Assessing the rate of non-linkage to care and identifying barriers in individuals living with hepatitis B. Results of the LINK-B study

BACKGROUND & AIMS

Hepatitis B infection is the most frequent cause of chronic hepatitis and liver cancer worldwide. Active searching for individuals with chronic hepatitis B has been proposed as a strategy to achieve the elimination of this virus. The primary aim of this study was to link to specialists HBsAg-positive individuals detected in a laboratory database and to characterize individuals who were not linked to care.

METHODS

We performed a retrospective-prospective evaluation of all HBsAg-positive serum samples identified in the central laboratory of the Northern Barcelona area between January 2018 and June 2022. After reviewing the patients' clinical charts, all those not linked to care were given an appointment with a specialist.

RESULTS

Medical records of 2765 different HBsAg-positive serum samples were reviewed and 2590 individuals were identified: 844 (32.6%) were not linked to a specialist, 653 were candidates for linkage, and 344 attended the specialist visit. The two main reasons why they were not under specialist care were administrative issues, such as living in another region (12.1%) and lacking contact details (4.1%), and low life expectancy (2.8%). Individuals who did not attend their scheduled visit were mainly young [38.1 ± 12.9 vs. 44.0 ± 14.0 (p < .001)], non-White European [75.3% vs. 58.1% (p < .001)] and men [70.7% vs. 56.4% (p < .001)].

CONCLUSIONS

One in every three HBsAg-positive individuals in our setting was not currently under specialist care. Of particular note, half of them had never attended a specialist consultation, an essential step for evaluating the disease and starting therapy in some countries.

In-Host HEV Quasispecies Evolution Shows the Limits of Mutagenic Antiviral Treatments

Here, we report the in-host hepatitis E virus (HEV) quasispecies evolution in a chronically infected patient who was treated with three different regimens of ribavirin (RBV) for nearly 6 years. Sequential plasma samples were collected at different time points and subjected to RNA extraction and deep sequencing using the MiSeq Illumina platforms. Specifically, we RT-PCR amplified a single amplicon from the core region located in the open-reading frame 2 (ORF2). At the nucleotide level (genotype), our analysis showed an increase in the number of rare haplotypes and a drastic reduction in the frequency of the master (most represented) sequence during the period when the virus was found to be insensitive to RBV treatment. Contrarily, at the amino acid level (phenotype), our study revealed conservation of the amino acids, which is represented by a high prevalence of the master sequence. Our findings suggest that using mutagenic antivirals concomitant with high viral loads can lead to the selection and proliferation of a rich set of synonymous haplotypes that express the same phenotype. This can also lead to the selection and proliferation of conservative substitutions that express fitness-enhanced phenotypes. These results have important clinical implications, as they suggest that using mutagenic agents as a monotherapy treatment regimen in the absence of sufficiently effective viral inhibitors can result in diversification and proliferation of a highly diverse quasispecies resistant to further treatment. Therefore, such approaches should be avoided whenever possible.

LINK-B: study protocol of a retrospective and prospective project for identification and linkage to care of people living with hepatitis B in a large health area of Barcelona

INTRODUCTION

An estimated 290 million people are living with hepatitis B virus (HBV) worldwide; in Spain, the prevalence of hepatitis B virus surface antigen (HBsAg) is 0.4%. In our setting, many HBsAg-positive individuals are not linked to care, which implies a barrier to receiving treatment and controlling the infection. The main objective of this project is to evaluate the performance of a programme designed to achieve appropriate linkage to specialist care of HBsAg-positive individuals, newly tested or previously tested and lost to follow-up.

METHODS AND ANALYSIS

This is a retrospective and prospective study in which all HBsAg-positive cases recorded in the microbiology database will be identified. The retrospective phase will include cases detected between 2018 and 2020, and the prospective phase will run from January 2021 to June 2022. The project will be carried out in a tertiary university hospital covering the northern health area of Barcelona with a catchment population of 450 000 inhabitants and 16 affiliated primary care centres. The central laboratory detects approximately 1200 HBsAg-positive individuals every year; therefore, we expect to identify around 4000 patients over the duration of the project. The medical records of HBsAg-positive individuals will be consulted to identify and retrieve those who have not been appropriately linked to care. Candidates will be contacted to offer specialist disease assessment and follow-up. A website will be created to provide HBV-related information to primary care physicians, and a mobile phone application will be available to patients to improve the linkage circuits and ensure follow-up continuity.

ETHICS AND DISSEMINATION

The Vall d'Hebrón Hospital Ethics Committee (PR(AG)201/2021) and the Spanish Agency of Medicines and Medical Devices approved this study. The findings will be disseminated through peer-reviewed publications and conference presentations. This programme could increase the number of HBsAg-positive individuals properly linked to care and achieve better HBV monitoring, which will have a positive impact on WHO's viral hepatitis elimination goals.