scholarly journals Further Evidence of Inadequate Quality in Lateral Flow Devices Commercially Offered for the Diagnosis of Rabies

2020 ◽  
Vol 5 (1) ◽  
pp. 13 ◽  
Author(s):  
Antonia Klein ◽  
Anna Fahrion ◽  
Stefan Finke ◽  
Marina Eyngor ◽  
Shiri Novak ◽  
...  

As a neglected zoonotic disease, rabies causes approximately 5.9 × 104 human deaths annually, primarily affecting low- and middle-income countries in Asia and Africa. In those regions, insufficient surveillance is hampering adequate medical intervention and is driving the vicious cycle of neglect. Where resources to provide laboratory disease confirmation are limited, there is a need for user-friendly and low-cost reliable diagnostic tools that do not rely on specialized laboratory facilities. Lateral flow devices (LFD) offer an alternative to conventional diagnostic methods and may strengthen control efforts in low-resource settings. Five different commercially available LFDs were compared in a multi-centered study with respect to their diagnostic sensitivity and their agreement with standard rabies diagnostic techniques. Our evaluation was conducted by several international reference laboratories using a broad panel of samples. The overall sensitivities ranged from 0% up to 62%, depending on the LFD manufacturer, with substantial variation between the different laboratories. Samples with high antigen content and high relative viral load tended to test positive more often in the Anigen/Bionote test, the latter being the one with the best performance. Still, the overall unsatisfactory findings corroborate a previous study and indicate a persistent lack of appropriate test validation and quality control. At present, the tested kits are not suitable for in-field use for rabies diagnosis, especially not for suspect animals where human contact has been identified, as an incorrect negative diagnosis may result in human casualties. This study points out the discrepancy between the enormous need for such a diagnostic tool on the one hand, and on the other hand, a number of already existing tests that are not yet ready for use.

Author(s):  
Andrea Springer ◽  
Antje Glass ◽  
Julia Probst ◽  
Christina Strube

AbstractAround the world, human health and animal health are closely linked in terms of the One Health concept by ticks acting as vectors for zoonotic pathogens. Animals do not only maintain tick cycles but can either be clinically affected by the same tick-borne pathogens as humans and/or play a role as reservoirs or sentinel pathogen hosts. However, the relevance of different tick-borne diseases (TBDs) may vary in human vs. veterinary medicine, which is consequently reflected by the availability of human vs. veterinary diagnostic tests. Yet, as TBDs gain importance in both fields and rare zoonotic pathogens, such as Babesia spp., are increasingly identified as causes of human disease, a One Health approach regarding development of new diagnostic tools may lead to synergistic benefits. This review gives an overview on zoonotic protozoan, bacterial and viral tick-borne pathogens worldwide, discusses commonly used diagnostic techniques for TBDs, and compares commercial availability of diagnostic tests for humans vs. domestic animals, using Germany as an example, with the aim of highlighting existing gaps and opportunities for collaboration in a One Health framework.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Minna M. D. Romano ◽  
Henrique T. Moreira ◽  
André Schmidt ◽  
Benedito Carlos Maciel ◽  
José Antônio Marin-Neto

Right ventricle (RV) is considered a neglected chamber in cardiology and knowledge about its role in cardiac function was mostly focused on ventricular interdependence. However, progress on the understanding of myocardium diseases primarily involving the RV led to a better comprehension of its role in health and disease. In Chagas disease (CD), there is direct evidence from both basic and clinical research of profound structural RV abnormalities. However, clinical detection of these abnormalities is hindered by technical limitations of imaging diagnostic tools. Echocardiography has been a widespread and low-cost option for the study of patients with CD but, when applied to the RV assessment, faces difficulties such as the absence of a geometrical shape to represent this cavity. More recently, the technique has evolved to a focused guided RV imaging and myocardial deformation analysis. Also, cardiac magnetic resonance (CMR) has been introduced as a gold standard method to evaluate RV cavity volumes. CMR advantages include precise quantitative analyses of both LV and RV volumes and its ability to perform myocardium tissue characterization to identify areas of scar and edema. Evolution of these cardiac diagnostic techniques opened a new path to explore the pathophysiology of RV dysfunction in CD.


2019 ◽  
Vol 4 (4) ◽  
pp. e001704 ◽  
Author(s):  
Saundria Moed ◽  
Muhammad H Zaman

Liver disease is a significant public health burden in both high-income and low-income countries, accounting for over 2 million annual, global deaths. Despite the significant mortality burden, liver diseases are historically a neglected problem due to a lack of accurate incidence and prevalence statistics, as well as national and international programmes targeting these diseases. A large portion of deaths due to liver diseases can be treated (eg, chronic hepatitis B), cured (eg, chronic hepatitis C) or prevented (eg, acute liver failure due to medications) if prompt diagnosis is made, but currently diagnostic methods fall short. Therefore, there is a critical need to fund the development of prompt, effective diagnostics for liver function, specifically in low-income and middle-income countries where the landscape for this testing is sparse. Here, we review and compare available and currently emerging diagnostic methods for liver injury in low-income and middle-income settings, while highlighting the opportunities and challenges that exist in the field.


Author(s):  
Rajshri Kundlik Satvekar

Early, rapid and ultrasensitive diagnosis of COVID-19 to facilitate high-throughput analysis without a high degree of technical expertise or sophisticated equipment is necessary to expand COVID-19 testing capability. Leveraging interdisciplinary proficiency in analytical chemistry, biomedical instrumentation, molecular biology, microfluidics, and nanotechnology, considerable advances have been made to develop a novel diagnostic tool that assures superior key performances for COVID-19 diagnosis. This review summarizes the nano-enabled systems such as electrochemical nanobiosensor for SARS-CoV-2 virus detection and emphasizes promising diagnostic techniques to extensively facilitate the diagnostic practices during the COVID-19 pandemic. Currently, three main diagnostic methods have been widely used in the COVID-19 pandemic: nucleic acid (NA)-based testing, computed tomography (CT), and serological testing. NA-based detection of SARS-CoV-2 such as Reverse transcription polymerase chain reaction has become the gold standard for COVID-19 diagnosis. This review congregates significant contributions in the electrochemical nanobiosensor research area, which is helpful for further nanobiosensor development. Although many efforts were taken to detect the SARS-CoV-2, the COVID 19 diagnosis still relies on expensive prolonged analysis. A rapid and reliable alternative is the utilization of a low-cost nanobiosensor for SARS-CoV-2 detection that can rapidly diagnose the disease even in asymptomatic conditions with high reliability and sensitivity.


2019 ◽  
Vol 5 (4) ◽  
pp. 90 ◽  
Author(s):  
Amir Arastehfar ◽  
Brian L. Wickes ◽  
Macit Ilkit ◽  
David H. Pincus ◽  
Farnaz Daneshnia ◽  
...  

Extensive advances in technology offer a vast variety of diagnostic methods that save time and costs, but identification of fungal species causing human infections remains challenging in developing countries. Since the echinocandins, antifungals widely used to treat invasive mycoses, are still unavailable in developing countries where a considerable number of problematic fungal species are present, rapid and reliable identification is of paramount importance. Unaffordability, large footprints, lack of skilled personnel, and high costs associated with maintenance and infrastructure are the main factors precluding the establishment of high-precision technologies that can replace inexpensive yet time-consuming and inaccurate phenotypic methods. In addition, point-of-care lateral flow assay tests are available for the diagnosis of Aspergillus and Cryptococcus and are highly relevant for developing countries. An Aspergillus galactomannan lateral flow assay is also now available. Real-time PCR remains difficult to standardize and is not widespread in countries with limited resources. Isothermal and conventional PCR-based amplification assays may be alternative solutions. The combination of real-time PCR and serological assays can significantly increase diagnostic efficiency. However, this approach is too expensive for medical institutions in developing countries. Further advances in next-generation sequencing and other innovative technologies such as clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostic tools may lead to efficient, alternate methods that can be used in point-of-care assays, which may supplement or replace some of the current technologies and improve the diagnostics of fungal infections in developing countries.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2362
Author(s):  
Lucia Napione

The goal of personalized medicine is to target the right treatments to the right patients at the right time. Patients with a variety of cancers and other complex diseases are regularly tested as part of patient care, enabling physicians to personalize patient monitoring and treatment. Among the sought-after diagnostic tools, there is an increasing interest and need for those based on a low-cost, easy, rapid, and accurate method for the detection of specific circulating biomarkers above a detection threshold. Lateral flow tests (LFTs), enhanced by nanotechnology, can fulfil these requirements, providing a significant support to personalized patient monitoring. In this review, after a short historical synopsis of membrane-based lateral flow assays, including a description of a typical configuration of a LFT strip, a careful collection is presented of the best characterized nanotechnology approaches previously reported for the enhancement of target detection performance. The attempt is to offer an overview of currently integrated nanotechnologies in LFTs, fostering the actual future development of advantageous diagnostic devices for patient monitoring.


2020 ◽  
Vol 33 (6) ◽  
pp. 466-484 ◽  
Author(s):  
Francisco Javier Candel ◽  
Pablo Barreiro ◽  
Jesús San Román ◽  
Juan Carlos Abanades ◽  
Raquel Barba ◽  
...  

The high transmissibility of SARS-CoV-2 before and shortly after the onset of symptoms suggests that only diagnosing and isolating symptomatic patients may not be sufficient to interrupt the spread of infection; therefore, public health measures such as personal distancing are also necessary. Additionally, it will be important to detect the newly infected individuals who remain asymptomatic, which may account for 50% or more of the cases. Molecular techniques are the “gold standard” for the diagnosis of SARS-CoV-2 infection. However, the massive use of these techniques has generated some problems. On the one hand, the scarcity of resources (analyzers, fungibles and reagents), and on the other the delay in the notification of results. These two facts translate into a lag in the application of isolation measures among cases and contacts, which favors the spread of the infection. Antigen detection tests are also direct diagnostic methods, with the advantage of obtaining the result in a few minutes and at the very “pointof-care”. Furthermore, the simplicity and low cost of these tests allow them to be repeated on successive days in certain clinical settings. The sensitivity of antigen tests is generally lower than that of nucleic acid tests, although their specificity is comparable. Antigenic tests have been shown to be more valid in the days around the onset of symptoms, when the viral load in the nasopharynx is higher. Having a rapid and real-time viral detection assay such as the antigen test has been shown to be more useful to control the spread of the infection than more sensitive tests, but with greater cost and response time, such as in case of molecular tests. The main health institutions such as the WHO, the CDC and the Ministry of Health of the Government of Spain propose the use of antigenic tests in a wide variety of strategies to respond to the pandemic. This document aims to support physicians involved in the care of patients with suspected SC2 infection, in the context of a growing incidence in Spain since September 2020, which already represents the second pandemic wave of COVID-19.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Timothy S. Mamba ◽  
Cecilia K. Mbae ◽  
Johnson Kinyua ◽  
Erastus Mulinge ◽  
Gitonga Nkanata Mburugu ◽  
...  

Background. Cryptosporidiumis a protozoan parasite and a major cause of diarrhea in children and immunocompromised patients. Current diagnostic methods for cryptosporidiosis such as microscopy have low sensitivity while techniques such as PCR indicate higher sensitivity levels but are seldom used in developing countries due to their associated cost. A loop-mediated isothermal amplification (LAMP) technique, a method with shorter time to result and with equal or higher sensitivity compared to PCR, has been developed and applied in the detection ofCryptosporidiumspecies. The test has a detection limit of 10 pg/µl (~100 oocysts/ml) indicating a need for more sensitive diagnostic tools. This study developed a more sensitive lateral flow dipstick (LFD) LAMP test based on SAM-1 gene and with the addition of a second set of reaction accelerating primers (stem primers).Results. The stem LFD LAMP test showed analytical sensitivity of 10 oocysts/ml compared to 100 oocysts/ml (10 pg/ul) for each of the SAM-1 LAMP test and nested PCR. The stem LFD LAMP and nested PCR detected 29/39 and 25/39 positive samples of previously identifiedC. parvumandC. hominisDNA, respectively. The SAM-1 LAMP detected 27/39. On detection ofCryptosporidiumDNA in 67 clinical samples, the stem LFD LAMP detected 16 samples and SAM-2 LAMP 14 and nested PCR identified 11. Preheating the templates increased detection by stem LFD LAMP to 19 samples. Time to results from master mix preparation step took ~80 minutes. The test was specific, and no cross-amplification was recorded with nontarget DNA.Conclusion.The developed stem LFD LAMP test is an appropriate method for the detection ofC. hominis, C. parvum,andC. meleagridisDNA in human stool samples. It can be used in algorithm with other diagnostic tests and may offer promise as an effective diagnostic tool in the control of cryptosporidiosis.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Maxwell W. Waema ◽  
Gerald Misinzo ◽  
John M. Kagira ◽  
Eric L. Agola ◽  
Helena A. Ngowi

Porcine cysticercosis is a neglected and underestimated disease caused by metacestode stage of the tapeworm, Taenia solium (T. solium). Pigs are the intermediate hosts of T. solium while human are the only known definitive host. The disease has an economic consequence because the affected farmers lose 50−100 percent of the value of pigs if they are infected. Lack of affordable, easy to use, sensitive, and specific molecular diagnostic tools for detection of infections at the farm level hinders the control of porcine cysticercosis in endemic areas. A number of DNA based diagnostic assays for the detection of T. solium infections in pigs have been developed and evaluated but none is applicable at low-resource areas where this disease is an endemic. This review focuses mainly on DNA based diagnostic methods, their sensitivity, specificity, and utilization at low-resource areas. We summarized data from 65 studies on the current DNA-detection based diagnostic techniques for T. solium cysticercosis in porcine, published in English between the years 2000–2018, identified through PubMed search engine. Of the different polymerase chain reaction (PCR) assays developed for identification of T. solium, the most sensitive (97−100%) and specific (100%) one is nested PCR. One study utilized loop-mediated isothermal amplification (LAMP) as a diagnostic tool for the detection of T. solium infections though its field use was never determined. Recombinase polymerase amplification (RPA) has been evaluated as a diagnostic tool for a variety of diseases, but has never been exploited for the diagnosis of cysticercosis/taeniasis. In conclusion, several molecular methods have been developed and evaluated in lab settings. However, there is need to validate these methods as a diagnostic tool to diagnose porcine cysticercosis in low-resource areas.


Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 41
Author(s):  
Yangji Xue ◽  
Qingming Kong ◽  
Haojie Ding ◽  
Chengzuo Xie ◽  
Bin Zheng ◽  
...  

Toxoplasma gondii is an obligate intracellular protozoan parasite that causes toxoplasmosis and threatens warm-blooded animal and human health worldwide. Simple and applicable diagnostic methods are urgently needed to guide development of effective approaches for prevention of toxoplasmosis. Most molecular diagnostic tools for T. gondii infection require high technical skills, sophisticated equipment, and a controlled lab environment. In this study, we developed a loop-mediated isothermal amplification-lateral-flow-dipstick (LAMP-LFD) assay that specifically targets the 529 bp for detecting T. gondii infection. This novel portable device is universal, fast, user-friendly, and guarantees experimental sensitivity as well as low risk of aerosol contamination. Our LAMP-LFD assay has a detection limit of 1 fg of T. gondii DNA, and shows no cross-reaction with other parasitic pathogens, including Cryptosporidium parvum, Leishmania donovani, and Plasmodium vivax. We validated the developed assay by detecting T. gondii in DNA extracted from blood samples collected from 318 stray cats and dogs sampled from Deqing, Wenzhou, Yiwu, Lishui and Zhoushan cities across Zhejiang province, Eastern China. The LAMP-LFD device detected T. gondii DNA in 4.76 and 4.69% of stray cats and dogs, respectively. In conclusion, the developed LAMP-LFD assay is efficient, minimizes aerosol contamination, and is therefore suitable for detecting T. gondii across basic medical institutions and field settings.


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