Papers by WELLINGTON OYIBO
Micromachines, Apr 19, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Microbes, Infection and Chemotherapy
Background. Global response to malaria has stalled, despite increased malaria control efforts wor... more Background. Global response to malaria has stalled, despite increased malaria control efforts worldwide. Antibodies are among the immune factors that play a role in mediating protection in malaria, although the mechanism remain unclear. The study evaluated profile of total immunoglobulin G (IgG) and E (IgE) among malaria cases. Methods: A hospital based cross-sectional survey of individuals that presented with malaria symptoms and assessed diagnostic care at selected health facilities in Ikorodu Local Government Area (LGA) of Lagos State, Nigeria. Demographic information was recorded using structured questionnaire. Malaria diagnosis was done by microscopy, ELISA was used to evaluate plasma IgG and IgE profiles among malaria positive and control group. Data was analyzed using SPSS version 23. Results: LgE plasma level (34760.63±2954.5 pg/ml, p=0.005) was significantly higher in malaria positive cases compared with negative control group (19912.12± 6762.6pg/ml, p<0.01). In contrast...
Microbes, Infection and Chemotherapy
Background. Global response to malaria has stalled, despite increased malaria control efforts wor... more Background. Global response to malaria has stalled, despite increased malaria control efforts worldwide. Antibodies are among the immune factors that play a role in mediating protection in malaria, although the mechanism remain unclear. The study evaluated profile of total immunoglobulin G (IgG) and E (IgE) among malaria cases. Methods: A hospital based cross-sectional survey of individuals that presented with malaria symptoms and assessed diagnostic care at selected health facilities in Ikorodu Local Government Area (LGA) of Lagos State, Nigeria. Demographic information was recorded using structured questionnaire. Malaria diagnosis was done by microscopy, ELISA was used to evaluate plasma IgG and IgE profiles among malaria positive and control group. Data was analyzed using SPSS version 23. Results: LgE plasma level (34760.63±2954.5 pg/ml, p=0.005) was significantly higher in malaria positive cases compared with negative control group (19912.12± 6762.6pg/ml, p<0.01). In contrast...
Blood transfer devices for malaria rapid diagnostic tests: evaluation of accuracy,
Background: Microsporidia are obligate intracellular parasites that infect a broad range of verte... more Background: Microsporidia are obligate intracellular parasites that infect a broad range of vertebrates and invertebrates. They have been increasingly recognized as human pathogens in AIDS patients, mainly associated with a life-threatening chronic diarrhea and systemic disease. However, to date the global epidemiology of human microsporidiosis is poorly understood, and recent data suggest that the incidence of these pathogens is much higher than previously reported and may represent a neglected etiological agent of more common diseases indeed in immunocompetent individuals. To contribute to the knowledge of microsporidia molecular epidemiology in HIV-positive patients in Nigeria, the authors tested stool samples proceeding from patients with and without diarrhea. Methodology/Principal Findings: Stool samples from 193 HIV-positive patients with and without diarrhea (67 and 126 respectively) from Lagos (Nigeria) were investigated for the presence of microsporidia and Cryptosporidium ...
2020 IEEE Global Humanitarian Technology Conference (GHTC), 2020
We investigate the spin-polarized transport properties of a two-dimensional electron gas in a n-t... more We investigate the spin-polarized transport properties of a two-dimensional electron gas in a n-type diluted magnetic narrow gap semiconductor quantum well subjected to a perpendicular magnetic and electric field. Interesting beating patterns in the magneto resistance are found which can be tuned significantly by varying the electric field. A resonant enhancement of spin-polarized current is found which is induced by the competition between the s-d exchange interaction and the Rashba effect [Y. A. Bychkov and E. I. Rashba, J. Phys. C 17, 6039 (1984)].
Infectious Diseases of Poverty, 2019
Background: The development and spread of artemisinin-resistant Plasmodium falciparum malaria in ... more 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
Tropical Medicine & International Health, 2011
objectives This enquiry aimed to provide a snapshot of availability, price and quality of malaria... more objectives This enquiry aimed to provide a snapshot of availability, price and quality of malaria rapid diagnostic tests (RDTs) in private health facilities at selected sites in six malaria-endemic countries in Africa, South East Asia and South America. methods In each study site, data collectors surveyed private healthcare facilities which were selected based on accessibility from their home institution. Using a questionnaire, information was recorded about the facility itself and the malaria RDT(s) available. Where possible, a small number of RDTs were procured and quality control tested using a standardized procedure. results Of the 324 private healthcare facilities visited, 35 outlets (mainly private clinics and hospitals) were found to supply 10 different types of RDTs products. RDT prices across the six countries ranged from US$1.00 to $16.81. Five of the 14 malaria RDTs collected failed quality control testing. conclusions In the private outlets sampled, the availability of RDTs was limited. Some of the RDTs whose quality we tested demonstrated inadequate sensitivity. This presents a number of risks. Given the more widespread distribution of antimalarials currently planned for private sector facilities, parasitebased diagnosis in this sector will be essential to adhere to the WHO guidelines for effective case management of malaria. Considerable regulation and quality control are also necessary to assure the availability of accurate and reliable RDTs, as well as adequate case management and provider adherence to RDT results. Public sector engagement is likely to be essential in this process.
Malaria Journal, 2011
Background: Malaria rapid diagnostic tests (RDTs) are increasingly used by remote health personne... more Background: Malaria rapid diagnostic tests (RDTs) are increasingly used by remote health personnel with minimal training in laboratory techniques. RDTs must, therefore, be as simple, safe and reliable as possible. Transfer of blood from the patient to the RDT is critical to safety and accuracy, and poses a significant challenge to many users. Blood transfer devices were evaluated for accuracy and precision of volume transferred, safety and ease of use, to identify the most appropriate devices for use with RDTs in routine clinical care. Methods: Five devices, a loop, straw-pipette, calibrated pipette, glass capillary tube, and a new inverted cup device, were evaluated in Nigeria, the Philippines and Uganda. The 227 participating health workers used each device to transfer blood from a simulated finger-prick site to filter paper. For each transfer, the number of attempts required to collect and deposit blood and any spilling of blood during transfer were recorded. Perceptions of ease of use and safety of each device were recorded for each participant. Blood volume transferred was calculated from the area of blood spots deposited on filter paper. Results: The overall mean volumes transferred by devices differed significantly from the target volume of 5 microliters (p < 0.001). The inverted cup (4.6 microliters) most closely approximated the target volume. The glass capillary was excluded from volume analysis as the estimation method used is not compatible with this device. The calibrated pipette accounted for the largest proportion of blood exposures (23/225, 10%); exposures ranged from 2% to 6% for the other four devices. The inverted cup was considered easiest to use in blood collection (206/ 226, 91%); the straw-pipette and calibrated pipette were rated lowest (143/225 [64%] and 135/225 [60%] respectively). Overall, the inverted cup was the most preferred device (72%, 163/227), followed by the loop (61%, 138/227). Conclusions: The performance of blood transfer devices varied in this evaluation of accuracy, blood safety, ease of use, and user preference. The inverted cup design achieved the highest overall performance, while the loop also performed well. These findings have relevance for any point-of-care diagnostics that require blood sampling.
American Journal of Botany, 2012
Additional file 2:An example Field of View from the unreadable thin film, compared to an acceptab... more Additional file 2:An example Field of View from the unreadable thin film, compared to an acceptable FoV.
Multilingual abstracts in the five official working languages of the United Nations. (PDF 259 kb)
2019 IEEE Global Humanitarian Technology Conference (GHTC)
Schistosomiasis is a treatable and preventable neglected tropical disease of Public Health import... more Schistosomiasis is a treatable and preventable neglected tropical disease of Public Health importance affecting over 250 million people worldwide while Nigeria is one of the high burden countries. Currently available diagnoses are cumbersome, low in sensitivity and not field-adaptable given the high skill required that are not available in the rural settings where the diseases are majorly prevalent. Democratizing access to diagnosis with a rapid, easy-to-use, accurate diagnosis is critical in currently stepped-up control, pre-elimination and elimination strategies for urinary schistosomiasis. In this paper, we describe the design process of a low-cost smartphone-based microscope for rapid diagnosis of urinary Schistosomiasis. Field research conducted in Nigeria with the active involvement of key stakeholders in the research and development (R&D) process validated our assumptions and enabled the development of our proof-of-concept into a working prototype in three iterative designs steps. Through this design process, we investigated the local development of technical optics for good quality imaging and explored the simplification of sample preparation techniques using commonly available materials. Starting from the first iteration, the output of each design step was used as the input to the subsequent iterations to optimize our system design. Insightful results and input from the field demonstrated that an adaptive design approach was needed to facilitate the rapid development and deployment of point-of-care diagnostic devices for use in low-resource settings. It is our goal that these devices will be locally manufactured in Nigeria to expand access to the test given her huge population and high disease burden, quick repairs, and easy maintenance on the field.
Additional file 2: Figure S1. Assay optimization. (A) Serial dilutions of recombinant PfHRP2 type... more Additional file 2: Figure S1. Assay optimization. (A) Serial dilutions of recombinant PfHRP2 types A, B and C were assayed to determine the lowest concentration at which each antigen is detected; (B) P. falciparum Benin I and Borneo and P. vivax field isolates were assayed in a serial dilution fashion to assess differences between the analytical sensitivity for P. falciparum and P. vivax pLDH; (C) PfHRP2 and pLDH positive samples (plasma, cultured field isolates and recombinant proteins) were assayed in singleplex (X axes) and multiplex (Y axes).
Additional file 1: Text S1. Biotinylation of detection mAbs. Text S2. Bead suspension array proce... more Additional file 1: Text S1. Biotinylation of detection mAbs. Text S2. Bead suspension array procedure. Text S3. Singleplex versus Multiplex testing. Text S4. Preparation and extraction of proteins from dried blood spots.
Malaria and HIV co-infection and their effect on haemoglobin levels from three health-care instit... more Malaria and HIV co-infection and their effect on haemoglobin levels from three health-care institutions in Lagos, southwest Nigeria
Plasmodium nucleic acids have been detected in serum and plasma, but there is little published da... more Plasmodium nucleic acids have been detected in serum and plasma, but there is little published data describing the diagnostic performance of malaria nucleic acid amplification tests (NAATs) using these specimen types. Previously, our group described a multiplex NAAT for the detection of dengue virus, Leptospira, and Plasmodium species with a callout for P. falciparum (the DLM assay) that demonstrated sensitive detection of P. falciparum from plasma samples during initial evaluation. In this study, we evaluated the sensitivity and specificity of P. falciparum detection in febrile Nigerian patients using the DLM assay, microscopy, and a rapid diagnostic test (BinaxNOW Malaria). Assay performances were compared using a composite reference, which was considered positive if malaria was detected by two or more methods. Serum (n ؍ 182) or plasma (n ؍ 148) from 317 patients was tested; the average sample volume was 70 l (range, 5 to 300 l). The sensitivity and specificity of the DLM assay were 97.1% and 93.5%, respectively. The sensitivity of the malaria rapid diagnostic test (98.1%) was similar to that of the DLM assay, and both proved significantly more sensitive than microscopy (79%; P < 0.0001). When analysis was limited to samples with >75 l of serum or plasma, the sensitivity of the DLM assay improved to 99% and specificity was 97.5%. For P. falciparum cases, cycle threshold values in the DLM assay correlated with the parasite density detected by microscopy (Spearman's rank correlation coefficient, P < 0.0001). In conclusion, malaria detection using the DLM assay on serum or plasma is more sensitive than and equal in specificity to microscopy in patients with P. falciparum malaria.
Global sequence variation in the histidine-rich proteins 2 and 3 of Plasmodium falciparum: implic... more Global sequence variation in the histidine-rich proteins 2 and 3 of Plasmodium falciparum: implications for the performance of malaria rapid diagnostic tests
Cryptosporidium , a protozoan parasite that causes gastrointestinal illness, is transmitted by in... more Cryptosporidium , a protozoan parasite that causes gastrointestinal illness, is transmitted by ingestion of oocysts excreted in human or animal stools. Cryptosporidiosis presents with severe diarrhoea in HIV/AIDS patients and self-limiting in immunocompetent individuals. The parasite is yet to receive sufficient public health attention in Nigeria . This study was undertaken to investigate association of Cryptosporidium oocysts with other intestinal parasites in patients with gastrointestinal complaints. The collected stool samples were examined immediately with wet mount using saline solution and 5% lugol iodine. The aliquot was centrifuged in formal-ether using concentration technique, then stained with Kinyoun’s Carbol-fuchsin. Two hundred and thirty-eight (238) stool samples were collected from patients with diarrhoea and other gastrointestinal symptoms. Of the 238 participants, 20(8.4%) were HIV-seropositive patients. Cryptosporidium oocyst was identified using Kinyoun carbol fu...
Malaria is a life-threatening disease affecting millions. Microscopy-based assessment of thin blo... more Malaria is a life-threatening disease affecting millions. Microscopy-based assessment of thin blood films is a standard method to (i) determine malaria species and (ii) quantitate high-parasitemia infections. Full automation of malaria microscopy by machine learning (ML) is a challenging task because field-prepared slides vary widely in quality and presentation, and artifacts often heavily outnumber relatively rare parasites. In this work, we describe a complete, fully-automated framework for thin film malaria analysis that applies ML methods, including convolutional neural nets (CNNs), trained on a large and diverse dataset of field-prepared thin blood films. Quantitation and species identification results are close to sufficiently accurate for the concrete needs of drug resistance monitoring and clinical use-cases on field-prepared samples. We focus our methods and our performance metrics on the field use-case requirements. We discuss key issues and important metrics for the appli...
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Papers by WELLINGTON OYIBO