In-field evaluation of Xpert® HCV viral load Fingerstick assay in people who inject drugs in Tanzania

Point-of-Care Testing for Hepatitis C in the Priority Settings of Mental Health, Prisons, and Drug and Alcohol Facilities-the PROMPt Study

BACKGROUND

A barrier to hepatitis C virus (HCV) cure is conventional testing. The aim of this study was to evaluate the effect of HCV antibody and RNA point-of-care testing (POCT) on testing rates, linkage to care, treatment, and acceptability of testing in 3 priority settings in Australia.

METHODS

Participants were enrolled in an interventional cohort study at a reception prison, inpatient mental health service, and inpatient alcohol and other drug unit, between October 2020 and December 2021. HCV POCT was performed using SD Bioline HCV antibody fingerstick test and a reflexive Xpert HCV Viral Load Fingerstick test using capillary blood samples. A retrospective audit of HCV testing and treatment data was performed at each site for the preceding 12-month period to generate a historical control.

RESULTS

A total of 1549 participants received a HCV antibody test with 17% (264 of 1549) receiving a positive result, of whom 21% (55 of 264) tested HCV RNA positive. Across all settings the rate of testing per year significantly increased between the historical controls and the study intervention period by 2.57 fold (rate ratio, 2.57 [95% confidence interval, 2.32-2.85]) for HCV antibody testing and 1.62 (rate ratio, 1.62 [95% confidence interval, 1.31-2.01]) for RNA testing. Treatment uptake was higher during the POCT intervention (86% [47 of 55]; P = .01) compared to the historical controls (61% [27 of 44]).

CONCLUSIONS

This study demonstrated across 3 settings that the use of HCV antibody and RNA POCT increased testing rates, treatment uptake, and linkage to care. The testing model was highly acceptable for most participants.

CLINICAL TRIALS REGISTRATION

ACTRN-12621001578897.

Molecular Point-of-Care Testing for Hepatitis C: Available Technologies, Pipeline, and Promising Future Directions

Hepatitis C virus (HCV) remains a major public health problem, despite the availability of effective treatments. In many areas, the ability to diagnose HCV infection at the point of care is key to scaling up access to care and treatment. To achieve this, an accurate, easy-to-use, and affordable diagnostic tool is required-this would enable decentralized testing and the creation of one-stop centers to eliminate gaps in the care cascade, which would help reach the millions of people with undiagnosed HCV infection in low- and middle-income countries and high-risk populations in high-income countries. In this review, we examine the current state of point-of-care molecular technologies, the advantages and limitations of currently available devices (both near- and true-point-of-care), the potential of molecular testing to transform diagnostic medicine in the future, and the challenges that need to be addressed for broader adoption of this technology in routine clinical practice.

What Hepatitis C Virus (HCV) Diagnostic Tools Are Needed to Advance Diagnosis of Current HCV Infection in Outreach Settings and in a Nonclinical Setting?

Given the growing hepatitis C virus (HCV) epidemic in the United States, it is imperative to implement a coordinated, equitable public health approach to HCV testing that will facilitate immediate access to treatment, especially for individuals with limited healthcare access and those who inject drugs. Point-of-care RNA diagnostic tests have the greatest potential to address this need. Future regulatory approval has been facilitated by a recent change in the US Food and Drug Administration's approach to evaluating point-of-care diagnostic tests that have been developed and validated.

Point-of-Care Testing for Hepatitis Viruses: A Growing Need

Viral hepatitis, caused by hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), or hepatitis E virus (HEV), is a major global public health problem. These viruses cause millions of infections each year, and chronic infections with HBV, HCV, or HDV can lead to severe liver complications; however, they are underdiagnosed. Achieving the World Health Organization's viral hepatitis elimination goals by 2030 will require access to simpler, faster, and less expensive diagnostics. The development and implementation of point-of-care (POC) testing methods that can be performed outside of a laboratory for the diagnosis of viral hepatitis infections is a promising approach to facilitate and expedite WHO's elimination targets. While a few markers of viral hepatitis are already available in POC formats, tests for additional markers or using novel technologies need to be developed and validated for clinical use. Potential methods and uses for the POC testing of antibodies, antigens, and nucleic acids that relate to the diagnosis, monitoring, or surveillance of viral hepatitis infections are discussed here. Unmet needs and areas where additional research is needed are also described.

CHIME - A tailored HCV microelimination project in Viennese people who inject drugs at drug centralized substitution centers

Background

Hepatitis C remains highly prevalent among people who inject drugs (PWIDs). We propose an integrated approach for screening/diagnostic testing and treatment in 6,665 Viennese PWIDs registered to access opioid agonist therapy (OAT).

Methods

OAT prescriptions were required monthly at one of nine approved authorities, making them ideal platforms for hepatitis C virus (HCV) screening. All PWIDs attending these authorities between January 2019 and March 2020 were offered on-site HCV screening, and consecutive HCV RNA PCR in case of positive HCV serology. In HCV viremic PWIDs, offsite referral to HCV care and treatment according to directly observed therapy (DOT) alongside OAT were performed.

Results

4,327/6,665 (64.9%) individuals were contacted before the COVID-19-related project discontinuation. There were 1,538/4,327 (35.5%) individuals who had participated in the study. HCV serology was available in 1,510/1,538 (98.2%): 795/1,519 (52.6%) had a positive serology, among whom 632 (79.5%) were followed-up with a PCR test. In 8/1,538 (0.5%) additional study participants HCV RNA PCR was assessed without prior serological screening. 239/640 (37.3%) individuals were HCV viremic with 51 (21.3%) having started on direct-acting antivirals (DAAs). 48/51 (94.1%) had completed treatment, among whom 42 (87.5% according to ITT) had achieved sustained virologic response at 12 weeks after completing treatment (SVR12) and 6 (12.5%) had been lost to follow-up after completion of therapy (SVR12 according to mITT: 42/42, 100%). No treatment failures had occurred.

Conclusion

Providing integrated point-of-care HCV screening/diagnostic testing at central OAT approved centers, followed by DOT with DAAs, represents an effective HCV microelimination strategy. While some PWIDs were lost in the cascade to cure and the absolute number of SVR was limited by the COVID-19 pandemic, our approach will allow linkage to care in a large proportion of Viennese PWIDs.

Evaluation of Simplified HCV Diagnostics in HIV/HCV Co-Infected Patients in Myanmar

To evaluate a decentralised testing model and simplified treatment protocol of hepatitis C virus (HCV) infection to facilitate treatment scale-up in Myanmar, this prospective, observational study recruited HIV-HCV co-infected outpatients receiving sofosbuvir/daclatasvir in Yangon, Myanmar. The study examined the outcomes and factors associated with a sustained virological response (SVR). A decentralised "hub-and-spoke" testing model was evaluated where fingerstick capillary specimens were transported by taxi and processed centrally. The performance of the Xpert HCV VL Fingerstick Assay in detecting HCV RNA was compared to the local standard of care ( plasma HCV RNA collected by venepuncture). Between January 2019 and February 2020, 162 HCV RNA-positive individuals were identified; 154/162 (95%) initiated treatment, and 128/154 (84%) returned for their SVR12 visit. A SVR was achieved in 119/154 (77%) participants in the intent-to-treat population and 119/128 (93%) participants in the modified-intent-to-treat population. Individuals receiving an antiretroviral therapy were more likely to achieve a SVR (with an odds ratio (OR) of 7.16, 95% CI 1.03-49.50), while those with cirrhosis were less likely (OR: 0.26, 95% CI 0.07-0.88). The sensitivity of the Xpert HCV VL Fingerstick Assay was 99.4% (95% CI 96.7-100.0), and the specificity was 99.2% (95% CI 95.9-99.9). A simplified treatment protocol using a hub-and-spoke testing model of fingerstick capillary specimens can achieve an SVR rate in LMIC comparable to well-resourced high-income settings.

Quality Assurance for Hepatitis C Virus Point-of-Care Diagnostics in Sub-Saharan Africa

As part of a multinational study to evaluate the Bioline Hepatitis C virus (HCV) point-of-care (POC) testing in sub-Saharan Africa (SSA), this narrative review summarises regulatory standards and quality indicators for validating and approving HCV clinical diagnostics. In addition, this review also provides a summary of their diagnostic evaluations using the REASSURED criteria as the benchmark and its implications on the WHO HCV elimination goals 2030.

Challenges and best practices for hepatitis C care among people who inject drugs in resource limited settings: focus group discussions with healthcare providers in Kenya

People who inject drugs (PWID) living with Hepatitis C (HCV) in low- and middle-income countries face substantial barriers to HCV care. We sought to gain healthcare providers' perspectives on challenges and best practices for HCV care provision among PWID in Kenya. We conducted three focus group discussions (FGD) with 23 healthcare providers working with PWID living with HCV in Nairobi and Mombasa. Transcribed interviews were analysed thematically. Overarching themes regarding HCV prevention and treatment were: (1) lack of HCV-related knowledge at the provider and patient levels; (2) stigmatisation of people living with HCV and PWID; and (3) difficulties among PWID with navigating the healthcare system. Some providers suggested systematically integrating HCV care into existing PWID-specific harm reduction programs to improve HCV care provision as well as creating national HCV guidelines to guide clinicians. This study highlights the need for national HCV treatment guidelines and increased public HCV education, as well as culturally sensitive models integrating HCV care into programs PWID are already accessing. These strategies will be useful in improving access to HCV care among PWID and has the potential to decrease HCV transmission and prevalence among this vulnerable population.

Diagnostic Accuracy of Point-of-Care HCV Viral Load Assays for HCV Diagnosis: A Systematic Review and Meta-Analysis

Despite the widespread availability of curative treatment with direct-acting antivirals, a significant proportion of people with HCV remain undiagnosed and untreated. New point-of-care (PoC) HCV RNA assays that can be used in clinical settings may help expand access to testing and treatment. This study aimed to evaluate the diagnostic performance of PoC HCV viral load assays compared to laboratory-based testing. Methods: We searched three databases for studies published before May 2021 that evaluated PoC HCV RNA assays against a laboratory NAT reference standard (Prospero CRD42021269022). Random effects bivariate models were used to summarize the estimates. Stratified analyses were performed based on geographic region, population (PWID, etc.), and specimen type (serum/plasma or fingerstick; fresh or frozen). We used the GRADE approach to assess the certainty of the evidence. Results: A total of 25 studies were eligible. We evaluated five different commercially available viral load assays. The pooled sensitivity and specificity were 99% (95% CI: 98−99%) and 99% (95% CI: 99−100%), respectively. High sensitivity and specificity were observed across different assays, study settings (including LMICs and HICs), and populations. There was a small but statistically significant reduction in sensitivity for fingersticks compared to serum or plasma samples (98% vs. 100%, p < 0.05), but the specificity was similar between frozen and fresh samples. The evidence was rated as moderate-high certainty. Conclusions: PoC HCV viral load assays demonstrate excellent diagnostic performance in various settings and populations. The WHO now recommends using PoC HCV viral load assays as an additional strategy to promote access to confirmatory viral load testing and treatment.

Feasibility of decentralised, task-shifted hepatitis C testing and treatment services in urban Myanmar: implications for scale-up

OBJECTIVES

To assess the feasibility considerations for a decentralised, one-stop-shop model of care implemented in Yangon, Myanmar.

SETTING

Two primary care level clinics in urban Yangon, Myanmar.

DESIGN

This is a feasibility study of a highly effective care model. Using Intervention Complexity Framework by Gericke et al, we collated and analysed programmatic data and evaluation data to outline key project implementation requirements and experiences.

PARTICIPANTS

Programmatic data were collected from clinical records, GeneXpert device test and maintenance reports, national guidelines, product and device instructions and site monitoring visit reports. Healthcare providers involved in delivering care model contributed interview data.

RESULTS

The main feasibility considerations are appropriate storage for test kits and treatments (in response to temperature and humidity requirements), installation of a continuous stable electricity supply for the GeneXpert device, air-conditioning for the laboratory room hosting GeneXpert, access to a laboratory for pretreatment assessments and clear referral pathways for specialist consultation when required. Lessons from our project implementation experiences included the extensive time requirements for patient education, the importance of regular error monitoring and stock storage reviews and that flexible appointment scheduling and robust reminder system likely contributed to high retention in care.

CONCLUSIONS

Detailed documentation and dissemination of feasibility requirements and implementation considerations is vital to assist others to successfully implement a similar model of care elsewhere. We provide 10 recommendations for successful implementation.

TRIAL REGISTRATION NUMBER

The trial was registered at ClinicalTrials.gov NCT03939013 on May 6, 2019. This manuscript presents post-results data on feasibility.

Time to complete hepatitis C cascade of care among patients identified during mass screening campaigns in rural Rwanda: a retrospective cohort study

Background

Since the discovery of direct-acting antivirals, treatment for hepatitis C virus (HCV) is increasingly accessible in low-resource settings, but quality of care in these settings is not known. We described progression through the cascade of care among individuals who screened positive for HCV antibodies during a mass screening campaign in Kirehe and Kayonza, two rural Rwandan districts, in September 2019.

Methods

This retrospective cohort study used routine clinical data to assess proportions of participants completing each stage of the cascade of care, including: (a) screening positive on rapid diagnostic test; (b) return of initial viral load results; (c) detectable viral load; (d) treatment assessment; (e) treatment initiation; (f) return of sustained virological response (SVR12) results; and (g) achieving SVR12. We proposed three indicators to assess timely care provision and used medians and interquartile ranges (IQR) to describe the time to complete the cascade of care.

Results

Overall, 666 participants screened HCV positive, among them, 452 (68.1%) were female and median age was 61 years (IQR: 47, 70). Viral load results were returned for 537 (80.6%) participants of whom 448 (83.4%) had detectable viral loads. Of these, 398 (88.8%) were assessed for treatment, 394 (99%) were initiated, but only 222 (56.3%) had results returned for SVR12. Among those with SVR12 results, 208 (93.7%) achieved SVR12. When assessing timely care provision, we found 65.9% (95% CI: 62.0, 69.7) of initial viral load results were returned ≤ 30 days of screening; 45% (95% CI: 40.1, 49.8) of people with detectable viral load completed treatment assessment ≤ 90 days of initial viral load results; and 12.5% (95% CI: 9.2, 16.3) of SVR12 results were returned ≤ 210 days of treatment initiation among those who initiated treatment. The overall median time from screening to SVR12 assessment was 437 days.

Conclusion

Despite high rates of SVR12 among those who completed all stages of the cascade of care, we identified gaps and delays in the treatment cascade. Improving communication between viral load testing hubs and health facilities could reduce the turn-around time for viral load testing, and actively monitor timeliness of care provision could improve quality of HCV care.

Diagnostic accuracy of assays using point-of-care testing or dried blood spot samples for the determination of HCV RNA: a systematic review

BACKGROUND

Fingerstick point-of-care and dried-blood-spot (DBS) HCV RNA testing increases testing uptake and linkage to care. This systematic review evaluated the diagnostic accuracy of point-of-care testing and DBS to detect HCV RNA.

METHODS

Bibliographic databases and conference presentations were searched for eligible studies. Meta-analysis was used to pool estimates.

RESULTS

Of 359 articles identified, 43 studies were eligible and included. When comparing the Xpert HCV Viral Load Fingerstick assay to venous blood samples (7 studies with 987 samples), the sensitivity and specificity for HCV RNA detection was 99% (95% CI:98%-100%) and 99% (95% CI:96%-100%) and for HCV RNA quantification was 100% (95% CI:93%-100%) and 100% (95% CI:94%-100%). The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing was 6% (95% CI:3%-11%). When comparing DBS to venous blood samples (28 studies with 3988 samples), the sensitivity and specificity for HCV RNA detection was 97% (95% CI:95%-98%) and 100% (95% CI:98%-100%) and for HCV RNA quantification was 98% (95% CI:96%-99%) and 100% (95% CI:95%-100%).

CONCLUSION

Excellent diagnostic accuracy was observed across assays for detection of HCV RNA from fingerstick and DBS samples. The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing highlights the importance of operator training and quality assurance programs.

Cost effectiveness of simplified HCV screening-and-treatment interventions for people who inject drugs in Dar-es-Salaam, Tanzania

BACKGROUND

Compared to other countries in sub-Saharan Africa, Tanzania has a relatively progressive illicit drug harm reduction (HR) policy, through a predominantly opioid substitution therapy-based programme. However, access to hepatitis C virus (HCV) diagnosis and curative direct acting antiviral therapy remains elusive. We developed a cost-effectiveness model to evaluate a simplified HCV screening-and-treatment intervention amongst PWID in Dar-es-Salaam, Tanzania.

METHODS

A decision tree and Markov state transition model compared existing practice (no access to HCV viral confirmation and treatment) with the integration of point-of-care HCV screening and treatment within (1) existing HR services and (2) expansion to include PWID not currently engaged in HR. Outcome measures were screening, treatment, HR and disease-related costs per PWID, quality-adjusted life years (QALY) and disability adjusted life years (DALY). Cost-effectiveness was evaluated from a healthcare payer's perspective over a 30-year time horizon over a range of willingness-to-pay thresholds (USD$273 to USD$1,050). Both deterministic and probabilistic sensitivity analyses have been conducted.

RESULTS

Assuming a chronic HCV prevalence of 18.8%, screening-and-treatment in existing HR settings resulted in an ICER per QALY-gained and DALY averted of USD$633 and USD$1,161, respectively. Expanding to include an outreach programme for unengaged PWID yielded an ICER per QALY-gained and DALY-averted of USD$4,091 and USD$10,288. Factors affecting the sensitivity of the ICER value included the cost of HR and the health utility of non-cirrhotic disease states.

CONCLUSION

Simplified HCV screening and treatment of PWID has the potential to be cost-effective in Dar-es-Salaam, Tanzania. In practice, synergism of human and financial resources with established health programmes may offer a pragmatic solution to minimise operational costs.

The Practicability of the Xpert HCV Viral Load Fingerstick Point-of-Care Assay in Primary Care Settings

Linkage to care presents one obstacle toward eliminating HCV, and the current two-step pathway (anti-HCV, followed by HCV-RNA testing) results in the loss of patients. HCV screening was tested in the primary care setting with the fingerstick Xpert HCV viral load point-of-care assay to analyze the practicability of immediate diagnosis. Anti-HCV (Cobas) and HCV-RNA (Cobas Amplicor version 2.0, only performed if anti-HCV was positive) were analyzed centrally as the gold standard. The Xpert assay was performed by 10 primary care private practices. In total, 622 patients were recruited. Five individuals (0.8%) were anti-HCV positive, and one was HCV-RNA positive. The Xpert test was valid in 546/622 (87.8%) patients. It was negative in 544 and positive in 2 cases, both of whom were anti-HCV negative. The HCV-RNA PCR and the Xpert test were both negative in 4/5 anti-HCV-positive cases, and the individual with HCV-RNA 4.5 × 106 IU/mL was not detected by the Xpert test. Primary care physicians rated the Xpert test practicability as bad, satisfactory, or good in 6%, 13%, and 81%, respectively, though 14/29 (48%) bad test ratings were assigned by a single practice. Despite adequate acceptance, interpretability and diagnostic performance in primary care settings should be further evaluated before its use in HCV screening can be recommended.

Rapid Diagnostics for Hepatitis B and C Viruses in Low- and Middle-Income Countries

The global health challenge posed by hepatitis B virus (HBV) and hepatitis C virus (HCV) persists, especially in low-and-middle-income countries (LMICs), where underdiagnosis of these viral infections remains a barrier to the elimination target of 2030. HBV and HCV infections are responsible for most liver-related mortality worldwide. Infected individuals are often unaware of their condition and as a result, continue to transmit these viruses. Although conventional diagnostic tests exist, in LMIC they are largely inaccessible due to high costs or a lack of trained personnel, resulting in poor linkage to care and increased infections. Timely and accurate diagnosis is needed to achieve elimination of hepatitis B and C by the year 2030 as set out by the World Health Organization Global Health Sector Strategy. In this review rapid diagnostic tests allowing for quick and cost-effective screening and diagnosis of HBV and HCV, are discussed, as are their features, including suitability, reliability, and applicability in LMIC, particularly those within Africa.

Public investments in the development of GeneXpert molecular diagnostic technology

Background

The GeneXpert diagnostic platform from the US based company Cepheid is an automated molecular diagnostic device that performs sample preparation and pathogen detection within a single cartridge-based assay. GeneXpert devices can enable diagnosis at the district level without the need for fully equipped clinical laboratories, are simple to use, and offer rapid results. Due to these characteristics, the platform is now widely used in low- and middle-income countries for diagnosis of diseases such as TB and HIV. Assays for SARS-CoV-2 are also being rolled out. We aimed to quantify public sector investments in the development of the GeneXpert platform and Cepheid’s suite of cartridge-based assays.

Methods

Public funding data were collected from the proprietor company’s financial filings, grant databases, review of historical literature concerning key laboratories and researchers, and contacting key public sector entities involved in the technology’s development. The value of research and development (R&D) tax credits was estimated based on financial filings.

Results

Total public investments in the development of the GeneXpert technology were estimated to be $252 million, including >$11 million in funding for work in public laboratories leading to the first commercial product, $56 million in grants from the National Institutes of Health, $73 million from other U.S. government departments, $67 million in R&D tax credits, $38 million in funding from non-profit and philanthropic organizations, and $9.6 million in small business ‘springboard’ grants.

Conclusion

The public sector has invested over $250 million in the development of both the underlying technologies and the GeneXpert diagnostic platform and assays, and has made additional investments in rolling out the technology in countries with high burdens of TB. The key role played by the public sector in R&D and roll-out stands in contrast to the lack of public sector ability to secure affordable pricing and maintenance agreements.

Injecting network structure determines the most efficient strategy to achieve Hepatitis C elimination in people who inject drugs

Transmission of Hepatitis C (HCV) continues via sharing of injection equipment between people who inject drugs (PWID). Network-based modelling studies have produced conflicting results about whether random treatment is preferable to targeting treatment at PWID with multiple partners. We hypothesise that differences in the modelled injecting network structure produce this heterogeneity. The study aimed to test how changing network structure affects HCV transmission and treatment effects. We created three dynamic injecting network structures connecting 689 PWID (UK-net, AUS-net and USA-net) based on published empirical data. We modelled HCV in the networks and at 5 years compared prevalence of HCV 1) with no treatment, 2) with randomly targeted treatment and 3) with treatment targeted at PWID with the most injecting partnerships (degree-based treatment). HCV prevalence at 5 years without treatment differed significantly between the three networks (UK-net (42.8%) vs. AUS-net (38.2%), p < 0.0001 and vs. USA-net (54.0%), p < 0.0001). In the treatment scenarios UK-net and AUS-net showed a benefit of degree-based treatment with a 5-year prevalence of 1.0% vs. 9.6% p < 0.0001 and 0.15% vs. 0.44%, p < 0.0001. USA-net showed no significant difference (29.3% vs. 29.2%, p = 0.0681). Degree-based treatment was optimised with low prevalence, moderate treatment coverage conditions whereas random treatment was optimised in low treatment coverage, high prevalence conditions. In conclusion, injecting network structure determines the transmission rate of HCV and the most efficient treatment strategy. In real-world injecting network structures, the benefit of targeting HCV treatment at individuals with multiple injecting partnerships may have been underestimated.

Treatment of hepatitis C virus infection

Hepatitis C virus infection affects 71 million people worldwide. It is at the origin of a multi-organ disease associating hepatic manifestations, cryoglobulinemic vasculitis and general manifestations linked to chronic inflammation (diabetes, cardio-, reno- or cerebrovascular manifestations, extra-hepatic cancers including non-Hodgkin's lymphoma). The significant morbidity and mortality linked to the hepatitis C virus therefore justify its screening and access to treatments which have increased considerably over the past two decades. Understanding the replicative cycle of the hepatitis C virus has enabled the development of direct HCV-specific antivirals targeting viral proteins (NS3/4A protease, NS5B polymerase and the multifunctional NS5A replication complex). The combination of two to three specific inhibitors often co-formulated in a capsule, without pegylated interferon and most often without ribavirin, allows high antiviral efficacy (more than 97% cure) for a treatment duration of 8-12 weeks with satisfactory tolerance. HCV infection is the only chronic viral infection that can be cured and the hepatic or extrahepatic manifestations are mainly reversible. This underlines the importance of strengthening screening and access to care policies in order to achieve the elimination of viral infection C in the short term, in 2030, as expected from the program of the World Health Organization. If this elimination is possible in some countries (Iceland, France, Germany …), it seems compromised in others where prevention (USA), screening and/or access to care are still insufficient (Sub-Saharan Africa, Russia…).

Novel Hepatitic C Virus (HCV) Diagnosis and Treatment Delivery Systems: Facilitating HCV Elimination by Thinking Outside the Clinic

The World Health Organization has set a goal to eliminate hepatitis C virus (HCV) infection as public health threat by 2030. Although the advent of highly effective and tolerable direct-acting antiviral therapy has paved the way for HCV elimination, most people with HCV infection remain undiagnosed and untreated globally, with striking disparities between high-income and low- to middle-income countries. Novel decentralized and cost-effective "test-and-treat" strategies are critically needed to identify the millions of people unaware of their status and link them to treatment.

Challenges in the Early Infant HIV Diagnosis and Treatment Cascade

The first step in improving morbidity and mortality among children living with HIV is the timely and early identification of HIV infection, which must be followed by rapid engagement in care and provision of antiretroviral therapy. However, in 2018, only 59% of HIV-exposed infants received an infant nucleic acid diagnostic test by age 2 months and only 54% of children living with HIV received treatment. Because infant diagnosis requires molecular techniques to detect viral nucleic acid, programs for early diagnosis of infection in infants are more complex than those in adults and often require coordination and management of multiple health facilities as well as logistic, financial, and human resource challenges. This article will discuss challenges at each step in the early infant diagnosis cascade and innovations that may help overcome these challenges.

Evaluation of true point of care molecular assay using fingerstick capillary whole blood for diagnosis of hepatitis C infection

At present, the available point of care (POC) molecular assays for hepatitis C are not considered as true POC due to sample collection and processing requiring minimal laboratory infrastructure. A new POC Xpert HCV VL Fingerstick (Xpert FS) precludes such requirements where specimen collected by simple fingerstick can be loaded directly into the test cartridge with results available within 60 min. The present study compared the performance of this assay for HCV RNA quantitation using both capillary whole blood (CWB) and venous whole blood (VWB) with plasma HCV RNA performed on Abbott Real Time HCV PCR. CWB via fingerstick and VWB via venipuncture collected from serologically confirmed HCV-infected participants were loaded into Xpert HCV VL WB for viral load estimation. Simultaneously Abbott Real Time HCV PCR assay was also performed using plasma (reference method). Among the enrolled participants (n=157), the mean age was 46.22±14.79 years and 63 % were male. HCV RNA was detected in 100 cases (63.7 %), median 5.69 (IQR: 5.00-6.32)log₁₀IU ml^-1 on the reference method. Xpert FS showed 100 % sensitivity and specificity using both CWB and VWB. The median viral loads detected in CWB and VWB were 5.52 (IQR: 4.59-6.15) and 5.48 (IQR: 4.61-6.07)log₁₀IU ml^-1, respectively. Xpert FS offers potential as true POC enabling accurate diagnosis in a single patient visit to the health-care facility, hence may reduce the number of dropouts with a confirmed diagnosis. However, further real-time studies with larger sample size are warranted.

Hepatitis C standards of care: A review of good practices since the advent of direct-acting antiviral therapy

Significant steps must be taken to reduce the global incidence and prevalence of hepatitis C virus (HCV) and mortality from HCV infection to achieve the WHO goal of eliminating viral hepatitis as a public health threat by 2030. Proper epidemiological surveillance of the full continuum of care is essential for monitoring progress and identifying gaps that need to be addressed. The tools required for elimination have largely been established, and the issue at hand is more how they should best be implemented in different settings around the world. Documenting good practices allows for knowledge exchange to prevent transmission and improve health outcomes for people with HCV. This review found 13 well documented HCV good practices that have become the standard of care or that should become the standard of care as soon as possible. In 2013, highly effective direct-acting antiviral therapy became available, which has cure rates of over 95%. Together with this new therapy, evidence-based good practices can help countries eliminate viral hepatitis C.

Evaluation of the Xpert HCV VL Fingerstick point-of-care assay and dried blood spot HCV-RNA testing as simplified diagnostic strategies among people who inject drugs in Catalonia, Spain

BACKGROUND

Catalonia requires decentralized and simplified strategies for the diagnosis of viremic HCV infection among people who inject drugs (PWID). We aimed to perform a direct comparison of the diagnostic performance between two, single-step strategies for the screening and diagnosis of viremic HCV infection in PWID attending a drug consumption room (DCR) in Barcelona: i) on-site HCV-RNA testing using the point-of-care test (PoCT) Xpert HCV VL Fingerstick; and ii) on-site dried blood spots (DBS) collection for HCV-RNA testing at the laboratory (in-house assay). Additionally, we aimed to assess participants' preferences in receiving HCV-RNA testing results and feasibility of same-day delivery of PoCT results.

METHODS

The real-world, clinical performance of these two strategies was established in comparison with the reference method (HCV viral load testing with the Xpert HCV Viral Load assay at the laboratory from venous plasma collected at the DCR). HCV genotypes/subtypes and HIV status were also determined by sequencing and serology, respectively. A questionnaire including preferences regarding the delivery of test results was administered.

RESULTS

The prevalence of HCV-RNA was 63.0% (of which 25.8% were co-infected with HIV). The RNA-PoCT showed a sensitivity of 98.4% for detectable viral loads (>4 IU/mL) and of 100% for quantifiable viral loads (≥10, ≥1000 and ≥3000 IU/mL). For the DBS-based assay, a sensitivity of 93.7% was obtained for detectable viral loads, 96.7% for the quantifiable ≥10 IU/mL threshold, and 98.3% for both the quantifiable ≥1000 and ≥3000 IU/mL thresholds. No significant differences were detected between the sensitivity values of these two strategies, and the specificity was 100% in both cases. Half of the participants preferred to receive the HCV-RNA result on the same day, and 80% of participants received their RNA-PoCT results on the same day.

CONCLUSIONS

Both the HCV-RNA PoCT and the DBS-based assay are highly reliable tools for the simplified diagnosis of viremic HCV infection among current PWID. These strategies allow for on-site sample collection and delivery of test results, facilitating decentralized care in harm reduction services.

Assessing Molecular Point-of-Care Testing and Dried Blood Spot for Hepatitis C Virus Screening in People Who Inject Drugs

Background

Injecting drug use is a major driver of hepatitis C virus (HCV) spread worldwide, and the World Health Organization (WHO) has identified people who inject drugs (PWID) as a key population to target for HCV screening and care. Point-of-care (POC) hepatitis C tests and dried blood spot (DBS) sampling offer benefits for the management of patients with HCV infection by increasing HCV testing and linkage to care in different nonclinical settings. The aims of this prospective study were to evaluate the feasibility and the acceptability of use HCV ribonucleic acid (RNA) POC and fingerstick DBS testing in social-medical risk-reduction centers and to describe the cascade of care among PWID in France.

Methods

Between June 2018 and February 2019, 89 consecutive HCV-seropositive PWID attending 2 drug treatment services and 1 supervised consumption room in inner Paris were invited to participate in further evaluation, undergoing a clinical review with a liver assessment and blood tests including fingerstick capillary whole blood POC HCV RNA testing and fingerstick DBS sampling.

Results

Of the 89 participants enrolled, HCV RNA was detected in 34 (38.6%) participants. Fingerstick whole blood POC RNA testing and HCV RNA detection from DBS sample were feasible and acceptable among PWID with no major difference in terms of HCV RNA detection rate. Overall, 16 participants received pan-genotypic antiviral treatment. The proportion of PWID with sustained virologic response at 12 weeks was 81.2%, with data for 3 patients still pending.

Conclusions

One-step screening strategy based on the detection of HCV RNA would engage people in care for treatment scale-up and HCV elimination.

In-field evaluation of Xpert® HCV viral load Fingerstick assay in people who inject drugs in Tanzania

BACKGROUND

Although novel hepatitis C virus (HCV) RNA point-of-care technology has the potential to enhance the diagnosis in resource-limited settings, very little real-world validation of their utility exists. We evaluate the performance of HCV RNA quantification using the Xpert® HCV viral load Fingerstick assay (Xpert® HCV VL Fingerstick assay) as compared to the World Health Organisation pre-qualified plasma Xpert® HCV VL assay among people who inject drugs (PWID) attending an opioid agonist therapy (OAT) clinic in Dar-es-Salaam, Tanzania.

METHODS

Between December 2018 and February 2019, consecutive HCV seropositive PWID attending the OAT clinic provided paired venous and Fingerstick samples for HCV RNA quantification. These were processed onsite using the GeneXpert® platform located at the Central tuberculosis reference laboratory.

RESULTS

A total of 208 out of 220 anti-HCV-positive participants recruited (94.5%) had a valid Xpert® HCV VL result available; 126 (61%; 95% CI 53.8-67.0) had detectable and quantifiable HCV RNA. About 188 (85%) participants had paired plasma and Fingerstick whole blood samples; the sensitivity and specificity for the quantification of HCV RNA levels were 99.1% and 98.7% respectively. There was an excellent correlation (R2  = .95) and concordance (mean difference 0.13 IU/mL, (95% CI -0.9 to 0.16 IU/mL) in HCV RNA levels between plasma samples and Fingerstick samples.

CONCLUSION

This study found excellent performance of the Xpert® HCV VL Fingerstick assay for HCV RNA detection and quantification in an African-field setting. Its clinical utility represents an important watershed in overcoming existing challenges to HCV diagnosis, which should play a crucial role in HCV elimination in Africa.