The future of viral hepatitis testing: innovations in testing technologies and approaches.

A large burden of undiagnosed hepatitis virus cases remains globally. Despite the 257 million people living with chronic hepatitis B virus infection, and 71 million with chronic viraemic HCV infection, most people with hepatitis remain unaware of their infection. Advances in rapid detection technology have created new opportunities for enhancing access to testing and care, as well as monitoring of treatment. This article examines a range of other technological innovations that can be leveraged to provide more affordable and simplified approaches to testing for HBV and HCV infection and monitoring of treatment response. These include improved access to testing through alternative sampling methods (use of dried blood spots, oral fluids, self-testing) and combination rapid diagnostic tests for detection of HIV, HBV and HCV infection; more affordable options for confirmation of virological infection (HBV DNA and HCV RNA) such as point-of-care molecular assays, HCV core antigen and multi-disease polyvalent molecular platforms that make use of existing centralised laboratory based or decentralised TB and HIV instrumentation for viral hepatitis testing; and finally health system improvements such as integration of laboratory services for procurement and sample transportation and enhanced data connectivity to support quality assurance and supply chain management

Implementation of dual maternal HIV-Syphilis testing: The devil is in the details.

Correspondenc

Data connectivity: A critical tool for external quality assessment.

Point-of-care (POC) tests have been useful in increasing access to testing and treatment monitoring for HIV. Decentralising testing from laboratories to hundreds of sites around a country presents tremendous challenges in training and quality assurance. In order to address these concerns, companies are now either embedding connectivity in their new POC diagnostic instruments or providing some form of channel for electronic result exchange. These will allow automated key performance and operational metrics from devices in the field to a central database. Setting up connectivity between these POC devices and a central database at the Ministries of Health will allow automated data transmission, creating an opportunity for real-time information on diagnostic instrument performance as well as the competency of the operator through external quality assessment. A pilot programme in Zimbabwe shows that connectivity has significantly improve the turn-around time of external quality assessment result submissions and allow corrective actions to be provided in a timely manner. Furthermore, by linking the data to existing supply chain management software, stock-outs can be minimised. As countries are looking forward to achieving the 90-90-90 targets for HIV, such innovative technologies can automate disease surveillance, improve the quality of testing and strengthen the efficiency of health systems

Assuring the quality of diagnostic testing: The future is now.

No abstract available

Quality assurance for point-of-care testing in Zimbabwe

No abstract available

Indeterminate and discrepant rapid HIV test results in couples' HIV testing and counselling centres in Africa

<p>Abstract</p> <p>Background</p> <p>Many HIV voluntary testing and counselling centres in Africa use rapid antibody tests, in parallel or in sequence, to establish same-day HIV status. The interpretation of indeterminate or discrepant results between different rapid tests on one sample poses a challenge. We investigated the use of an algorithm using three serial rapid HIV tests in cohabiting couples to resolve unclear serostatuses.</p> <p>Methods</p> <p>Heterosexual couples visited the Rwanda Zambia HIV Research Group testing centres in Kigali, Rwanda, and Lusaka, Zambia, to assess HIV infection status. Individuals with unclear HIV rapid antibody test results (indeterminate) or discrepant results were asked to return for repeat testing to resolve HIV status. If either partner of a couple tested positive or indeterminate with the screening test, both partners were tested with a confirmatory test. Individuals with indeterminate or discrepant results were further tested with a tie-breaker and monthly retesting. HIV-RNA viral load was determined when HIV status was not resolved by follow-up rapid testing. Individuals were classified based on two of three initial tests as "Positive", "Negative" or "Other". Follow-up testing and/or HIV-RNA viral load testing determined them as "Infected", "Uninfected" or "Unresolved".</p> <p>Results</p> <p>Of 45,820 individuals tested as couples, 2.3% (4.1% of couples) had at least one discrepant or indeterminate rapid result. A total of 65% of those individuals had follow-up testing and of those individuals initially classified as "Negative" by three initial rapid tests, less than 1% were resolved as "Infected". In contrast, of those individuals with at least one discrepant or indeterminate result who were initially classified as "Positive", only 46% were resolved as "Infected", while the remainder was resolved as "Uninfected" (46%) or "Unresolved" (8%). A positive HIV serostatus of one of the partners was a strong predictor of infection in the other partner as 48% of individuals who resolved as "Infected" had an HIV-infected spouse.</p> <p>Conclusions</p> <p>In more than 45,000 individuals counselled and tested as couples, only 5% of individuals with indeterminate or discrepant rapid HIV test results were HIV infected. This represented only 0.1% of all individuals tested. Thus, algorithms using screening, confirmatory and tie-breaker rapid tests are reliable with two of three tests negative, but not when two of three tests are positive. False positive antibody tests may persist. HIV-positive partner serostatus should prompt repeat testing.</p

Diagnostic accuracy of tests to detect hepatitis B surface antigen: a systematic review of the literature and meta-analysis

Abstract Background Chronic Hepatitis B Virus (HBV) infection is characterised by the persistence of hepatitis B surface antigen (HBsAg). Expanding HBV diagnosis and treatment programmes into low resource settings will require high quality but inexpensive rapid diagnostic tests (RDTs) in addition to laboratory-based enzyme immunoassays (EIAs) to detect HBsAg. The purpose of this review is to assess the clinical accuracy of available diagnostic tests to detect HBsAg to inform recommendations on testing strategies in 2017 WHO hepatitis testing guidelines. Methods The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using 9 databases. Two reviewers independently extracted data according to a pre-specified plan and evaluated study quality. Meta-analysis was performed. HBsAg diagnostic accuracy of rapid diagnostic tests (RDTs) was compared to enzyme immunoassay (EIA) and nucleic-acid test (NAT) reference standards. Subanalyses were performed to determine accuracy among brands, HIV-status and specimen type. Results Of the 40 studies that met the inclusion criteria, 33 compared RDTs and/or EIAs against EIAs and 7 against NATs as reference standards. Thirty studies assessed diagnostic accuracy of 33 brands of RDTs in 23,716 individuals from 23 countries using EIA as the reference standard. The pooled sensitivity and specificity were 90.0% (95% CI: 89.1, 90.8) and 99.5% (95% CI: 99.4, 99.5) respectively, but accuracy varied widely among brands. Accuracy did not differ significantly whether serum, plasma, venous or capillary whole blood was used. Pooled sensitivity of RDTs in 5 studies of HIV-positive persons was lower at 72.3% (95% CI: 67.9, 76.4) compared to that in HIV-negative persons, but specificity remained high. Five studies evaluated 8 EIAs against a chemiluminescence immunoassay reference standard with a pooled sensitivity and specificity of 88.9% (95% CI: 87.0, 90.6) and 98.4% (95% CI: 97.8, 98.8), respectively. Accuracy of both RDTs and EIAs using a NAT reference were generally lower, especially amongst HIV-positive cohorts. Conclusions HBsAg RDTs have good sensitivity and excellent specificity compared to laboratory immunoassays as a reference standard. Sensitivity of HBsAg RDTs may be lower in HIV infected individuals

Evolution of HLA-B*5703 HIV-1 escape mutations in HLA-B*5703–positive individuals and their transmission recipients

HLA-B*57 is the class I allele most consistently associated with control of human immunodeficiency virus (HIV) replication, which may be linked to the specific HIV peptides that this allele presents to cytotoxic T lymphocytes (CTLs), and the resulting efficacy of these cellular immune responses. In two HIV C clade–infected populations in South Africa and Zambia, we sought to elucidate the role of HLA-B*5703 in HIV disease outcome. HLA-B*5703–restricted CTL responses select for escape mutations in three Gag p24 epitopes, in a predictable order. We show that the accumulation of these mutations sequentially reduces viral replicative capacity in vitro. Despite this, in vivo data demonstrate that there is ultimately an increase in viral load concomitant with evasion of all three HLA-B*5703–restricted CTL responses. In HLA-B*5703–mismatched recipients, the previously described early benefit of transmitted HLA-B*5703–associated escape mutations is abrogated by the increase in viral load coincident with reversion. Rapid disease progression is observed in HLA-matched recipients to whom mutated virus is transmitted. These data demonstrate that, although costly escape from CTL responses can progressively attenuate the virus, high viral loads develop in the absence of adequate, continued CTL responses. These data underline the need for a CTL vaccine against multiple conserved epitopes

Chromosome Missegregation in Alzheimer’s Disease Caused by Presenilin 1

Mutations in the presenilin 1 gene account for most early-onset familial Alzheimer\u27s disease (FAD). The presenilins and AD may also be related through a common involvement in the cell cycle. Here we report that one important aspect of the cell cycle---proper chromosome segregation---is dependent on presenilin function and therefore may be involved in AD pathogenesis. Specifically we find that FAD mutations in presenilin 1 (M146L and M146V) lead to chromosome missegregation and aneuploidy in vivo and in vitro: 1) Both metaphase chromosome analysis and in situ hybridization reveal significant aneuploidy in the lymphocytes and neurons of PS-1 transgenic mice. 2) Transiently transfected human cells expressing normal and, especially, mutant PS-1 develop aneuploidy within 48 hours, including trisomy 21, while cells transfected with dominant negative PS-1 genes lacking ?-secretase activity have no effect on chromosome segregation. 3) Analysis of mitotic spindles in the transfected cells reveals abnormal microtubule arrays and lagging chromosomes. The possible mechanisms by which cell cycle defects and chromosome missegregation induced by y-secretase may contribute to Alzheimer\u27s disease will be discussed

Re-imagining the future of diagnosis of Neglected Tropical Diseases

Neglected Tropical Diseases (NTDs) affect an estimated 1 billion people in 149 countries. The World Health Organization (WHO) prioritised 17 NTDs for control and elimination by 2020 and defined a Road Map to help countries reach these goals. Improved diagnostics for NTDs are essential for guiding treatment strategies at different thresholds of control, interruption of transmission, elimination and post-elimination surveillance. While substantial progress has been made in the last decade with chemotherapy, the same cannot be said of diagnostics, largely due to the perceived lack of a commercially viable market for NTD diagnostics.New sample in-answer out nucleic acid amplification technologies that can be performed at the point-of-care offer improved performance over current technologies and the potential to test for multiple pathogens using a single specimen. Finding commonalities for different NTDs in terms of geographic overlap, sentinel populations and treatment strategy will allow NTD programs to leverage these innovations to build cost-effective multiplex surveillance platforms. Connectivity solutions linking data from diagnostic laboratories and POC test readers/devices provide opportunities for automated surveillance systems to make health systems more efficient, improving patient outcomes and assessing impact of interventions in real time. New models of public–private product development partnerships are critical in leveraging diagnostic innovation in other priority area for better diagnosis, control and elimination of NTDs. Keywords: Neglected tropical diseases, Diagnostics, Control, Elimination, Surveillanc