Optimizing diagnostic algorithms to advance Hepatitis C elimination in Italy: A cost effectiveness evaluation

Comparison of a hepatitis C core antigen assay to nucleic acid amplification testing for detection of hepatitis C viremia in a US population

The prevalence of hepatitis C virus (HCV) infection in the United States has increased over the past decade despite the development of effective direct-acting antiviral treatments. To meet the World Health Organization's (WHO) goal of eliminating HCV infection by 2030, transmission events must be reduced. Currently, infection screening relies on detection of HCV antibodies, with nucleic acid amplification testing (NAAT) used to confirm HCV viremia and monitor changes in viral load. However, the seroconversion window for detection of HCV antibodies is long, averaging 6 weeks, with delayed seroconversion common in co-infected and immunosuppressed populations. Testing for HCV core antigen, which is present approximately 5 weeks before HCV antibodies, holds promise for earlier detection of HCV infection. It may also hold promise as a cheaper, more accessible, and more rapid alternative to NAAT for infection confirmation. Here, we evaluated the agreement between a research-use HCV Core Antigen Assay and NAAT among US patients receiving clinically indicated NAAT. Among 412 specimens, the overall concordance was 97.1%, with a positive percent agreement of 95.5%. Discrepancies primarily occurred among patients with chronic HCV and low viral loads; 11/12 discrepancies showed viral loads <4,000 IU/mL. Among patients being screened for HCV infection (i.e., excluding those undergoing NAAT for serial monitoring of a previously diagnosed infection), the positive percent agreement was 97.0%. Among patients undergoing serial testing, changes in HCV Core Antigen Assay signal-to-cut-off values were generally correlated with changes in the viral load. Results suggest that the research-use HCV Core Antigen Assay studied here may reliably detect and/or confirm HCV infection.

IMPORTANCE

A research-use HCV Core Antigen Assay showed high concordance with nucleic acid amplification testing for the detection of current hepatitis C infection. The assay may enable more rapid and lower-cost detection and/or confirmation of hepatitis C infection.

We have reached single-visit testing, diagnosis, and treatment for hepatitis C infection, now what?

INTRODUCTION

Progress toward hepatitis C virus (HCV) elimination is impeded by low testing and treatment due to the current diagnostic pathway requiring multiple visits leading to loss to follow-up. Point-of-care testing technologies capable of detecting current HCV infection in one hour are a 'game-changer.' These tests enable diagnosis and treatment in a single visit, overcoming the barrier of multiple visits that frequently leads to loss to follow-up. Combining point-of-care HCV antibody and RNA tests should improve cost-effectiveness, patient/provider acceptability, and testing efficiency. However, implementing HCV point-of-care testing programs at scale requires multiple considerations.

AREAS COVERED

This commentary explores the need for point-of-care HCV tests, diagnostic strategies to improve HCV testing, key considerations for implementing point-of-care HCV testing programs, and remaining challenges for point-of-care testing (including operator training, quality management, connectivity and reporting systems, regulatory approval processes, and the need for more efficient tests).

EXPERT OPINION

It is exciting that single-visit testing, diagnosis, and treatment for HCV infection have been achieved. Innovations afforded through COVID-19 should facilitate the accelerated development of low-cost, rapid, and accurate tests to improve HCV testing. The next challenge will be to address barriers and facilitators for implementing point-of-care testing to deliver them at scale.

Comparison of effectiveness and cost of different HCV testing strategies in high-risk populations in China

High-risk populations are the predominant populations affected by hepatitis C virus (HCV) infection, and there is an urgent need for efficient and cost-effective HCV testing strategies for high-risk populations to identify potential undiagnosed HCV-infected individuals. This study compared several commonly used testing strategies and conducted effectiveness and cost analysis to select the appropriate testing strategy for diagnosing HCV infection in high-risk populations. Among the 2093 samples from high-risk populations in this study, 1716 were HCV negative, 237 were current HCV infection, 137 were past HCV infection, and three were acute early HCV infection. It was found that out of 237 patients with HCV current infection, Strategy A could detect 225 cases, with a missed detection rate of 5.06%, and the total cost was 33 299 RMB. In addition, Strategy B could detect 237 cases of current HCV infection, and the HCV missed detection rate was 0.00%, and the total cost was 147 221 RMB. While 137 cases of past HCV infection could be distinguished by strategy C, but 14 cases with current HCV infection were missed, with an HCV-positive missed detection rate of 5.91%, and the total cost for Strategy C was 43 059 RMB. In conclusion, in high-risk populations, the HCV positivity rate is typically higher. If feasible, the preferred approach is to directly conduct HCV RNA testing, which effectively minimizes the risk of missing cases. However, in situations with limited resources, it is advisable to initially choose a highly sensitive method for anti-HCV screening, followed by HCV RNA testing on reactive samples.

Anti-HDV reflex testing in HBsAg-positive subjects: An efficacious strategy to identify HDV infection

BACKGROUND AND AIMS

The prevalence of HDV infection in HBsAg carriers is about 9.9% in Italy. However, the real prevalence is underestimated because the anti-HDV test is not performed routinely in all HBsAg carriers. The aim of this study was to compare the prevalence and the absolute number of HDV infection identified in HBsAg-positive subjects tested at University Hospital Federico II before and after the introduction of anti-HDV reflex testing.

METHODS

From January to December 2022, reflex test for the detection of total HDV antibodies was performed in all HBsAg-positive subjects tested at University Hospital Federico II. The control group consisted of all the HBsAg-positive subjects tested at the same laboratory in 2019, before the implementation of anti-HDV reflex testing. Sera were evaluated with ADVIA Centaur HBsAgII Qualitative, Liaison Murex HBsAg Quantitative and Liaison Murex Total Anti-HDV Qualitative.

RESULTS

Before reflex testing, anti-HDV had been tested in 16.4% (84/512) of HBsAg-positive subjects, while after its implementation, 100% (484/484) of HBsAg-positive patients was tested for anti-HDV. The anti-HDV positive prevalence was lower than before the introduction of reflex test (10.7% vs. 16.6%) but the absolute number of anti-HDV positive patients increased (14 vs. 52 subjects). HDV-RNA was detectable in 26 (53%) of 49 tested subjects.

CONCLUSIONS

Our data showed that the implementation of anti-HDV reflex testing increased the diagnoses of HDV infection. In this setting, due to the approval of specific anti-HDV drugs, a reflex test for anti-HDV should be implemented to early identify patients with HBV/HDV infection.

Exploring Knowledge and Awareness of HCV Infection and Screening Test: A Cross-Sectional Survey Among an Italian Sample

Addressing HCV represents a public health priority, especially in Italy, which has the highest HCV prevalence in Europe. This study primarily aimed to explore knowledge about the HCV infection and awareness of the existence of the HCV screening test in Italy, before the implementation of awareness campaigns in 2022. An online cross-sectional survey was conducted (December 2021-January 2022). The primary outcomes were: Disease Knowledge Score (DKS), Prevention and Transmission Knowledge Score (PTKS) (for both: scoring from 0 to 100%, higher scores corresponded to higher knowledge), and being unaware of the existence of the HCV screening. The final sample consisted of 813 participants. The median DKS was 75% (IQR = 66.7-83.3), the median PTKS was 46.2% (IQR = 38.5-53.8), and 23.2% of participants were unaware of HCV screening. Higher education, health-related study or profession, history of accidental injuries, being affected by HCV and having actively searched for information on HCV had positive associations with DKS. LGBT males showed significantly lower DKS. Considering PTKS, participants affected by HCV the disease had a negative association with this score. Having a postgraduate education reduced the likelihood of not knowing about the HCV screening test, while having at least one family member affected by hepatitis C increased this probability. This study highlighted a concerning lack of knowledge about prevention and transmission, indicating a need for targeted education campaigns. The findings emphasized the importance of information and motivation and identified male LGBT + individuals as a vulnerable group with limited disease knowledge. Future research should concern the effectiveness of awareness campaigns.

Hepatitis C Virus Micro-Elimination Plan in Southern Italy: The "HCV ICEberg" Project

This study evaluates the feasibility of a local action program for HCV micro-elimination in highly endemic areas. Retrospective analysis: administrative and laboratory data (Local Health Unit, southern Italy) were integrated to quantize the anti-HCV-positive subjects not RNA tested and untreated HCV-infected subjects (2018-2022). Prospective analysis: all subjects admitted to a division of the LHU largest hospital (2021-2022) were tested for HCV, with linkage of active-infected patients to care. Overall, 49287 subjects were HCV-Ab tested: 1071 (2.2%) resulted positive without information for an HCV RNA test and 230 (0.5%) had an active infection not yet cured. Among 856 admitted subjects, 54 (6.3%) were HCV-Ab+ and 27 (3.0%) HCV RNA+. Of HCV-infected patients, 22.2% had advanced liver disease, highlighting the need for earlier diagnosis; 27.7% were unaware of HCV infection; and 20.4% were previously aware but never referred to a clinical center. Of these, 26% died and 74% received treatment. Our study emphasizes the value of an active HCV hospital case-finding program to enhance diagnosis in patients with several comorbidities and to easily link them to care. Our data strongly suggest extending this program to all hospital wards/access as a standard of care, particularly in highly endemic areas, to help HCV disease control and take steps in achieving the elimination goals.

Elimination of Hepatitis C in Southern Italy: A Model of HCV Screening and Linkage to Care among Hospitalized Patients at Different Hospital Divisions

Background: Free-of-charge HCV screening in some key populations and in 1969-1989 birth cohorts has been funded in Italy as the first step to diagnosing individuals who are infected but asymptomatic. The aim of this study is to evaluate the feasibility of an opportunistic HCV screening and its linkage to care. Methods: A hospital-based HCV screening was conducted as a routine test for in-patients admitted to the Evangelical Hospital Betania of Naples from January 2020 to May 2021. All consecutive in-patients were screened for the HCV antibody (HCV-Ab) at the time of their admission to the hospital, and those born prior to year 2000 were included in the study. HCV-RNA testing was required for those not previously treated and without antiviral treatment contraindications. For in-patients with an active infection, treatment started soon after hospital admission. Results: Among 12,665 inpatients consecutively screened, 510 (4%) were HCV-Ab positive. The HCV-Ab positivity rate increased with age, reaching the highest prevalence (9.49%) in those born before 1947. Among patients positive for HCV, 118 (23.1%) had been previously treated, 172 (33.9%) had been discharged before being tested for HCV-RNA, and 26 (5.1%) had not been tested for short life expectancy. Of 194 (38% of HCV-Ab+) patients who were tested for HCV-RNA, 91 (46.2%) were HCV-RNA positive. Of patients with active infection, 33 (36%) were admitted to the liver unit with signs of liver damage either not previously diagnosed or diagnosed but unlinked to care for HCV infection. Of the patients positive for HCV-RNA, 87 (95.6%) started treatment; all achieved sustained virological response. Conclusion: HCV active infection has been frequently found in patients with comorbidities admitted in the hospital in Southern Italy. To achieve HCV elimination in Italy, broader screening strategies are required. In addition to screening of the 1969-1989 birth cohort of individuals unaware of their infection status, diagnosis and linkage to care of patients with known liver damage is strictly required. Hospital screening is feasible, but prompt reflex testing for identifying HCV-active infections is necessary to increase diagnosis and subsequent linkage to care.