scholarly journals Minute-scale detection of SARS-CoV-2 using a low-cost biosensor composed of pencil graphite electrodes

2021 ◽  
Vol 118 (30) ◽  
pp. e2106724118
Author(s):  
Lucas F. de Lima ◽  
André L. Ferreira ◽  
Marcelo D. T. Torres ◽  
William R. de Araujo ◽  
Cesar de la Fuente-Nunez
Keyword(s):  
Low Income ◽  
High Frequency ◽  
Limit Of Detection ◽  
Low Cost ◽  
Cross Reactivity ◽  
Low Income Countries ◽  
Graphite Electrodes ◽  
Resource Limited ◽  
Do It Yourself ◽  
Scale Detection

COVID-19 has led to over 3.47 million deaths worldwide and continues to devastate primarily middle- and low-income countries. High-frequency testing has been proposed as a potential solution to prevent outbreaks. However, current tests are not sufficiently low-cost, rapid, or scalable to enable broad COVID-19 testing. Here, we describe LEAD (Low-cost Electrochemical Advanced Diagnostic), a diagnostic test that detects severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within 6.5 min and costs $1.50 per unit to produce using easily accessible and commercially available materials. LEAD is highly sensitive toward SARS-CoV-2 spike protein (limit of detection = 229 fg⋅mL−1) and displays an excellent performance profile using clinical saliva (100.0% sensitivity, 100.0% specificity, and 100.0% accuracy) and nasopharyngeal/oropharyngeal (88.7% sensitivity, 86.0% specificity, and 87.4% accuracy) samples. No cross-reactivity was detected with other coronavirus or influenza strains. Importantly, LEAD also successfully diagnosed the highly contagious SARS-CoV-2 B.1.1.7 UK variant. The device presents high reproducibility under all conditions tested and preserves its original sensitivity for 5 d when stored at 4 °C in phosphate-buffered saline. Our low-cost and do-it-yourself technology opens new avenues to facilitate high-frequency testing and access to much-needed diagnostic tests in resource-limited settings and low-income communities.

3D Printing of Microfluidics for Point of Care Diagnosis

2017 ◽  
Author(s):  
John P. Sibbitt ◽  
Mei He
Keyword(s):  
3D Printing ◽  
Low Income ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Disease Diagnosis ◽  
Low Income Countries ◽  
3D Design ◽  
Resource Limited ◽  
Production Techniques

Microfluidic lab-on-a-chip (MLOC) technology is a promising approach for point-of-care (POC) diagnosis; low reagent consumption, high sensitivity and quick analysis time are the most prominent benefits. However, microfabrication of MLOCs utilizes specialized techniques and infrastructure, making conventional fabrication time consuming and difficult. While relatively inexpensive production techniques exist for POC diagnoses, such as replication of polymer-based (e.g., PDMS) microfluidic POC devices on lithographic molds, this approach has limitations including: further hydrophilic surface modifications of PDMS, inability to change lithographic mold Z dimensions, and slow prototyping. In contrast, stereo-lithographical (SLA) printing can integrate all of the necessary fabrication resources in one instrument, allowing highly versatile microfluidic devices to be made at low cost. In this paper, we report two microfabrication approaches of microfluidics utilizing (SLA) 3D printing technology: I) Direct SLA printing of channels and structures of a monolithic microfluidic POC device; II) Indirect fabrication, utilizing SLA 3D printed molds for PDMS based microfluidic device replication. Additionally, we discuss previous work providing a proof of concept of applications in POC diagnosis, using direct 3D printing fabrication (approach I). The robustness and simplicity of these protocols allow integrating 3D design and microfabrication with smartphone-based disease diagnosis as a stand-alone system, offering strong adaptability for establishing diagnostic capacity in resource-limited areas and low-income countries.

scholarly journals 590Online + In-person: A Model for the Instruction of Contemporary Epidemiologic Methods in Resource-Limited Settings

2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Vivian Avelino-silva ◽  
Aggrey Semeere ◽  
Miriam Laker-Oketta ◽  
Helen Byakwaga ◽  
Mark Pletcher ◽  
...  
Keyword(s):  
Small Group ◽  
Low Income ◽  
Epidemiologic Methods ◽  
Low Cost ◽  
Group Discussion ◽  
Low Income Countries ◽  
Resource Limited Settings ◽  
Resource Limited ◽  
High Level ◽  
The U.S

Abstract Focus of Presentation Many low-income countries cannot support faculty to develop contemporary graduate-level courses in epidemiology and biostatistics. There are also insufficient resources to support all students who are interested in traveling abroad to study in resource-rich settings. To address this, we describe our experience with training a few students from resource-limited countries in the U.S. who have subsequently returned to their home countries and became instructors in a novel online plus in-person teaching model. Findings Most courses at our major U.S. training program in epidemiology videotape lectures for viewing on one’s own and post all other materials (e.g., homework) on the course’s website. The weekly learning cycle culminates with an in-person high-level small group discussion, led by a faculty member who facilitates 10-15 students. For the past 5 years, non-U.S. scholars from Africa and South America who have taken our courses in the U.S. have travelled back to their countries and become small group leaders for our courses. Identical to U.S. students, the students in these international venues view videotaped lectures, access other materials online, and have weekly in-person small group discussions. These international students represent another concurrent small group for the U.S-based course; they have identical access and evaluation. Conclusions By pairing online resources from a resource-rich setting with local in-person instruction, we provide students in resource-limited settings access to contemporary instruction in epidemiology at very low cost. Key messages Online plus local in-person teaching is a feasible model for providing instruction regarding epidemiologic methods in resource-limited settings.

scholarly journals Are Nanobiosensors an Improved Solution for Diagnosis of Leishmania?

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 491
Author(s):  
Sona Jain ◽  
Wanessa Santana ◽  
Silvio S. Dolabella ◽  
André L. S. Santos ◽  
Eliana B. Souto ◽  
...  
Keyword(s):  
Low Income ◽  
Neglected Tropical Diseases ◽  
Diagnostic Techniques ◽  
Cross Reactivity ◽  
Low Income Countries ◽  
Future Research ◽  
Immunological Tests ◽  
Diagnostic Approaches ◽  
Signal Improvement ◽  
Adequate Management

Leishmaniasis is one of the deadliest neglected tropical diseases affecting 12–15 million people worldwide, especially in middle- and low-income countries. Rapid and accurate diagnosis of the disease is important for its adequate management and treatment. Several techniques are available for the diagnosis of leishmaniasis. Among these, parasitological and immunological tests are most widely used. However, in most cases, the utilized diagnostic techniques are not good enough, showing cross-reactivity and reduced accuracy. In recent years, many new methods have been reported with potential for improved diagnosis. This review focuses on the diagnosis of Leishmania exploring the biosensors and nanotechnology-based options for their detection. New developments including the use of nanomaterials as fluorophores, fluorescence quenchers as reducing agents and as dendrimers for signal improvement and amplification, together with the use of aptamers to replace antibodies are described. Future research opportunities to overcome the current limitations on the available diagnostic approaches are also discussed.

scholarly journals Evaluation of a Low-Cost Commercial Actigraph and Its Potential Use in Detecting Cultural Variations in Physical Activity and Sleep

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3774
Author(s):  
Pavlos Topalidis ◽  
Cristina Florea ◽  
Esther-Sevil Eigl ◽  
Anton Kurapov ◽  
Carlos Alberto Beltran Leon ◽  
...  
Keyword(s):  
Physical Activity ◽  
Low Income ◽  
Large Scale ◽  
Low Cost ◽  
Low Income Countries ◽  
Time Data ◽  
Cultural Variations ◽  
Step Counts ◽  
Scale Step ◽  
Potential Use

The purpose of the present study was to evaluate the performance of a low-cost commercial smartwatch, the Xiaomi Mi Band (MB), in extracting physical activity and sleep-related measures and show its potential use in addressing questions that require large-scale real-time data and/or intercultural data including low-income countries. We evaluated physical activity and sleep-related measures and discussed the potential application of such devices for large-scale step and sleep data acquisition. To that end, we conducted two separate studies. In Study 1, we evaluated the performance of MB by comparing it to the GT3X (ActiGraph, wGT3X-BT), a scientific actigraph used in research, as well as subjective sleep reports. In Study 2, we distributed the MB across four countries (Austria, Germany, Cuba, and Ukraine) and investigated physical activity and sleep among these countries. The results of Study 1 indicated that MB step counts correlated highly with the scientific GT3X device, but did display biases. In addition, the MB-derived wake-up and total-sleep-times showed high agreement with subjective reports, but partly deviated from GT3X predictions. Study 2 revealed similar MB step counts across countries, but significant later wake-up and bedtimes for Ukraine than the other countries. We hope that our studies will stimulate future large-scale sensor-based physical activity and sleep research studies, including various cultures.

scholarly journals Adaptation and validation for Colombia of the WHO safe childbirth checklist

2018 ◽  
Vol 49 (3) ◽  
pp. 201-212
Author(s):  
Ana Carolina Amaya Arias ◽  
Óscar Zuluaga ◽  
Douglas Idárraga ◽  
Javier Hernando Eslava Schmalbach
Keyword(s):  
Low Income ◽  
Health Workers ◽  
Low Cost ◽  
Neonatal Morbidity ◽  
Neonatal Care ◽  
World Health ◽  
Low Income Countries ◽  
Safe Childbirth Checklist ◽  
Health Organization ◽  
Safe Childbirth

Introduction: Most maternal deaths that occur in developing countries are considered unfair and can be avoided. In 2008, The World Health Organization (WHO) proposed a checklist for childbirth care, in order to assess whether a simple, low-cost intervention had an impact on maternal and neonatal mortality in low-income countries. Objective: To translate, adapt and validate the content of the WHO Safe Childbirth Checklist (SCC) for its use in Colombia Methods: The checklist was translated and adapted to the Colombian context. It was subsequently validated by a panel of experts composed of 17 health workers with experience in maternal and neonatal care and safety. Reliability among judges was estimated (Rwg) and items were modified or added to each section of the list according to the results. Results: Modifications were made to 28 items, while 19 new items were added, and none was removed. The most important modifications were made to the management guidelines included in each item, and the items added refer to risks inherent to our environment. Conclusion: The Colombian version of the SCC will be a useful tool to improve maternal and neonatal care and thereby contribute to reducing maternal and neonatal morbidity and mortality in our country.

scholarly journals Fe0/H2O Filtration Systems for Decentralized Safe Drinking Water: Where to from Here?

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 429 ◽  
Author(s):  
Charles Nanseu-Njiki ◽  
Willis Gwenzi ◽  
Martin Pengou ◽  
Mohammad Rahman ◽  
Chicgoua Noubactep
Keyword(s):  
Drinking Water ◽  
Low Income ◽  
Universal Access ◽  
Low Cost ◽  
Low Income Countries ◽  
Future Research ◽  
Systematic Research ◽  
Safe Drinking Water ◽  
Iron Corrosion ◽  
Small Communities

Inadequate access to safe drinking water is one of the most pervasive problems currently afflicting the developing world. Scientists and engineers are called to present affordable but efficient solutions, particularly applicable to small communities. Filtration systems based on metallic iron (Fe0) are discussed in the literature as one such viable solution, whether as a stand-alone system or as a complement to slow sand filters (SSFs). Fe0 filters can also be improved by incorporating biochar to form Fe0-biochar filtration systems with potentially higher contaminant removal efficiencies than those based on Fe0 or biochar alone. These three low-cost and chemical-free systems (Fe0, biochar, SSFs) have the potential to provide universal access to safe drinking water. However, a well-structured systematic research is needed to design robust and efficient water treatment systems based on these affordable filter materials. This communication highlights the technology being developed to use Fe0-based systems for decentralized safe drinking water provision. Future research directions for the design of the next generation Fe0-based systems are highlighted. It is shown that Fe0 enhances the efficiency of SSFs, while biochar has the potential to alleviate the loss of porosity and uncertainties arising from the non-linear kinetics of iron corrosion. Fe0-based systems are an affordable and applicable technology for small communities in low-income countries, which could contribute to attaining self-reliance in clean water supply and universal public health.

Development of improved low-cost ceramic water filters for viral removal in the Haitian context

2014 ◽  
Vol 5 (1) ◽  
pp. 28-38 ◽  
Author(s):  
L. Guerrero-Latorre ◽  
M. Rusiñol ◽  
A. Hundesa ◽  
M. Garcia-Valles ◽  
S. Martinez ◽  
...  
Keyword(s):  
Low Income ◽  
Low Cost ◽  
World Health ◽  
Low Income Countries ◽  
Virus Removal ◽  
Ceramic Water Filters ◽  
Removal Efficiencies ◽  
Reductive Atmosphere ◽  
Health Organization ◽  
Water Filters

Household-based water treatment (HWT) is increasingly being promoted to improve water quality and, therefore, health status in low-income countries. Ceramic water filters (CWFs) are used in many regions as sustainable HWT and have been proven to meet World Health Organization (WHO) microbiological performance targets for bacterial removal (2–4 log); however, the described viral removal efficiencies are insufficient to significantly reduce the associated risk of viral infection. With the objective of improving the viral removal efficiencies of ceramic water filters, new prototypes with different oxide compositions and firing atmospheres have been developed and evaluated. For removal efficiencies human adenoviruses, MS2 bacteriophage and Escherichia coli were quantified in all prototypes. A new model of CWF that was fired in a reductive atmosphere presented virus and bacteria removal efficiencies greater than 3.0 log and 2.5 log, respectively, which would fulfill the viral targets that are recommended by the WHO. Ceramic characterization of the selected filters, which were fired in a reductive atmosphere, showed that a larger specific surface area than those of control filters and higher fraction of a positive Z-potential fraction are the most likely explanations for this increase in virus removal.

scholarly journals Radiological staging of rectal cancer in a resource limited setting

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Naradha Lokuhetty ◽  
Suranjith L. Seneviratne ◽  
Fathima Asma Rahman ◽  
Thanushka Marapana ◽  
Roshan Niloofa ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Low Income ◽  
Regional Lymph Node ◽  
Waiting Times ◽  
Low Income Countries ◽  
Lymph Node Staging ◽  
Sri Lankan ◽  
Resource Limited ◽  
Radiological Staging ◽  
The Status

Abstract Objective Current guidelines on rectal cancer (RC) management recommend pre-operative MRI for loco-regional staging and CT for staging of metastases. This allows appropriate selection of patients for chemo-radiotherapy (CRT). However, MRI is not freely available in many low-income countries. We assessed the status of pre-operative imaging for RC in Sri Lanka and evaluated the performance of CT in RC staging. Results A pre-tested interview-administered questionnaire was used to assess the pre-operative use of MRI and CT in RC. CT findings from 37 RC patients were then compared with histopathology findings. Of the 64 surgeons interviewed, 57 (89.1%) did not request an MRI for their RC patients. Reasons cited included limited availability and long waiting times due to competing health needs. A CT was requested by all. In RC, the overall accuracy of CT for T staging was 43.2% and 29.7% of T1–T2 tumours were over-staged as T3. The overall accuracy of CT for regional lymph node staging was 70.3%. In summary, CT alone is not suitable for RC staging in any setting. It leads to over-staging and patients may thus receive unnecessary CRT. Steps must be taken to improve access to pre-operative MRI among Sri Lankan RC patients.

scholarly journals COVID-19 control in low-income settings and displaced populations: what can realistically be done?

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Maysoon Dahab ◽  
Kevin van Zandvoort ◽  
Stefan Flasche ◽  
Abdihamid Warsame ◽  
Ruwan Ratnayake ◽  
...  
Keyword(s):  
Low Income ◽  
Treatment Options ◽  
Extended Period ◽  
Mitigation Strategies ◽  
Low Income Countries ◽  
Behavioural Science ◽  
Displaced Populations ◽  
Resource Limited ◽  
Wide Scale ◽  
Modelling Assumptions

Abstract COVID-19 prevention strategies in resource limited settings, modelled on the earlier response in high income countries, have thus far focused on draconian containment strategies, which impose movement restrictions on a wide scale. These restrictions are unlikely to prevent cases from surging well beyond existing hospitalisation capacity; not withstanding their likely severe social and economic costs in the long term. We suggest that in low-income countries, time limited movement restrictions should be considered primarily as an opportunity to develop sustainable and resource appropriate mitigation strategies. These mitigation strategies, if focused on reducing COVID-19 transmission through a triad of prevention activities, have the potential to mitigate bed demand and mortality by a considerable extent. This triade is based on a combination of high-uptake of community led shielding of high-risk individuals, self-isolation of mild to moderately symptomatic cases, and moderate physical distancing in the community. We outline a set of principles for communities to consider how to support the protection of the most vulnerable, by shielding them from infection within and outside their homes. We further suggest three potential shielding options, with their likely applicability to different settings, for communities to consider and that would enable them to provide access to transmission-shielded arrangements for the highest risk community members. Importantly, any shielding strategy would need to be predicated on sound, locally informed behavioural science and monitored for effectiveness and evaluating its potential under realistic modelling assumptions. Perhaps, most importantly, it is essential that these strategies not be perceived as oppressive measures and be community led in their design and implementation. This is in order that they can be sustained for an extended period of time, until COVID-19 can be controlled or vaccine and treatment options become available.

scholarly journals The reversible adjustable coupling: A lightweight and low-cost alignment component for the lower limb prosthesis

2017 ◽  
Vol 4 ◽  
pp. 205566831770642
Author(s):  
Kazuhiko Sasaki ◽  
Jutamat Pinitlertsakun ◽  
Pakwan Nualnim ◽  
Gary Guerra ◽  
Yuttapichai Sansook ◽  
...  
Keyword(s):  
Low Income ◽  
Lower Limb ◽  
External Rotation ◽  
Low Cost ◽  
Low Income Countries ◽  
Strength Tests ◽  
Lower Limb Prosthesis ◽  
Repetitive Loading ◽  
Limb Prosthesis ◽  
Anterior Posterior

Background The alignment of the lower limb prosthesis is an integral part of the prosthetic fitting. A properly aligned prosthesis contributes to optimal gait and overall function of the patient. The current offering of alignment componentry is expensive for low-income countries. The purpose of this study was to develop a lightweight and low-cost alignment coupler for the lower limb prosthesis. Methods An alignment coupler called the reversible adjustable coupling was designed and manufactured. Measurements of total anterior/posterior and medial/lateral and rotation in prostheses were recorded and mechanical testing performed. Swiftness and difficulty of use was also recorded. Results The reversible adjustable coupling permitted acceptable ranges of anterior/posterior and medial/lateral translation and 30° of internal and external rotation of prosthetic componentry. Repetitive loading of the coupling at a speed of 1 Hz under 1.28 kN load for 2000 cycles was successful, as were static and strength tests. Discussion The coupler provided acceptable ranges of anterior/posterior and medial/lateral and rotation adjustment and is acceptable for potential use in the alignment of both exoskeletal and endoskeletal prosthesis. The final weight of the component was 166 g and cost of $55.00 USD is affordable for low-income countries for use in clinical and educational settings.

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