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BACKGROUND: Randomized controlled trials found that twice-yearly mass azithromycin administration (MDA) reduces childhood mortality, presumably by reducing infection burden. World Health Organization (WHO) issued conditional guidelines for mass azithromycin administration in high-mortality settings in sub-Saharan Africa given concerns for antibiotic resistance. While prolonged twice-yearly MDA has been shown to increase antibiotic resistance in small randomized controlled trials, the objective of this study was to determine if macrolide and non-macrolide resistance in the gut increases with the duration of azithromycin MDA in a larger setting. METHODS AND FINDINGS: The Macrolide Oraux pour Réduire les Décès avec un Oeil sur la Résistance (MORDOR) study was conducted in Niger from December 2014 to June 2020. It was a cluster-randomized trial of azithromycin (A) versus placebo (P) aimed at evaluating childhood mortality. This is a sub-study in the MORDOR trial to track changes in antibiotic resistance after prolonged azithromycin MDA. A total of 594 communities were eligible. Children 1 to 59 months in 163 randomly chosen communities were eligible to receive treatment and included in resistance monitoring. Participants, staff, and investigators were masked to treatment allocation. At the conclusion of MORDOR Phase I, by design, all communities received an additional year of twice-yearly azithromycin treatments (Phase II). Thus, at the conclusion of Phase II, the treatment history (1 letter per 6-month period) for the participating communities was either (PP-PP-AA) or (AA-AA-AA). In Phase III, participating communities were then re-randomized to receive either another 3 rounds of azithromycin or placebo, thus resulting in 4 treatment histories: Group 1 (AA-AA-AA-AA-A, N = 51), Group 2 (PP-PP-AA-AA-A, N = 40), Group 3 (AA-AA-AA-PP-P, N = 27), and Group 4 (PP-PP-AA-PP-P, N = 32). Rectal swabs from each child (N = 5,340) were obtained 6 months after the last treatment. Each child contributed 1 rectal swab and these were pooled at the community level, processed for DNA-seq, and analyzed for genetic resistance determinants. The primary prespecified outcome was macrolide resistance determinants in the gut. Secondary outcomes were resistance to beta-lactams and other antibiotic classes. Communities recently randomized to azithromycin (groups 1 and 2) had significantly more macrolide resistance determinants than those recently randomized to placebo (groups 3 and 4) (fold change 2.18, 95% CI 1.5 to 3.51, Punadj < 0.001). However, there was no significant increase in macrolide resistance in communities treated 4.5 years (group 1) compared to just the most recent 2.5 years (group 2) (fold change 0.80, 95% CI 0.50 to 1.00, Padj = 0.010), or between communities that had been treated for 3 years in the past (group 3) versus just 1 year in the past (group 4) (fold change 1.00, 95% CI 0.78 to 2.35, Padj = 0.52). We also found no significant differences for beta-lactams or other antibiotic classes. The main limitations of our study were the absence of phenotypic characterization of resistance, no complete placebo arm, and no monitoring outside of Niger limiting generalizability. CONCLUSIONS: In this study, we observed that mass azithromycin distribution for childhood mortality among preschool children in Niger increased macrolide resistance determinants in the gut but that resistance may plateau after 2 to 3 years of treatment. Co-selection to other classes needs to be monitored. TRIAL REGISTRATION: NCT02047981 https://classic.clinicaltrials.gov/ct2/show/NCT02047981.

Abstract Ivermectin (IVM) has been proposed as a new tool for malaria control as it is toxic on vectors feeding on treated humans or cattle. Nevertheless, IVM may have a direct mosquitocidal effect when applied on bed nets or sprayed walls. The potential for IVM application as a new insecticide for long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) was tested in this proof-of-concept study in a laboratory and semi-field environment. Laboratory-reared, insecticide-susceptible Kisumu Anopheles gambiae were exposed to IVM on impregnated netting materials and sprayed plastered- and mud walls using cone bioassays. The results showed a direct mosquitocidal effect of IVM on this mosquito strain as all mosquitoes died by 24 h after exposure to IVM. The effect was slower on the IVM-sprayed walls compared to the treated nettings. Further work to evaluate possibility of IVM as a new insecticide formulation in LLINs and IRS will be required.

The focus of this study was to assess the environmental impact of the BATOKE oil sludge dump. A field visit was conducted to evaluate the condition of the site, followed by the sampling of oil sludge, BATOKE river water, soil, and locally grown manioc and macabo tubers. Subsequent physico-chemical characterization revealed parameters such as pH, electrical conductivity, total hydrocarbons, COD, BOD5, TSS, major cations and anions, as well as heavy metals including iron, copper, zinc, nickel, chromium, lead, cadmium, mercury, arsenic, calcium, potassium, titanium, zirconium, and rubidium. The environmental impact was assessed using the Contamination Index calculation and the Correlation Matrix. Results indicated that most physical parameters met standards, except for the electrical conductivity of water and soil. However, elevated levels of iron, chromium, lead, cadmium, mercury, arsenic, and ammonium ion were found in the BATOKE River water. The soil showed heavy contamination with various metals, and cassava and macabo tubers were also found to be contaminated. The contamination index calculations confirmed severe pollution in the BATOKE environment, with a risk of further escalation without remediation efforts.

Abstract The common solution for protecting p‐type semiconductors against photocorrosion in a photo‐electrochemical (PEC) cell is by applying a TiO2 over‐layer via atomic layer deposition (ALD). However, for the case of CuBi2O4 (CBO), this approach leads to a significant decline in electrode performance, despite the small conduction band offset between CBO and TiO2. Here, electrochemical impedance spectroscopy (EIS) under light illumination is used to study how to enhance charge transport in CuBi2O4/TiO2 photocathodes. A 15 nm TiO2 overlayer enables a small charge transfer resistance to the electrolyte while preserving the performance and stability of the CBO film. When increasing the TiO2 thickness from 15 to 20 nm, the photogenerated currents decrease by 74%. The EIS data are fit with an equivalent circuit model that enabled to extract the charge transfer resistances, capacitances, and time constants that influence the PEC performance of the electrode as a function of the TiO2 layer thickness, together with the flat‐band potentials and doping densities of both the CBO and TiO2 layers under light illumination. The decline in performance is attributed to accumulation and recombination of photogenerated carriers at the CBO‐TiO2 interface, due to a band mismatch between the two semiconductors.

Synthetic insecticides used worldwide are not environmentally friendly, so there is need for harmless insecticides from bio-sources. The present work is therefore aimed at studying the adsorption of M. charantia leaf extract (EL) on a clay/arabic gum composite. Two composite samples containing clay/arabic gum of 2.5 g/7.5 g noted CP1 and 2.5 g/15 g noted CP2 were each prepared and characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM). Results show that the clay used is of the Kaolinite (kao) type. Arabic gum made it possible to increase the interlayer spaces of kao of the order of 2θ of 12.16° to 2θ of 7.25° and 6.60° for composite 1 (CP1) and composite 2 (CP2) respectively. Results best fitted Freundlich isotherm model for all the adsorbents with CP2 having better adsorption capacity of 9.05 (mg/g)(L/mg)1/n compared to 5.32 and 5.65 (mg/g)(L/mg)1/n for CP1 and kao respectively. The adsorption process was exothermic, non-spontaneous and occurred by physisorption mechanism. The pseudo-second-order kinetic model best fitted the experimental data for the samples with adsorption occurring faster on CP1 (0.20 g/mg/min) compared to kao (0.06 g/mg/min) and CP1 (0.04 g/mg/min). Results show that arabic gum composite with increasing mass of the arabic gum is more effective in binding M. charantia leaf extract. The arabic gum composite with adsorbed M. charantia leaf extract could be used as an insecticide powder for the preservation of foodstuffs

Abstract Background In 2022 the WHO recommended the discretionary expansion of the eligible age range for seasonal malaria chemoprevention (SMC) to children older than 4 years. Older children are at lower risk of clinical disease and severe malaria so there has been uncertainty about the cost-benefit for national control programmes. However, emerging evidence from laboratory studies suggests protecting school-age children reduces the infectious reservoir for malaria and may significantly impact on transmission. This study aimed to assess whether these effects were detectable in the context of a routinely delivered SMC programme. Methods In 2021 the Gambia extended the maximum eligible age for SMC from 4 to 9 years. We conducted a prospective population cohort study over the 2021 malaria transmission season covering 2210 inhabitants of 10 communities in the Upper River Region, and used a household-level mixed modelling approach to quantify impacts of SMC on malaria transmission. Results We demonstrate that the hazard of clinical malaria in older participants aged 10+ years ineligible for SMC decreases by 20% for each additional SMC round per child 0–9 years in the same household. Older inhabitants also benefit from reduced risk of asymptomatic infections in high SMC coverage households. Spatial autoregression tests show impacts are highly localised, with no detectable spillover from nearby households. Conclusions Evidence for the transmission-reducing effects of extended-age SMC from routine programmes implemented at scale has been previously limited. Here we demonstrate benefits to the entire household, indicating such programmes may be more cost-effective than previously estimated.

The preservation of post-harvest losses of cowpeas constitutes a major challenge for producers worldwide. Therefore, the aim of this work was to investigate the nutritional qualities of cowpea seeds treated with a bio-insecticide formulated from M. charantia leaves extract in association with gum arabic/kaolinite composite. Three bio-insecticides were formulated using different ethyl acetate, hexane and methanol solvents. These bio-insecticides were obtained by introducing each into a bottle, 10 g of composite in 10 mL of a solution (1 mg/L of extract each extract). However, 5 doses of each formulation (1 %–5 %) were prepared. Each dose of insecticide powders received 20 g of cowpea seeds and then infested with 10 C. maculatus previously starved for 48 h. Then, the biochemical parameters of untreated and treated cowpea seeds using the methanol formulation were evaluated. The obtained results showed that insecticide formulated at 5 % with methanol induced 100 % mortality rate on the second day of treatment with a lethal dose of 0.10 % which is related to its high content of triterpenes and polyphenols. The untreated (UWH) and treated (TWH) seeds without husk have the same contents of ash (2.19 %), proteins (29.14 %), fibers (2.69 %), vitamin C (147.32 mg/100 g) and carbohydrates (53.20 %), while untreated and treated seeds with husk showed the same values in these nutrients even for minerals content. Hence, biochemical analyzes of cowpea seeds treated with the formulated insecticide showed no change in nutritional quality and M. charantia leaves extract in association with gum arabic/kaolinite composite could be used as insect repellent.

ABSTRACTDengue is often misclassified and underreported in Africa due to inaccurate differential diagnoses of nonspecific febrile illnesses such as malaria, sparsity of diagnostic testing and poor clinical and genomic surveillance. There are limited reports on the seroprevalence and genetic diversity of dengue virus (DENV) in humans and vectors in Nigeria. In this study, we investigated the epidemiology and genetic diversity of dengue in the rainforest region of Nigeria. We screened 515 febrile patients who tested negative for malaria and typhoid fever in three hospitals in Oyo and Ekiti States in southern Nigeria with a combination of anti-dengue IgG/IgM/NS1 rapid test kits and metagenomic sequencing. We found that approximately 28% of screened patients had previous DENV exposure, with the highest prevalence in persons over sixty. Approximately 8% of the patients showed evidence of recent or current infection, and 2.7% had acute infection. Following sequencing of sixty samples, we assembled twenty DENV-1 genomes (3 complete and 17 partial). We found that all assembled genomes belonged to DENV-1 genotype III. Our phylogenetic analyses showed evidence of prolonged cryptic circulation of divergent DENV lineages in Oyo state. We were unable to resolve the source of DENV in Nigeria owing to limited sequencing data from the region. However, our sequences clustered closely with sequences in Tanzania and sequences reported in Chinese with travel history to Tanzania in 2019. This may reflect the wider unsampled bidirectional transmission of DENV-1 in Africa, which strongly emphasizes the importance of genomic surveillance in monitoring ongoing DENV transmission in Africa.

IntroductionStudies on the organisation of care and the power dynamic between providers and patients with HIV in sub-Saharan Africa are rare. This study aims to describe the patient-provider relationship and explore the challenges to optimal and patient-centred care for HIV patients.MethodsThis was a qualitative exploratory descriptive study using in-depth individual interviews and focus group discussions. In total, 17 individual interviews and 5 focus group discussions were conducted. This was conducted in four urban health facilities in Conakry, the capital of Guinea. Three group of participants were included in this study namely patients with HIV; health providers including facilities and services managers; and psychosocial counsellors. Psychosocial counsellors provide emotional and psychosocial support to HIV patients. Their role in the organization care in Guinea is new and they contribute to strengthening adherence of patients with HIV to ARV treatment.ResultsPatients with HIV, health providers, and psychosocial counsellors have a positive perception of the patient-provider relationship. This relationship was characterized essentially by maintaining confidentiality of HIV status disclosure, caring attitudes towards patients (being available, adjusting locations for accessing ART, based on patients’ preferences), and participating in HIV patient’s social life. However, scolding and miscommunication about the interpretation of viral load tests were reported. The shortage of human resources, low salaries of health staff, poor infrastructure, and the financial burden borne by patients with HIV impede the implementation of optimal patient-centred care.ConclusionIntegrating psychosocial counsellors in HIV care organization, improving access to ARV, infrastructure, increasing human resources, and removing the financial burden for HIV patients are needed to optimal patient-centred care in Guinea.

It is currently unknown whether all Plasmodium falciparum-infected mosquitoes are equally infectious. We assessed sporogonic development using cultured gametocytes in the Netherlands and naturally circulating strains in Burkina Faso. We quantified the number of sporozoites expelled into artificial skin in relation to intact oocysts, ruptured oocysts, and residual salivary gland sporozoites. In laboratory conditions, higher total sporozoite burden was associated with shorter duration of sporogony (p

BackgroundApproximately 70% of Sub-Saharan African countries have experienced armed conflicts with significant battle-related fatalities in the past two decades. Niger has witnessed a substantial rise in conflict-affected populations in recent years. In response, international cooperation has aimed to support health transformation in Niger’s conflict zones and other conflict-affected areas in Sub-Saharan Africa. This study seeks to review the available evidence on health interventions facilitated by international cooperation in conflict zones, with a focus on Niger.MethodsWe conducted a systematic literature review (SLR) adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search was conducted from 2000 to 4 September 2022 using MeSH terms and keywords to identify relevant studies and reports in Sub-Saharan Africa and specifically in Niger. Databases such as PubMed (Medline), Google Scholar, Google, and gray literature were utilized. The findings were presented both narratively and through tables and a conceptual framework.ResultsOverall, 24 records (10 studies and 14 reports) that highlighted the significant role of international cooperation in promoting health transformation in conflict zones across Sub-Saharan Africa, including Niger, were identified. Major multilateral donors identified were the World Health Organization (WHO), United Nations Children’s Fund (UNICEF), United Nations Fund for Population Activities (UNFPA), World Bank, United States Agency for International Development (USAID), European Union, European Commission Humanitarian Aid (ECHO), Global Fund, and Global Alliance for Vaccines and Immunization (GAVI). Most supports targeted maternal, newborn, child, adolescent, and youth health, nutrition, and psycho-social services. Furthermore, interventions were in the form of public health initiatives, mobile clinic implementation, data management, human resource capacity building, health information systems, health logistics, and research funding in conflict zones.ConclusionThis literature review underscores the significant engagement of international cooperation in strengthening and transforming health services in conflict-affected areas across Sub-Saharan Africa, with a particular focus on Niger. However, to optimize the effectiveness of healthcare activities from short- and long-term perspectives, international partners and the Ministry of Public Health need to re-evaluate and reshape their approach to health intervention in conflict zones.

In Senegal, onions (Allium cepa L.) are an important and widely consumed crop. Several varieties and speculations are cultivated, with yields and bulbs qualities depending on technical itineraries and cultivation areas. The aim of this study is to evaluate the quality of onion bulbs produced at the Kalassane and Nguéthioro sites, using morphological and physicochemical parameters. To this end, an optimized treatment based on the “Société Nationale d’Aménagement et d’Exploitation des terres du Delta” (SAED) technical data sheet, requiring water and fertilizer inputs to be controlled (4455.4 m3 of water/ha, 9 kg/9 m2 of organic matter applied before sowing and 224 g/m2 of N- P-K applied in 4 inputs), another based on the farmers' method using excessive quantities of water and fertilizers (6526.1 m3 water/ha, 12 kg/9 m2 organic matter applied after sowing and 748 g/m2 N-P-K applied in 5 applications), and their combinations were applied on Kalassane. Next, the best method for ensuring quality bulbs at Kalassane was also tested at Nguéthioro. The results show that at Kalassane, onion bulbs from the optimized method are small (67.96 ± 14.40 g) and less waterlogged (Wc 85.44 % ± 0.71, aw 0.83 ± 0.01), with a high total polyphenol content (7.01 mg/100 g ± 0.01), in contrast to those from the farmers’ method, which are 100.80 g ± 14.22; 87.14 % ± 0.69; 0.91 ± 0.01 and 2.11 mg/100 g ± 0.01 respectively. In short, this study leads to the conclusion that optimized practice is the best treatment guaranteeing better quality. In addition, the optimized method showed a difference between the results for the two sites. In the future, repeating this experiment coupled with edaphic characteristics will enable us to determine the influence of soil on the physicochemical and nutritional quality of onions.

Abstract Background Dual hrp2/hrp3 genes deletions in P. falciparum isolates are increasingly reported in malaria-endemic countries and can produce false negative RDT results leading to inadequate case management. Data on the frequency of hrp2/hrp3 deleted parasites are rarely available and it has become necessary to investigate the issue in Burkina Faso. Methods Plasmodium falciparum-positive dried blood spots were collected during a cross-sectional household survey of the malaria asymptomatic children from Orodara, Gaoua, and Banfora. Amplicons from the target regions (exon 2 of hrp2 and hrp3 genes) were generated using multiplexed nested PCR and sequenced according to Illumina’s MiSeq protocol. Results A total of 251 microscopically positive parasite isolates were sequenced to detect hrp2 and hrp3 gene deletions. The proportion of RDTs negative cases among microscopy positive slides was 12.7% (32/251). The highest prevalence of negative RDTs was found in Orodara 14.3% (5/35), followed by Gaoua 13.1%(24/183), and Banfora 9.1% (3/33). The study found that 95.6% of the parasite isolates were wild type hrp2/ hrp3 while 4.4% (11/251) had a single hrp2 deletion. Of the 11 hrp2 deletion samples, 2 samples were RDT negative (mean parasitaemia was 83 parasites/ μL) while 9 samples were RDT positive with a mean parasitaemia of 520 parasites /μL (CI95%: 192–1239). The highest frequency of hrp2 deletion 4/35 (11.4%) was found in Orodara, while it was similar in the other two sites (

Abstract The role of climate in the Coronavirus disease 2019 (COVID-19) transmission appears to be controversial, as reported in earlier studies. In Africa, the subject is poorly documented. In this study, over the period from January 1st, 2020 to September 31, 2022, the daily variations in cumulative confirmed cases of COVID-19 for each African country (54 countries) are modelled through time-series-based approaches and using meteorological factors as covariates. It is suggested from the findings that climate plays a role in COVID-19 transmission since at least one meteorological factor is found to be significant in 32 countries. In decreasing order, the most often occurring meteorological factors are dewpoint temperature, relative and absolute humidity, average temperature and solar radiation. Most of these factors show a lagged effect with confirmed cases (between 0 and 28 days). Also, some meteorological factors exhibit contrasting effects on COVID-19 transmission, resulting in both positive and negative association with cumulative cases, therefore highlighting the complex nature of the interplay between climate and COVID-19 transmission.