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

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.

2021 ◽  
Vol 1 (1) ◽  
pp. 108-111
Author(s):  
Ronni Mol Joji ◽  
Mohammad Shahid

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.


2021 ◽  
Vol 9 ◽  
Author(s):  
Ada Melo-Vallès ◽  
Clara Ballesté-Delpierre ◽  
Jordi Vila

On March 12, the World Health Organization declared a pandemic following the exponential increase of SARS-CoV-2 cases. The rapid spread of the virus is due to both its high infectivity and the free circulation of unrecognized infectious cases. Thus, diagnostic testing is a key element to prevent further dissemination of the virus. Urged by WHO's call, laboratories worldwide have been working on nucleic acid tests protocols and immunoassays that became available, albeit poorly validated, within a comparatively short time. Since then, external studies evaluating these diagnostic tests have been published. The present study is a review of the COVID-19 diagnostic approaches, discussing both direct and indirect microbiological diagnoses. A compendium of the literature on commercial assays kits available to date is provided together with the conclusions drawn as well as RT-PCR protocols published by the WHO. Briefly, diagnostic accuracy varies according to time elapsed since symptom onset and evolves together with understanding of the COVID-19 disease. Taking into account all these variables will allow determining the most adequate diagnostic test to use and how to optimize diagnostic testing for COVID-19.


2020 ◽  
Vol 221 (Supplement_5) ◽  
pp. S519-S524
Author(s):  
William Godwin ◽  
Joaquin M Prada ◽  
Paul Emerson ◽  
P J Hooper ◽  
Ana Bakhtiari ◽  
...  

Abstract Background As the World Health Organization seeks to eliminate trachoma by 2020, countries are beginning to control the transmission of trachomatous inflammation–follicular (TF) and discontinue mass drug administration (MDA) with oral azithromycin. We evaluated the effect of MDA discontinuation on TF1–9 prevalence at the district level. Methods We extracted from the available data districts with an impact survey at the end of their program cycle that initiated discontinuation of MDA (TF1–9 prevalence <5%), followed by a surveillance survey conducted to determine whether TF1–9 prevalence remained below the 5% threshold, warranting discontinuation of MDA. Two independent analyses were performed, 1 regression based and 1 simulation based, that assessed the change in TF1–9 from the impact survey to the surveillance survey. Results Of the 220 districts included, TF1–9 prevalence increased to >5% from impact to surveillance survey in 9% of districts. Regression analysis indicated that impact survey TF1–9 prevalence was a significant predictor of surveillance survey TF1–9 prevalence. The proportion of simulations with >5% TF1–9 prevalence in the surveillance survey was 2%, assuming the survey was conducted 4 years after MDA. Conclusion An increase in TF1–9 prevalence may represent disease resurgence but could also be due to measurement error. Improved diagnostic tests are crucial to elimination of TF1–9 as a public health problem.


2020 ◽  
Vol 3 ◽  
pp. 8 ◽  
Author(s):  
Gerald Mboowa

On March 11, 2020 the World Health Organization (WHO) upgraded the status of the coronavirus disease 2019 (COVID-19) outbreak from epidemic to a global pandemic. This infection is caused by a novel coronavirus, SARS-CoV-2. Several rapid diagnostic tests have been developed at an astonishing pace; however, COVID-19 requires more highly specific rapid point-of-care diagnostic tests. This review describes the currently available testing approaches, as well as the available test assays including the Xpert® Xpress SARS-CoV-2 test (takes ~45 min) and Abbott ID COVID-19 test (5 min) as easy to use point-of-care tests for diagnosis of novel COVID-19 that have so far received the US Food and Drug Administration emergency use authorizations clearance. This review is correct as of the date published and will be updated as more diagnostic tests come to light.


2019 ◽  
Vol 9 (1) ◽  
pp. 111 ◽  
Author(s):  
Michelle A. Bulterys ◽  
Bradley Wagner ◽  
Maël Redard-Jacot ◽  
Anita Suresh ◽  
Nira R. Pollock ◽  
...  

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.


2018 ◽  
Author(s):  
Lucas Buyon ◽  
Randall Slaven ◽  
Paul M. Emerson ◽  
Jonathan King ◽  
Oscar Debrah ◽  
...  

AbstractTrachoma and Guinea Worm Disease (GWD) are neglected tropical diseases (NTDs) slated for elimination as a public health problem and eradication respectively by the World Health Organization. As these programs wind down, uncovering the last remaining cases becomes an urgent priority. In 2010, The Ghana Health Service, along with The Carter Center, Sightsavers, and other partners, conducted integrated case search for cases of both GWD and the last stage of trachoma disease, trachomatous trichiasis (TT), as well as providing treatment for trachoma to meet elimination and eradication targets. House to house case search for both diseases was conducted and two case management strategies were explored: a centralized referral to services method and a Point of Care (POC) delivery method. 835 suspected TT cases were discovered in the centralized method, of which 554 accepted surgery. 482 suspected TT cases were discovered in the POC method and all TT cases accepted surgery in the POC searches. The cost per TT case examined was lower in the POC searches compared to the centralized searches ($19.97 in the POC searches and $20.85 in the centralized searches). Both strategies resulted in high surgical uptake for TT surgery, with average uptakes of 72.4% and 83.9% for the centralized and POC searches respectively. We present here that house to house case search offering services at POC are feasible and a potential tool for elimination and eradication programs nearing their end.Author SummaryTrachoma and Guinea Worm Disease (GWD) are neglected tropical diseases (NTDs) slated for elimination as a public health problem and eradication respectively by the World Health Organization. As these programs wind down, uncovering the last remaining cases becomes an urgent priority in order to confirm that eradiation/elimination targets have been reached. Active case searches are one method of finding these last vestiges of disease. Searches for that look for multiple diseases are referred to as integrated searches. We piloted here integrated case searches for GWD and Trachoma with two case management strategies, a referral approach to a central location, and point of care approach (POC). POC approaches can difficult to implement in low resource settings because they require extensive personnel, financial, and logistical, support. However, POC approaches remove one of the biggest barriers to treatment, time spent traveling to a health center, and thus can improve treatment uptake. We found here that integrated active cases searches with a POC case management approach can be implemented in a low resource setting; and improve acceptance and uptake of trachoma examination and trichiasis surgery respectively without costing much more than the referral case management approach.


2020 ◽  
Author(s):  
Hossam Haick ◽  
Rotem Vishinkin ◽  
Rami Busool ◽  
Elias Mansour ◽  
Falk Fish ◽  
...  

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).


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ebru Saatçi

AbstractThe emergence of SARS-CoV-2, responsible for COVID-19 disease, has caused a substantial worldwide pandemic and has become a significant public health problem. World Health Organization (WHO) has declared COVID-19 as a devastating health emergency for all countries. Public health officials continue to monitor the situation closely to control this new virus-related outbreak. In order to continue to manage this pandemic, a fast and sensitive diagnosis of COVID-19 is attempted. Emerging tests have become an essential part of the management of the COVID-19 crisis. This review article aims to provide a detailed explanation of ongoing and new diagnostic technologies for SARS-CoV-2 and a summary of method principles. Examples of new diagnostic methods for providing efficient and rapid diagnostic tests for managing the SARS-CoV-2 outbreak are also mentioned.


Author(s):  
Michelle A. Bulterys ◽  
Bradley Wagner ◽  
Maël Redard-Jacot ◽  
Anita Suresh ◽  
Nira R. Pollock ◽  
...  

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.


Author(s):  
Madhura Jadhav ◽  
P. D. Londhe

Acute Diarrhoea is an important public health problem worldwide. The World Health Organization estimates that there are more than 1000 million cases of Acute Diarrhoea. Loose motion less than 2 weeks that labelled as Acute Diarrhoea. Diarrhoea is described in Ayurvedic classics with the name of ‘Atisara’. It means passing of excessive flow of watery stool through anus. Most important factor in the pathogenesis of Aamatisara is Mandagni. In present study 50 patients of Aamatisara were selected from OPD and IPD of Kayachikitsa department. For the clinical study Pathadi Ghanavati and Lajamanda was selected as the trial drug which was given for the duration of 7 days in the dose of 1gm twice a day. It was observed that 32% patients were from the age group 51-60 years, 70% were females, 62% were from lower-middle socio economic class. Sama Jivha was found in all the patients. Among results loose motion showed 98.75% relief, 97.82% showed improvement in Udarashoola, 97.43% improvement in Agnimandya and Daurbalya each, 100% relief was seen in Aruchi. All the symptoms showed highly significant results. Hence it can be concluded that Pathadi Ghanavati and Lajamanda is very effective remedy in the patients of Aamatisara.


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