19 research outputs found

    Comparative performance of four rapid Ebola antigen-detection lateral flow immunoassays during the 2014-2016 Ebola epidemic in West Africa

    No full text
    BACKGROUND: Without an effective vaccine, as was the case early in the 2014-2016 Ebola Outbreak in West Africa, disease control depends entirely on interrupting transmission through early disease detection and prompt patient isolation. Lateral Flow Immunoassays (LFI) are a potential supplement to centralized reference laboratory testing for the early diagnosis of Ebola Virus Disease (EVD). The goal of this study was to assess the performance of commercially available simple and rapid antigen detection LFIs, submitted for review to the WHO via the Emergency Use Assessment and Listing procedure. The study was performed in an Ebola Treatment Centre laboratory involved in EVD testing in Sierra Leone. In light of the current Ebola outbreak in May 2018 in the Democratic Republic of Congo, which highlights the lack of clarity in the global health community about appropriate Ebola diagnostics, our findings are increasingly critical. METHODS: A cross-sectional study was conducted to assess comparative performance of four LFIs for detecting EVD. LFIs were assessed against the same 328 plasma samples and 100 whole EDTA blood samples, using the altona RealStar Filovirus Screen real-time RT-PCR as the bench mark assay. The performance of the Public Health England (PHE) in-house Zaire ebolavirus-specific real time RT-PCR Trombley assay was concurrently assessed. Statistical analysis using generalized estimating equations was conducted to compare LFI performance. FINDINGS: Sensitivity and specificity varied between the LFIs, with specificity found to be significantly higher for whole EDTA blood samples compared to plasma samples in at least 2 LFIs (P≤0.003). Using the altona RT-PCR assay as the bench mark, sensitivities on plasma samples ranged from 79.53% (101/127, 95% CI: 71.46-86.17%) for the DEDIATEST EBOLA (SD Biosensor) to 98.43% (125/127, 95% CI: 94.43-99.81%) for the One step Ebola test (Intec). Specificities ranged from 80.20% (158/197, 95% CI: 74.07-88.60%) for plasma samples using the ReEBOV Antigen test Kit (Corgenix) to 100.00% (98/98, 95% CI: 96.31-100.00%) for whole blood samples using the DEDIATEST EBOLA (SD Biosensor) and SD Ebola Zaire Ag (SD Biosensor). Results also showed the Trombley RT-PCR assay had a lower limit of detection than the altona assay, with some LFIs having higher sensitivity than the altona assay when the Trombley assay was the bench mark. INTERPRETATION: All of the tested EVD LFIs may be considered suitable for use in an outbreak situation (i.e. rule out testing in communities), although they had variable performance characteristics, with none possessing both high sensitivity and specificity. The non-commercial Trombley Zaire ebolavirus RT-PCR assay warrants further investigation, as it appeared more sensitive than the current gold standard, the altona Filovirus Screen RT-PCR assay.</p

    A study into the characteristics of gomuti (Arenga pinnata) fibre for usage as natural fibre composites

    No full text
    Gomuti is a natural fibre obtained from Arenga pinnata tree. In its native countries, the fibre has been used as roof, rope, insulation and water filter. This paper presents a study into the physical, mechanical and thermal characteristics of gomuti fibre to observe its viability as natural fibre composite material. The study includes observations of fibre morphology, diameter, density, single fibre tensile testing and observation of fibre thermal stability. It was found that diameter of the studied gomuti fibre was in a range of 81–313 mm, with an average of 168 mm. Density of gomuti was �1.40 g/cm3. The average strength of single gomuti fibre was 173.9 MPa and the average modulus of elasticity was 3847 MPa. Alkali treatment with sodium hydroxide was conducted to evaluate modifications in the fibre's characteristics. The treated gomuti fibres show altered diameter range, density, single fibre tensile properties and different thermogravimetric plots. Based on the results, gomuti fibre can be considered viable to be developed into natural fibre composites

    A review on the characteristics of gomuti fibre and its composites with thermoset resins

    No full text
    Gomuti fibre is obtained from Arenga pinnata tree and is known with other names such as sugar-palm fibre, gomutu, ijuk, serat aren and black fibre. This article presents a review on the physical, mechanical, chemical and thermal properties of gomuti fibre in comparison with other common natural fibres. Furthermore, this article reviews the mechanical properties of gomuti fibre composites with thermoset polymer resins based on the existing published literature. It is observable that gomuti fibre has a close similarity to coir fibre in its physical and mechanical properties than the other natural fibres. It has the characteristics of lower density, strength and modulus, but higher elongation. The composites with gomuti fibre also exhibit properties similar to coir fibre composites
    corecore