. Müller, John C. Beier

    BackgroundKnowledge of Anopheles resting habitats is needed to advance outdoor malaria vector control. This study presents a technique to map locations of resting habitats using high-resolution satellite imagery (world view 2) and probabilistic Dempster-Shafer (D-S) modelling, focused on a rural village in southern Mali, West Africa where field sampling was conducted to determine outdoor habitat preferences of Anopheles gambiae, the main vector in the study area.MethodsA combination of supervised and manual image classification was used to derive an accurate land-cover map from the satellite image that provided classes (i.e., photosynthetically active vegetation, water bodies, wetlands, and buildings) suitable for habitat assessment. Linear fuzzy functions were applied to the different image classes to scale resting habitat covariates into a common data range (0–1) with fuzzy breakpoints parameterized experimentally through comparison with mosquito outdoor resting data. Fuzzy layers were entered into a Dempster-Shafer (D-S) weight-of-evidence model that produced pixel-based probability of resting habitat locations.ResultsThe D-S model provided a highly detailed suitability map of resting locations. The results indicated a significant difference (p < 0.001) between D-S values at locations positive for An. gambiae and a set of randomly sampled points. Further, a negative binomial regression indicated that although the D-S estimates did not predict abundance (p > 0.05) subsequent analysis suggested that the D-S modelling approach may provide a reasonable estimate locations of low-to-medium An. gambiae density. These results suggest that that D-S modelling performed well in identifying presence points and specifically resting habitats.ConclusionThe use of a D-S modelling framework for predicting the outdoor resting habitat locations provided novel information on this little-known aspect of anopheline ecology. The technique used here may be applied more broadly at differ

    Parasitologie et mycologieMaladies infectieuses et tropicalesLicence : Open Access http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/publicdomain/zero/1.0/ This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (), which permits unrestricted use, distribution, and reproduction in any medium, provid
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  • Article libreArticleEn anglais

    A Novel Newborn Screening Program for Sickle Cell Disease in Nigeria

    Newborn screening for sickle cell disease (SCD) is sparse in sub-Saharan Africa. The leadership of the Aminu Kano Teaching Hospital (AKTH) in Kano, Nigeria, with the support of local religious authorities, established a groundbreaking SCD newborn screening program that has become the standard of care for pregnant women and their newborns. Our program includes (1) prenatal genetic counseling for all pregnant women in the antenatal clinic, (2) newborn screening, (3) postnatal genetic counseling for parents of newborns diagnosed with SCD and SCT, and (4) referral of newborns with SCD for follow-up in the SCD Comprehensive Care Clinic by 3 months of age. From September 2020 to December 2023, the team screened 7530 infants for SCD at the AKTH, identifying 126 (1.7%) infants with SCD and 1546 (20.5%) with SCT. Of these, 93 (73.8%) newborns with SCD received individualized genetic counseling, and 43 (46%) were referred to the SCD Comprehensive Care Clinic before 3 months. Group genetic counseling was provided to the parents of 778 (50.3%) of newborns identified with SCT. The SCD newborn screening at the AKTH is now standard care, indicating the viability of sustaining an SCD newborn screening program that provides pre- and postnatal genetic counseling and comprehensive SCD care within a low-income setting.

    Biologie cellulaire et moléculaireGénétiqueHématologieLicence : https://creativecommons.org/licenses/by/4.0/ Published by MDPI on behalf of the International Society for Neonatal Screening. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ().
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    A Novel qPCR Assay for the Detection of African Animal Trypanosomosis in Trypanotolerant and Trypanosusceptible Cattle Breeds

    This study was conducted to (i) determine the prevalence of African Animal Trypanosomosis (AAT) in tsetse challenged areas, (ii) compare conventional with qPCR detection systems and (iii) evaluate the host genetic background and biology as risk factors. AAT prevalence studies are often confronted with low levels of parasitaemia. Hence, we designed a novel qPCR assay using primers and species specific probes amplifying the Internal Transcribed Spacer 1 (ITS1) gene. Thereby all three AAT species could be detected simultaneously. 368 individuals from three cattle types (Baoulé, Zebu and hybrids) originating from 72 farms in Burkina Faso were analysed. Farmers were interviewed and morphometric measurements of the cattle taken. A chi-squared test and a logistic regression model were calculated to detect associations with infection. In our study, the overall rate of prevalence detected with the novel qPCR assay was 11.14%. Compared to conventional PCR we identified a concordance of 91.30%. We tested 41 animals positive for trypanosome DNA, five animals showed multiple infections. Zebus were twice as often infected (21.74%) compared to Baoulé (9.70%) and hybrids (9.57%). Trypanosoma vivax is the dominant species (9.24%), as compared to T. congolense (2.44%) and T. brucei (0.82%). The chi-squared tests linking the infection events to the breeds (Zebu vs. Baoulé and Zebu vs. hybrids) were on the border of significance. No significant association with other tested parameters could be detected. We introduce a novel qPCR technique for the fast, sensitive and simultaneous detection of the three AAT species. Our results suggest that associations with breed and infection exist since Zebu cattle are more likely to be infected compared to Baoulé and hybrids. Indigenous taurine cattle breeds, like the Baoulé, therefore provide a unique and valuable genetic resource. Author SummaryAfrican Animal Trypanosomosis (AAT) is a neglected tropical disease heavily impacting on the poor. Sensit

    Biologie cellulaire et moléculaireGénétiqueBiostatistiques et épidémiologieLicence : This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
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    A Paper-Based Test for Screening Newborns for Sickle Cell Disease

    Nathaniel Z. Piety, Alex George, Sonia Serrano, Maria R. Lanzi, Palka R. Patel, Maria P. Noli, Silvina Kahan, Damian Nirenberg, João F. Camanda, Gladstone Airewele, Sergey S. Shevkoplyas

    The high cost, complexity and reliance on electricity, specialized equipment and supplies associated with conventional diagnostic methods limit the scope and sustainability of newborn screening for sickle cell disease (SCD) in sub-Saharan Africa and other resource-limited areas worldwide. Here we describe the development of a simple, low-cost, rapid, equipment- and electricity-free paper-based test capable of detecting sickle hemoglobin (HbS) in newborn blood samples with a limit of detection of 2% HbS. We validated this newborn paper-based test in a cohort of 159 newborns at an obstetric hospital in Cabinda, Angola. Newborn screening results using the paper-based test were compared to conventional isoelectric focusing (IEF). The test detected the presence of HbS with 81.8% sensitivity and 83.3% specificity, and identified SCD newborns with 100.0% sensitivity and 70.7% specificity. The use of the paper-based test in a two-stage newborn screening process could have excluded about 70% of all newborns from expensive confirmatory testing by IEF, without missing any of the SCD newborns in the studied cohort. This study demonstrates the potential utility of the newborn paper-based test for reducing the overall cost of screening newborns for SCD and thus increasing the practicality of universal newborn SCD screening programs in resource-limited settings.

    Biostatistiques et épidémiologieHématologieGynécologie-obstétriqueLicence : http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the mat
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    A participatory approach to move towards a One Health surveillance system for anthrax in Burkina Faso

    The One Health approach calls for collaboration across various sectors and different scales to improve understanding of complex health issues. Regarding epidemiological surveillance, this implies the development of integrated systems that link several surveillance components operating in different domains (human, domestic animals, environment) and involving several actor networks. However, surveillance continues to operate in a very compartmentalized way, with little interaction between sectoral institutions and with the community for the governance and operation of surveillance activities. This is partly explained by the insufficient consideration of the local context and the late involvement of national stakeholders when developing programmes that aimed at strengthening the integration of surveillance. In low- and middle-income countries in particular, there is a strong influence of external partners on the development of intersectoral programmes, including surveillance systems. In this context, we developed and implemented a participatory planning process to support stakeholders of the surveillance system of anthrax in Burkina Faso, in the definition of the One Health surveillance system they wish for and of the pathway to reach it. The workshop produced an action plan that reflects the views and perspectives of representatives of the different categories of stakeholders and beneficiaries of surveillance. In addition, the participation of stakeholders in this participatory co-construction process has also improved their knowledge and mutual understanding, fostering a climate of trust conducive to further collaboration for surveillance activities. However, the quality of the participation raises some questions over the results, and contextual factors may have influenced the process. This underlines the need to include a monitoring and evaluation plan in the process to assess its implementation and ability to produce One Health surveillance modalities that are appr

    Biostatistiques et épidémiologieSanté publiqueLicence : Creative Commons Attribution License This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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    A Pathovar of Xanthomonas oryzae Infecting Wild Grasses Provides Insight Into the Evolution of Pathogenicity in Rice Agroecosystems

    Jillian M. Lang, Alvaro L. Pérez-Quintero, Ralf Koebnik, Elysa DuCharme, Soungalo Sarra, Hinda Doucoure, Ibrahim Keita, Janet Ziegle, Jonathan M. Jacobs, Ricardo Oliva, Ousmane Koita, Boris Szurek, Valérie Verdier, Jan E. Leach

    Xanthomonas oryzae (Xo) are globally important rice pathogens. Virulent lineages from Africa and Asia and less virulent strains from the United States have been well characterized. Xanthomonas campestris pv. leersiae (Xcl), first described in 1957, causes bacterial streak on the perennial grass, Leersia hexandra, and is a close relative of Xo. L. hexandra, a member of the Poaceae, is highly similar to rice phylogenetically, is globally ubiquitous around rice paddies, and is a reservoir of pathogenic Xo. We used long read, single molecule real time (SMRT) genome sequences of five strains of Xcl from Burkina Faso, China, Mali, and Uganda to determine the genetic relatedness of this organism with Xo. Novel transcription activator-like effectors (TALEs) were discovered in all five strains of Xcl. Predicted TALE target sequences were identified in the Leersia perrieri genome and compared to rice susceptibility gene homologs. Pathogenicity screening on L. hexandra and diverse rice cultivars confirmed that Xcl are able to colonize rice and produce weak but not progressive symptoms. Overall, based on average nucleotide identity (ANI), type III (T3) effector repertoires, and disease phenotype, we propose to rename Xcl to X. oryzae pv. leersiae (Xol) and use this parallel system to improve understanding of the evolution of bacterial pathogenicity in rice agroecosystems.

    Biologie cellulaire et moléculaireGénétiqueSanté publiqueLicence : This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journa
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    A PCR-RFLP method for genotyping of inversion 2Rc in Anopheles coluzzii

    Raquel Montanez‑Gonzalez, Alexandra C. Vallera, Maria Calzetta, Verena Pichler, Rachel R. Love, Moussa W. Guelbeogo, Roch K. Dabire, Marco Pombi, Carlo Costantini, Frederic Simard, Alessandra della Torre, Nora J. Besansky

    BackgroundGenotyping of polymorphic chromosomal inversions in malaria vectors such as An. coluzzii Coetzee & Wilkerson is important, both because they cause cryptic population structure that can mislead vector analysis and control and because they influence epidemiologically relevant eco-phenotypes. The conventional cytogenetic method of genotyping is an impediment because it is labor intensive, requires specialized training, and can be applied only to one gender and developmental stage. Here, we circumvent these limitations by developing a simple and rapid molecular method of genotyping inversion 2Rc in An. coluzzii that is both economical and field-friendly. This inversion is strongly implicated in temporal and spatial adaptations to climatic and ecological variation, particularly aridity.MethodsUsing a set of tag single-nucleotide polymorphisms (SNPs) strongly correlated with inversion orientation, we identified those that overlapped restriction enzyme recognition sites and developed four polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) assays that distinguish alternative allelic states at the tag SNPs. We assessed the performance of these assays using mosquito population samples from Burkina Faso that had been cytogenetically karyotyped as well as genotyped, using two complementary high-throughput molecular methods based on tag SNPs. Further validation was performed using mosquito population samples from additional West African (Benin, Mali, Senegal) and Central African (Cameroon) countries.ResultsOf four assays tested, two were concordant with the 2Rc cytogenetic karyotype > 90% of the time in all samples. We recommend that these two assays be employed in tandem for reliable genotyping. By accepting only those genotypic assignments where both assays agree, > 99% of assignments are expected to be accurate.ConclusionsWe have developed tandem PCR-RFLP assays for the accurate genotyping of inversion 2Rc in An. coluzzii. Because this a

    Biologie cellulaire et moléculaireGénétiqueBiostatistiques et épidémiologieLicence : Open Access http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/publicdomain/zero/1.0/ This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as
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    A Phase 1b Randomized, Controlled, Double-Blinded Dosage-Escalation Trial to Evaluate the Safety, Reactogenicity and Immunogenicity of an Adenovirus Type 35 Based Circumsporozoite Malaria Vaccine in Burkinabe Healthy Adults 18 to 45 Years of Age

    BackgroundAd35.CS.01 is a pre-erythrocytic malaria candidate vaccine. It is a codon optimized nucleotide sequence representing the P. falciparum circumsporozoite (CS) surface antigen inserted in a replication deficient Adenovirus 35 backbone. A Phase 1a trial has been conducted in the USA in naïve adults and showed that the vaccine was safe. The aim of this study is to assess the safety and immunogenicity of ascending dosages in sub Saharan Africa.MethodsA double blind, randomized, controlled, dose escalation, phase Ib trial was conducted in a rural area of Balonghin, the Saponé health district (Burkina Faso). Forty-eight healthy adults aged 18-45 years were randomized into 4 cohorts of 12 to receive three vaccine doses (day 0, 28 and 84) of 109, 1010, 5X1010, 1011 vp of Ad35.CS.01 or normal saline by intra muscular injection. Subjects were monitored carefully during the 14 days following each vaccination for non serious adverse events. Severe and serious adverse events were collected throughout the participant study duration (12 months from the first vaccination). Humoral and cellular immune responses were measured on study days 0, 28, 56, 84, 112 and 140.ResultsOf the forty-eight subjects enrolled, forty-four (91.7%) received all three scheduled vaccine doses. Local reactions, all of mild severity, occurred in thirteen (27.1%) subjects. Severe (grade 3) laboratory abnormalities occurred in five (10.4%) subjects. One serious adverse event was reported and attributed to infection judged unrelated to vaccine. The vaccine induced both antibody titers and CD8 T cells producing IFNγ and TNFα with specificity to CS while eliciting modest neutralizing antibody responses against Ad35.ConclusionStudy vaccine Ad35.CS.01 at four different dose levels was well-tolerated and modestly immunogenic in this population. These results suggest that Ad35.CS.01 should be further investigated for preliminary efficacy in human challenge models and as part of heterologous prime-boost vacci

    Biologie cellulaire et moléculaireGénétiqueBiostatistiques et épidémiologieLicence : This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
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