Recency assays use one or more biomarkers to identify whether HIV infection in a person is recent (usually within a year or less) or longstanding. Recency assays have been used to estimate incidence in representative cross-sectional surveys and in epidemiological studies to better understand the pat...terns and distributions of new and longstanding HIV infections.
This technical guidance outlines best practices regarding the appropriate use of HIV recency assays for surveillance purposes and updates 2011 technical guidance from the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS) on the use of HIV recency assays.
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This Rapid Communication aims to inform national TB programmes and other stakeholders about the key implications of the latest evidence on the use of specific molecular assays as initial diagnostic tests of pulmonary and extrapulmonary TB and RR-TB, in adults and children.
Following review of evidence and advice from the Technical Advisory Group (TAG) on Tuberculosis (TB) Diagnostics and Laboratory Strengthening, the World Health Organization (WHO) announces that current WHO recommendations for the use of interferon-gamma release assays (IGRA) are also valid for Beij...ing Wantai’s TB-IGRA and Qiagen QuantiFERON-TB Gold Plus products. This expands the range of tests available to detect TB infection. Full details are provided in this WHO policy statement.
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UNAIDS/WHO 2015 | Reference
This publication aims to provide updated guidance on the specific use of yellow fever laboratory assays in the context of surveillance to be used across the Global Yellow Fever Laboratory Network for disease surveillance. In the recent years, new commercial assays became available and are now recomm...ended for use by WHO and this publication will support national program on the use of compound laboratory assays as per the most recent recommended testing algorithms. This piece is aligned with the elimination effort set in the comprehensive global strategy to eliminate yellow fever epidemics (EYE) strategy 2017-2026 and where its advisory laboratory technical working group actively contributed to its development. The target audiences are policy-makers and health workers.
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For the molecular diagnosis of Chagas disease by real-time PCR (polymerase chain reaction), optimization of diagnostic accuracy is desirable. The detection limit of real-time PCR assays for the diagnosis of Trypanosoma cruzi in human serum is affected by various influences including the choice of th...e nucleic acid extraction assay. In this study, three nucleic acid extraction assays were compared regarding their influence on the sensitivity of a T. cruzi-specific real-time PCR with 62 reference sera containing T. cruzi target DNA (deoxyribonucleotide acid). More than 95% of the positive sera were correctly identified after all three nucleic acid extraction strategies with a detection rate ranging from 96.8% (60/62) for the worst assay to 100% (62/62) for the best one. A matched pairs analysis for the comparison of the cycle threshold (Ct) values obtained with the 59 reference samples with positive real-time PCR results after all three nucleic acid extraction schemes indicated differences in a range of about 3 Ct steps. Summarized, all three compared nucleic acid extraction schemes were basically suitable for T. cruzi-specific PCR from serum with some minor differences. However, in the case of low quantities of circulating parasite DNA in the serum of a patient with Chagas disease, even minor effects can make a difference in the individual diagnosis.
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Current Issüs Arising from Tuberculosis Screening with Interferon-Gamma- Release Assays (IGRAs)
Pneumologie 2015; 69: 271–275
Interferon-γ Assays - Description and Assessment of a New Tool in the Diagnosis of Tuberculosis.
Haür B et al. Interferon-γ-Tests in der ...Pneumologie 2006; 60: 29-44
Many in-house and commercial assays that detect the COVID-19 virus have been developed or are currently under development. Many of these molecular assays are currently being validated in partner laboratories. An overview of assays that have applied to FIND for participation in their assay assessment... work can be found here
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WHO working group on HIV incidence assays meeting report
10–11 December 2015
Glion, Switzerland
UNAIDS/WHO working group on global HIV/AIDS and STI surveillance
WHO/HIV/2017.03
Annex to Selection and use of Ebola in vitro diagnostic assays
Zika and dengue viruses remain significant public health threats. These viruses share the same Aedes (Stegomyia) mosquito vectors and geographic distributions but infections cannot be readily distinguished clinically and need to be differentiated from each other, and from other circulating arboviral... and non-arboviral pathogens, using laboratory tests. This document provides guidance on current testing strategies for Zika and dengue virus infections with updates to the previous interim guidance for laboratory testing for ZIKV, addressing pregnant and non-pregnant patients respectively, and incorporates current guidance for dengue virus diagnostic testing. The choice of laboratory assays and interpretation of test results require careful consideration of epidemiology, patient history, and limitations of existing diagnostic tests.
This interim guidance is for use by staff of laboratories testing for Zika and dengue virus infections and for clinical practitioners and public health professionals providing clinical management or surveillance.
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Parasites & Vectors volume 11, Article number: 264 (2018)
Dengue creates a staggering epidemiological and economic burden for endemic countries. Without a specific therapy and with a commercial vaccine that presents some problems relative to its full effectiveness, initiatives to improve vector... control strategies, early disease diagnostics and the development of vaccines and antiviral drugs are priorities. In this study, we present the probable origins of dengue in America and the trajectories of its spread. Overall, dengue diagnostics are costly, making the monitoring of dengue epidemiology more difficult and affecting physicians’ therapeutic decisions regarding dengue patients, especially in developing countries. This review also highlights some recent and important findings regarding dengue in Brazil and the Americas. We also summarize the existing DENV polymerase chain reaction (PCR) diagnostic tests to provide an improved reference since these tests are useful and accurate at discriminating DENV from other flaviviruses that co-circulate in the Americas. Additionally, these DENV PCR assays ensure virus serotyping, enabling epidemiologic monitoring.
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Three classess of tests are now recommended in the latest consolidated guideles on tests for tuberculosis infection. It includes for the first-time a new class of Mycobacterium tuberculosis antigen-based skin tests (TBSTs), and the two existing classes of tests: the tuberculin skin test (TST) and t...he interferon-gamma release assays (IGRAs).
IGRAs and TBSTs use Mycobacterium tuberculosis complex specific antigens and represent a significant advancement to TST which has been used for over half a century.
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These guidelines provide updated evidence-based recommendations on the priority HCV-related topics from the 2018 WHO Guidelines for the care and treatment of persons diagnosed with chronic hepatitis C infection and the 2017 WHO Guidelines on hepatitis B and C testing. These priority areas are:
... direct-acting antiviral (DAA) treatment of adolescents and children ages ≥3 years of age
simplified HCV service delivery (decentralization, integration and task sharing)
HCV diagnostics – use of point-of-care (POC) HCV ribonucleic acid (RNA) assays and reflex HCV RNA testing.
These guidelines also update existing chapters without new recommendations, such as the inclusion of new manufacturers’ protocols on the use of dried blood spot (DBS) for HCV RNA testing and new data to inform the limit of detection for HCV RNA assays as a test of cure, in addition to their use for diagnosis.
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