Publications by authors named "Wellington Oyibo"

Traditionally, automated slide scanning involves capturing a rectangular grid of field-of-view (FoV) images which can be stitched together to create whole slide images, while the autofocusing algorithm captures a focal stack of images to determine the best in-focus image. However, these methods can be time-consuming due to the need for X-, Y- and Z-axis movements of the digital microscope while capturing multiple FoV images. In this paper, we propose a solution to minimise these redundancies by presenting an optimal procedure for automated slide scanning of circular membrane filters on a glass slide.

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Purpose: Automated diagnosis of urogenital schistosomiasis using digital microscopy images of urine slides is an essential step toward the elimination of schistosomiasis as a disease of public health concern in Sub-Saharan African countries. We create a robust image dataset of urine samples obtained from field settings and develop a two-stage diagnosis framework for urogenital schistosomiasis.

Approach: Urine samples obtained from field settings were captured using the Schistoscope device, and eggs present in the images were manually annotated by experts to create the SH dataset.

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COVAX, the international initiative supporting COVID-19 vaccination campaigns globally, is budgeted to be the costliest public health initiative in low- and middle-income countries, with over 16 billion US dollars already committed. While some claim that the target of vaccinating 70% of people worldwide is justified on equity grounds, we argue that this rationale is wrong for two reasons. First, mass COVID-19 vaccination campaigns do not meet standard public health requirements for clear expected benefit, based on costs, disease burden and intervention effectiveness.

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We describe the MalariaGEN Pf7 data resource, the seventh release of genome variation data from the MalariaGEN network.  It comprises over 20,000 samples from 82 partner studies in 33 countries, including several malaria endemic regions that were previously underrepresented.  For the first time we include dried blood spot samples that were sequenced after selective whole genome amplification, necessitating new methods to genotype copy number variations.

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With global progress towards malaria reduction stalling, further analysis of epidemiology is required, particularly in countries with the highest burden. National surveys have mostly analysed infection prevalence, while large-scale data on parasite density and different developmental forms rarely available. In Nigeria, the country with the largest burden globally, blood slide microscopy of children up to 5 years of age was conducted in the 2018 National Demographic and Health Survey, and parasite prevalence previously reported.

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Article Synopsis
  • Conventional microscopy is the traditional method for diagnosing schistosomiasis but has limitations like low sensitivity and a high chance of errors.
  • The study evaluated the performance of the Schistoscope 5.0, which uses semi- and fully automated digital microscopy to detect Schistosoma haematobium eggs in urine, finding similar sensitivity between the two methods but significant differences in specificity.
  • Overall, the semiautomated version showed excellent correlation with conventional methods and a reliable performance in monitoring infection, though improvements are still needed for the fully automated AI component.
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Discovering and developing the desired antimalarials continue to be a necessity especially due to treatment failures, drug resistance, limited availability and affordability of antimalarial drugs and costs especially in poor malarial endemic countries. This study investigated the efficacies of two plant cocktails; CtA and CtB, selected based on their traditional usage. Efficacies of the cocktail extracts, chloroquine and pyrimethamine against were evaluated in mice using the suppressive, curative and prophylactic test models, after oral and intraperitoneal acute toxicity determination of the plant cocktails in accordance with Lorke's method.

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For many parasitic diseases, the microscopic examination of clinical samples such as urine and stool still serves as the diagnostic reference standard, primarily because microscopes are accessible and cost-effective. However, conventional microscopy is laborious, requires highly skilled personnel, and is highly subjective. Requirements for skilled operators, coupled with the cost and maintenance needs of the microscopes, which is hardly done in endemic countries, presents grossly limited access to the diagnosis of parasitic diseases in resource-limited settings.

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Ethnopharmacological Relevance: Malaria remains one of the most prevalent infectious diseases in tropical regions of the world, particularly in sub-Saharan Africa, where it remains epidemiologically holoendemic. The absence of effective vaccines and Plasmodium resistance to antimalarial drugs have been the major challenges to malaria control measures. An alternative strategy could be the application of validated and standardized herbal formulations.

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Introduction: Global progress in reducing malaria has stalled since 2015. Analysis of the situation is particularly needed in Nigeria, the country with by far the largest share of the burden, where approximately a quarter of all cases in the world are estimated to occur.

Methods: We analysed data from three nationwide surveys (Malaria Indicator Surveys in 2010 and 2015 and a National Demographic and Health Survey in 2018), with malaria parasite prevalence in children under 5 years of age determined by sampling from all 36 states of Nigeria, and blood slide microscopy performed in the same accredited laboratory for all samples.

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Background: Manual microscopy remains a widely-used tool for malaria diagnosis and clinical studies, but it has inconsistent quality in the field due to variability in training and field practices. Automated diagnostic systems based on machine learning hold promise to improve quality and reproducibility of field microscopy. The World Health Organization (WHO) has designed a 55-slide set (WHO 55) for their External Competence Assessment of Malaria Microscopists (ECAMM) programme, which can also serve as a valuable benchmark for automated systems.

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Background: Plasmodium falciparum-resistance to sulphadoxine-pyrimethamine (SP) has been largely reported among pregnant women. However, the profile of resistance markers to SP dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) in the general population are varied and not frequently monitored. Currently, SP is used as partner drug for artemisinin combination therapy (SP-artesunate) in some sub-Saharan African countries or as a prophylactic drug in intermittent preventive treatment of malaria during pregnancy and infants and in seasonal malaria chemoprevention (SMC).

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Article Synopsis
  • The study developed a new quantitative suspension array technology (qSAT) for detecting malaria antigens PfHRP2 and pLDH in various biological samples from people in malaria-endemic countries.
  • The qSAT showed high specificity and analytical ranges for detecting these antigens, with PfHRP2 showing better sensitivity than P. vivax LDH; both were correlated with parasite densities measured by different methods.
  • This new assay can serve as a reference for malaria diagnostic tests, help in validating rapid diagnostic tests, and assist in evaluating malaria prevalence in affected regions.
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Article Synopsis
  • * The program tested 332 RDT products against Plasmodium falciparum and Plasmodium vivax, utilizing measures like panel detection score, false positive rate, and invalid rate, resulting in an increase of products meeting performance criteria from 26.8% to 79.4% over multiple testing rounds.
  • * This independent evaluation improved transparency in the market, allowing healthcare providers to make informed decisions on malaria diagnosis and treatment, ultimately leading to a greater acceptance of RDTs in case management
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Background: Plasmodium falciparum, the deadliest causative agent of malaria, has high prevalence in Nigeria. Drug resistance causing failure of previously effective drugs has compromised anti-malarial treatment. On this basis, there is need for a proactive surveillance for resistance markers to the currently recommended artemisinin-based combination therapy (ACT), for early detection of resistance before it become widespread.

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Background: The development and spread of artemisinin-resistant Plasmodium falciparum malaria in Greater Mekong Subregion has created impetus for continuing global monitoring of efficacy of artemisinin-based combination therapies (ACTs). This post analyses is aimed to evaluate changes in early treatment response markers 10 years after the adoption of ACTs as first-line treatments of uncomplicated falciparum malaria in Nigeria.

Methods: At 14 sentinel sites in six geographical areas of Nigeria, we evaluated treatment responses in 1341 children under 5 years and in additional 360 children under 16 years with uncomplicated malaria enrolled in randomized trials of artemether-lumefantrine versus artesunate-amodiaquine at 5-year interval in 2009-2010 and 2014-2015 and at 2-year interval in 2009-2010 and 2012-2015, respectively after deployment in 2005.

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Objective: To assess polymorphism in Kelch 13 gene of Plasmodium falciparum isolates in Lagos, Nigeria.

Methods: 195 Plasmodium falciparum-positive dried blood spots collected from individuals that accessed diagnostic care at some health facilities and during community surveys across several Local Government Areas of Lagos State, Nigeria, were investigated for the presence of mutations in the K13 gene by nested polymerase chain reaction (PCR) using haplotype-specific probes and sequencing.

Results: Three mutant genotypes of K13 gene were observed: A578S in 0.

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Despite global efforts aimed at its elimination, malaria is still a significant health concern in many countries across the world. The disease is caused by blood-borne parasites, Plasmodium species, and is transmitted by female Anopheles mosquitoes and presents with generic febrile symptoms that are challenging to diagnose clinically. To adequately tackle this issue, an effective detection method is required for screening potential malaria patients for infection.

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The artemisinin-based combined therapy (ACT) post-treatment illness in -endemic areas is characterized by vague malaria-like symptoms. The roles of treatment modality, persistence of parasites and host proinflammatory response in disease course are unknown. We investigated the hypothesis that ACT post-treatment syndrome is driven by parasite genetic polymorphisms and proinflammatory response to persisting mutant parasites.

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The efficacies of 3-day regimens of artemether-lumefantrine (AL), artesunate-amodiaquine (AA), and dihydroartemisinin-piperaquine (DHP) were evaluated in 910 children < 5 years old with uncomplicated malaria from six geographical areas of Nigeria. Parasite positivity 1 day and Kaplan-Meier estimated risk of persistent parasitemia 3 days after therapy initiation were both significantly higher, and geometric mean parasite reduction ratio 1 day after treatment initiation (PRRD1) was significantly lower in AL-treated children than in AA- and DHP-treated children. No history of fever, temperature > 38°C, enrollment parasitemia > 75,000 μL, and PRRD1 < 5,000 independently predicted persistent parasitemia 1 day after treatment initiation.

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Background: Prompt and effective case detection and treatment are vital components of the malaria case management strategy as malaria-endemic countries implement the testing, treating and tracking policy. The implementation of this policy in public and formal private sectors continue to receive great attention while the informal private retail sector (mostly the patent and propriety medicine vendors [PPMVs]) where about 60% of patients with fever in Nigeria seek treatment is yet to be fully integrated. The PPMVs sell artemisinin combination therapies (ACTs) without prior testing and are highly patronized.

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Background And Objectives: Sick neonates in malaria endemic areas are frequently transfused with donor blood unscreened for malaria parasite. Consequently, they are at risk of transfusional malaria which can lead to increased neonatal mortality. The study aimed to determine the burden of transfusional malaria in neonates to help in policy formulation on prevention of transfusional malaria.

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Article Synopsis
  • Malaria rapid diagnostic tests (RDTs) are increasingly used in community health settings, but many users struggle with the blood transfer step, prompting a study on the effectiveness of an inverted cup device versus a traditional pipette.
  • The study assessed the volume accuracy and usability of an inverted cup device made from low-cost plastic (SBC) and compared it to a more expensive material (PMMA) using blood samples transferred by health workers in Nigeria.
  • Results indicated that the SBC device was more accurate in delivering blood volume and was preferred by health workers for its ease of use, with 96% successfully collecting blood and many finding it very user-friendly and suitable for routine use.
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Background: Artemisinin-based combination therapies (ACTs) have remained efficacious treatments of acute falciparum malaria in many endemic areas but there is little evaluation of factors contributing to the anaemia of acute falciparum malaria following long term adoption of ACTs as first-line antimalarials in African children.

Methods: Malarious <5 year-olds randomized to artemether-lumefantrine, artesunate-amodiaquine or dihydroartemisinin-piperaquine treatments were followed up clinically for 6 weeks. Anaemia was defined as haematocrit <30%; Malaria-attributable fall in haematocrit (MAFH) as the difference between haematocrit 28-42 days post- and pre-treatment; Total MAFH (TMAFH) as the difference between days 28-42 haematocrit and the lowest haematocrit recorded in the first week post-treatment initiation; Drug-attributable fall in haematocrit (DAFH) as the difference between MAFH and TMAFH; Early appearing anaemia (EAA) as haematocrit <30% occurring within 1 week in children with normal haematocrit pre-treatment.

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Autism Spectrum Disorder (ASD) is a globally prevalent neurodevelopmental disorder for which early diagnosis and intervention is the mainstay of management. In the African continent, limited data is available regarding the non-clinic based samples. Lack of information available to caregivers and inadequate skilled manpower often limit early detection and access to the few available though under resourced services in the community.

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