scholarly journals Point-of-Care Urine LAM Tests for Tuberculosis Diagnosis: A Mini-Review

2019 ◽  
Author(s):  
Michelle A. Bulterys ◽  
Bradley Wagner ◽  
Maël Redard-Jacot ◽  
Anita Suresh ◽  
Nira R. Pollock ◽  
...  
Keyword(s):  
First Generation ◽  
Treatment Initiation ◽  
Point Of Care ◽  
Scale Up ◽  
World Health ◽  
Next Generation ◽  
Tuberculosis Diagnosis ◽  
Health Organization ◽  
Low Sensitivity ◽  
Control Implementation

Most diagnostic tests for tuberculosis (TB) rely on sputum samples, which are difficult to obtain and have low sensitivity in immunocompromised patients, patients with disseminated TB, and children, delaying treatment initiation. The World Health Organization (WHO) calls for the development of a rapid, biomarker-based, non-sputum test capable of detecting all forms of TB at the point-of-care to enable immediate treatment initiation. Lipoarabinomannan (LAM) is the only WHO-endorsed TB biomarker which can be detected in urine, an easily collected sample. This review discusses the characteristics of LAM as a biomarker, describes the performance of first-generation urine LAM tests and reasons for slow uptake, and presents considerations for developing the next-generation of more sensitive and impactful tests. Next-generation urine LAM tests have the potential to reach adult and pediatric patients regardless of HIV status or site of infection and facilitate global TB control. Implementation and scale-up of existing LAM tests and development of next-generation assays should be prioritized.

scholarly journals Point-Of-Care Urine LAM Tests for Tuberculosis Diagnosis: A Status Update

2019 ◽  
Vol 9 (1) ◽  
pp. 111 ◽  
Author(s):  
Michelle A. Bulterys ◽  
Bradley Wagner ◽  
Maël Redard-Jacot ◽  
Anita Suresh ◽  
Nira R. Pollock ◽  
...  
Keyword(s):  
First Generation ◽  
Treatment Initiation ◽  
Point Of Care ◽  
Scale Up ◽  
World Health ◽  
Next Generation ◽  
Tuberculosis Diagnosis ◽  
Health Organization ◽  
Low Sensitivity ◽  
Control Implementation

Most diagnostic tests for tuberculosis (TB) rely on sputum samples, which are difficult to obtain and have low sensitivity in immunocompromised patients, patients with disseminated TB, and children, delaying treatment initiation. The World Health Organization (WHO) calls for the development of a rapid, biomarker-based, non-sputum test capable of detecting all forms of TB at the point-of-care to enable immediate treatment initiation. Lipoarabinomannan (LAM) is the only WHO-endorsed TB biomarker that can be detected in urine, an easily collected sample. This status update discusses the characteristics of LAM as a biomarker, describes the performance of first-generation urine LAM tests and reasons for slow uptake, and presents considerations for developing the next generation of more sensitive and impactful tests. Next-generation urine LAM tests have the potential to reach adult and pediatric patients regardless of HIV status or site of infection and facilitate global TB control. Implementation and scale-up of existing LAM tests and development of next-generation assays should be prioritized.

scholarly journals Detecting tuberculosis: rapid tools but slow progress

2019 ◽  
Vol 9 (3) ◽  
pp. 80-83
Author(s):  
K. England ◽  
T. Masini ◽  
E. Fajardo
Keyword(s):  
Point Of Care ◽  
Scale Up ◽  
Critical Issue ◽  
World Health ◽  
High Turnover ◽  
Low Resource Settings ◽  
Laboratory Staff ◽  
Low Resource ◽  
Point Of Care Test ◽  
Health Organization

The World Health Organization (WHO) currently recommends Xpert® MTB/RIF as the initial test for all people with presumptive tuberculosis (TB). A number of challenges have been reported, however, in using this technology, particularly in low-resource settings. Here we examine these challenges, and provide our perspective of the barriers to Xpert scale-up as assessed through a survey in 16 TB burden countries in which the Médecins Sans Frontières is present. We observed that the key barriers to scale-up include a lack of policy adoption and implementation of WHO recommendations for the use of Xpert, resulting from high costs, poor sensitisation of clinical staff and a high turnover of trained laboratory staff; insufficient service and maintenance provision provided by the manufacturer; and inadequate resources for sustainability and expansion. Funding is a critical issue as countries begin to transition out of support from the Global Fund. While it is clear that there is still an urgent need for research into and development of a rapid, affordable point-of-care test for TB that is truly adapted for use in low-resource settings, countries in the meantime need to develop functional and sustainable Xpert networks in order to close the existing diagnostic gap.

scholarly journals Lipoarabinomannan as a Point-of-Care Assay for Diagnosis of Tuberculosis: How Far Are We to Use It?

2021 ◽  
Vol 12 ◽  
Author(s):  
Julio Flores ◽  
Juan Carlos Cancino ◽  
Leslie Chavez-Galan
Keyword(s):  
Diagnostic Tests ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
Public Health Problem ◽  
Etiologic Agent ◽  
Diagnostic Methods ◽  
World Health ◽  
Soluble Form ◽  
Health Organization ◽  
Low Sensitivity

Tuberculosis (TB) is still a severe public health problem; the current diagnostic tests have limitations that delay treatment onset. Lipoarabinomannan (LAM) is a glycolipid that is a component of the cell wall of the bacillus Mycobacterium tuberculosis, the etiologic agent of TB. This glycolipid is excreted as a soluble form in urine. The World Health Organization has established that the design of new TB diagnostic methods is one of the priorities within the EndTB Strategy. LAM has been suggested as a biomarker to develop diagnostic tests based on its identification in urine, and it is one of the most prominent candidates to develop point-of-care diagnostic test because urine samples can be easily collected. Moreover, LAM can regulate the immune response in the host and can be found in the serum of TB patients, where it probably affects a wide variety of host cell populations, consequently influencing the quality of both innate and adaptive immune responses during TB infection. Here, we revised the evidence that supports that LAM could be used as a tool for the development of new point-of-care tests for TB diagnosis, and we discussed the mechanisms that could contribute to the low sensitivity of diagnostic testing.

scholarly journals Profiles of Volatile Biomarkers Detect Tuberculosis from Skin

2020 ◽  
Author(s):  
Hossam Haick ◽  
Rotem Vishinkin ◽  
Rami Busool ◽  
Elias Mansour ◽  
Falk Fish ◽  
...  
Keyword(s):  
Point Of Care ◽  
World Health ◽  
Disease Spread ◽  
Clinical Samples ◽  
Resource Limited ◽  
Tb Diagnostics ◽  
Health Organization ◽  
Low Sensitivity ◽  
Test Requirements

Abstract Tuberculosis (TB) is an infectious disease that threatens >10 million people annually. Despite advances in TB diagnostics, millions of patients continue to receive insufficient diagnosis, as TB symptoms are not specific. Many existing bio-diagnostic tests are slow, have low sensitivity and/or specificity, and can be too expensive or complex for resource-limited settings. Early diagnosis of TB contributes to morbidity mitigation and prevents the disease spread. Here, we report on a new physiological pathway for TB diagnostics via TB-specific profile of volatile organic compounds (VOCs) that are detected and quantified from air trapped above the skin (“skin headspace”). Beyond the exploration aspect that relies on clinical samples from 636 individuals in two clinical sites, we demonstrate the utility of these VOC profiles in a point-of-care diagnosis, by means of specifically-designed intelligent nanoarray, both in lab setting and online, in-situ wearable devices. The results show excellent discrimination between active pulmonary TB patients and controls with 89.4% accuracy. This fulfills the triage TB test requirements according to the World Health Organization (WHO).

scholarly journals A 3D-printed magnetic digital microfluidic diagnostic platform for rapid colorimetric sensing of carbapenemase-producing Enterobacteriaceae

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Pojchanun Kanitthamniyom ◽  
Pei Yun Hon ◽  
Aiwu Zhou ◽  
Mohammad Yazid Abdad ◽  
Zhi Yun Leow ◽  
...  
Keyword(s):  
Point Of Care ◽  
Resistance Mechanism ◽  
Turnaround Time ◽  
World Health ◽  
Colorimetric Sensing ◽  
Resource Limited ◽  
Reaction Chambers ◽  
Technological Platform ◽  
Health Organization ◽  
Digital Microfluidic

AbstractCarbapenemase-producing Enterobacteriaceae (CPE) are a group of drug-resistant Gram-negative pathogens that are classified as a critical threat by the World Health Organization (WHO). Conventional methods of detecting antibiotic-resistant pathogens do not assess the resistance mechanism and are often time-consuming and laborious. We have developed a magnetic digital microfluidic (MDM) platform, known as MDM Carba, for the identification of CPE by measuring their ability to hydrolyze carbapenem antibiotics. MDM Carba offers the ability to rapidly test CPE and reduce the amount of reagents used compared with conventional phenotypic testing. On the MDM Carba platform, tests are performed in droplets that function as reaction chambers, and fluidic operations are accomplished by manipulating these droplets with magnetic force. The simple droplet-based magnetic fluidic operation allows easy system automation and simplified hands-on operation. Because of the unique “power-free” operation of MDM technology, the MDM Carba platform can also be operated manually, showing great potential for point-of-care testing in resource-limited settings. We tested 27 bacterial isolates on the MDM Carba platform, and the results showed sensitivity and specificity that were comparable to those of the widely used Carba NP test. MDM Carba may shorten the overall turnaround time for CPE identification, thereby enabling more timely clinical decisions for better clinical outcomes. MDM Carba is a technological platform that can be further developed to improve diagnostics for other types of antibiotic resistance with minor modifications.

scholarly journals Tuberculosis diagnosis and treatment under uncertainty

2019 ◽  
Vol 116 (46) ◽  
pp. 22990-22997
Author(s):  
Rachel Cassidy ◽  
Charles F. Manski
Keyword(s):  
Diagnostic Test ◽  
Diagnostic Testing ◽  
World Health ◽  
Smear Microscopy ◽  
Theoretic Model ◽  
Test Accuracy ◽  
Partial Knowledge ◽  
Deep Uncertainty ◽  
Tuberculosis Diagnosis ◽  
Health Organization

In 2017, 1.6 million people worldwide died from tuberculosis (TB). A new TB diagnostic test—Xpert MTB/RIF from Cepheid—was endorsed by the World Health Organization in 2010. Trials demonstrated that Xpert is faster and has greater sensitivity and specificity than smear microscopy—the most common sputum-based diagnostic test. However, subsequent trials found no impact of introducing Xpert on morbidity and mortality. We present a decision-theoretic model of how a clinician might decide whether to order Xpert or other tests for TB, and whether to treat a patient, with or without test results. Our first result characterizes the conditions under which it is optimal to perform empirical treatment; that is, treatment without diagnostic testing. We then examine the implications for decision making of partial knowledge of TB prevalence or test accuracy. This partial knowledge generates ambiguity, also known as deep uncertainty, about the best testing and treatment policy. In the presence of such ambiguity, we show the usefulness of diversification of testing and treatment.

PREDICTORS OF MALE CIRCUMCISION AMONG MEN AGED 15–35 YEARS IN HARARE, ZIMBABWE

2017 ◽  
Vol 50 (2) ◽  
pp. 193-211
Author(s):  
Kudzaishe Mangombe ◽  
Ishumael Kalule-Sabiti
Keyword(s):  
Hiv Prevention ◽  
Male Circumcision ◽  
Employment Status ◽  
Scale Up ◽  
World Health ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Medical Male Circumcision ◽  
Sub Saharan ◽  
Health Organization

SummaryMedical male circumcision has been recommended by the World Health Organization as part of a comprehensive approach to HIV prevention. Zimbabwe is one of the fourteen sub-Saharan countries that embarked on the Medical Male Circumcision (MMC) programme. However, the country has not yet met male circumcision targets. This paper examines the predictors of male circumcision in Zimbabwe. A cross-sectional survey was conducted on 784 men aged 15–35 years in Harare, Zimbabwe. Negative log-log logistic regression analysis was used to determine the predictors of male circumcision. The main predictors of circumcision were age, employment status, ever tested for HIV, approval of HIV testing prior to circumcision, knowledge about male circumcision and attitudes towards male circumcision. By and large, participants had good knowledge about male circumcision and viewed HIV prevention with a reasonably positive attitude. The identification of these predictors can be used to scale up the demand for male circumcision in Zimbabwe.

scholarly journals The Association of Retinopathy and Plasma Glucose and HbA1c: A Validation of Diabetes Diagnostic Criteria in a Chinese Population

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Rui Zhang ◽  
Yufeng Li ◽  
Simin Zhang ◽  
Xiaoling Cai ◽  
Xianghai Zhou ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Plasma Glucose ◽  
Chinese Population ◽  
High Specificity ◽  
Population Based ◽  
World Health ◽  
Who Criteria ◽  
Receiver Operating Characteristic Curves ◽  
Health Organization ◽  
Low Sensitivity

Aims. This study aimed to evaluate the associations of diabetic retinopathy (DR) with fasting plasma glucose (FPG), 2-hour postload plasma glucose (2hPG), and glycated hemoglobin A1c (HbA1c) in a Chinese population.Materials and Methods. A total of 3124 participants, identified from a population-based survey in Pinggu district, were examined by retinal photography (45°). DR was classified according to the Early Treatment Diabetic Retinopathy Study scale. FPG, 2hPG, and HbA1c were tested and categorized by deciles, with the prevalence of DR calculated in each decile.Results. The prevalence of DR increased sharply in the 10th deciles, when FPG exceeded 7.03 mmol/L and HbA1c exceeded 6.4%. Analysis of the receiver operating characteristic curves showed that the optimal cutoffs for detecting DR were 6.52 mmol/L and 5.9% for FPG and HbA1c, respectively. The World Health Organization (WHO) criteria for diagnosing diabetes showed high specificity (90.5–99.5%) and low sensitivity (35.3–65.0%). Further, 6 individuals with retinopathy had normal plasma glucose; however, their characteristics did not differ from those without retinopathy.Conclusions. Thresholds of FPG and HbA1c for detecting DR were observed, and the WHO criteria of diagnosing diabetes were shown to have high specificity and low sensitivity in this population.

scholarly journals The Role of Antigen Rapid Diagnostic Test in COVID-19 Diagnosis

2021 ◽  
Vol 1 (1) ◽  
pp. 108-111
Author(s):  
Ronni Mol Joji ◽  
Mohammad Shahid
Keyword(s):  
Diagnostic Tests ◽  
Point Of Care ◽  
Rapid Diagnostic Tests ◽  
World Health ◽  
Complementary Role ◽  
Reverse Transcription Quantitative Pcr ◽  
Highly Sensitive ◽  
Health Organization ◽  
Random Screening

Since the emergence of a novel infection due to the SARS-CoV-2 virus (COVID-19), the World Health Organization has urged countries to develop diagnostic tests to combat the pandemic. Molecular assays were developed following the release of the gene sequence of the virus in January 2020. Reverse transcription-quantitative PCR (RT-qPCR) is taken as the gold standard for the diagnosis of COVID-19. However, due to its limitations, highly sensitive methods for detecting antigens (antigen rapid diagnostic tests) have been developed that would help in a timely and accurate diagnosis. Antigen rapid diagnostic tests (Ag-RDTs) can help guide patient management at the point of care by random screening, re-testing, and timely decision-making in the field of public health. When the affordability and validity of the diagnostic assay are involved, no assay can show 100% correct results. Further studies need to be done to better understand the response of the Ag-RDTs in different settings. Nevertheless, Ag-RDTs can play a complementary role in the response and case management of COVID-19.

scholarly journals Lung ultrasound patterns in pediatric pneumonia in Mozambique and Pakistan

2020 ◽  
pp. 00518-2020
Author(s):  
Amy Sarah Ginsburg ◽  
Pio Vitorino ◽  
Zunera Qasim ◽  
Jennifer L. Lenahan ◽  
Jun Hwang ◽  
...  
Keyword(s):  
Interrater Reliability ◽  
Lung Ultrasound ◽  
Point Of Care ◽  
Integrated Management ◽  
Secondary Analysis ◽  
World Health ◽  
P Value ◽  
Pediatric Pneumonia ◽  
District Hospitals ◽  
Health Organization

ObjectiveImproved pneumonia diagnostics are needed, particularly in resource-constrained settings. Lung ultrasound (LUS) is a promising point-of-care imaging technology for diagnosing pneumonia. The objective was to explore LUS patterns associated with pediatric pneumonia.MethodsWe conducted a prospective, observational study among children aged 2 through 23 months with World Health Organization Integrated Management of Childhood Illness chest-indrawing pneumonia and among children without fast breathing, chest indrawing or fever (no pneumonia cohort) at two district hospitals in Mozambique and Pakistan. We assessed LUS and chest radiograph (CXR) examinations, and viral and bacterial nasopharyngeal carriage, and performed a secondary analysis of LUS patterns.ResultsLUS demonstrated a range of distinctive patterns that differed between children with and without pneumonia and between children in Mozambique versus Pakistan. The presence of LUS consolidation or interstitial patterns was more common in children with chest-indrawing pneumonia than in those without pneumonia. Consolidations were also more common among those with only bacterial but no viral carriage detected (50.0%) than among those with both (13.0%) and those with only virus detected (8.3%;p-value 0.03). LUS showed high interrater reliability among expert LUS interpreters for overall determination of pneumonia (κ=0.915), consolidation (κ=0.915), and interstitial patterns (κ=0.901), but interrater reliability between LUS and CXR for detecting consolidations was poor (κ=0.159, Pakistan) to fair (κ=0.453, Mozambique).DiscussionPattern recognition was discordant between LUS and CXR imaging modalities. Further research is needed to define and standardise LUS patterns associated with pediatric pneumonia and to evaluate the potential value of LUS as a reference standard.

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