High-performance enrichment-based genome sequencing to support the investigation of hepatitis A virus outbreaks

Abstract

Hepatitis A virus (HAV) infections are an increasing public health concern in low-endemicity regions due to outbreaks from food-borne infections and sustained transmission among vulnerable groups, including persons experiencing homelessness, those who inject drugs, and men who have sex with men, which is further compounded by aging, unvaccinated populations. DNA sequence characterization of HAV for source tracking is performed by comparing small subgenomic regions of the virus. While this approach has been successful when robust epidemiological data are available, poor genetic resolution can lead to the conflation of outbreaks with sporadic cases. HAV outbreak investigations would greatly benefit from the additional phylogenetic resolution obtained by whole virus genome sequence comparisons. However, HAV genomic approaches can be difficult because of challenges in isolating the virus, low sensitivity of direct metagenomic sequencing in complex sample matrices like various foods, such as fruits, vegetables, and molluscs, and difficulty designing highly multiplexed PCR primers across diverse HAV genotypes. Here, we introduce a proof-of-concept pan-HAV oligonucleotide hybrid capture enrichment assay from serum and frozen berry specimens that yields complete and near-complete HAV genomes from as few as four input HAV genome copies. We used this method to recover HAV genomes from human serum specimens with high Cτ values (34.7–42.7), with high assay performance for all six human HAV subgenotypes, both contemporary and historical. Our approach provides a highly sensitive and streamlined workflow for HAV whole-genome sequencing from diverse sample types that can be the basis for harmonized and high-resolution molecular epidemiology during HAV outbreak surveillance. IMPORTANCE This proof-of-concept study introduces a hybrid capture oligo panel for whole-genome sequencing of all six human pathogenic hepatitis A virus (HAV) subgenotypes, exhibiting a higher sensitivity than some conventional genotyping assays. The ability of hybrid capture to enrich multiple targets allows for a single, streamlined workflow, thus facilitating the potential harmonization of molecular surveillance of HAV with other enteric viruses. Even challenging sample matrices can be accommodated, making them suitable for broad implementation in clinical and public health laboratories. This innovative approach has significant implications for enhancing multijurisdictional outbreak investigations as well as our understanding of the global diversity and transmission dynamics of HAV.

Hepatitis A virus whole genome sequencing strategy using NGS/Illumina technology

“…Thus, the epidemiology of hepatitis A has transitioned from being an endemic disease, with most of the infections and symptomatic cases during childhood, to causing sporadic outbreaks affecting young adult populations (Fantilli et al, 2023; World Health Organization (WHO), 2023). Consequently, in recent years, there have been reports of foodborne outbreaks, as well as outbreaks and sustained transmission among unvaccinated vulnerable groups, including individuals experiencing homelessness, those who inject drugs, and MSM (Zufan et al, 2024). The combination of infections in older adults and those with comorbidities has led to increase hospitalizations and deaths related to HAV infection, underscoring its emergence as a global public health concern (Mariojoules et al, 2019; World Health Organization (WHO), 2023; Zufan et al, 2024).…”

“…Consequently, in recent years, there have been reports of foodborne outbreaks, as well as outbreaks and sustained transmission among unvaccinated vulnerable groups, including individuals experiencing homelessness, those who inject drugs, and MSM (Zufan et al, 2024). The combination of infections in older adults and those with comorbidities has led to increase hospitalizations and deaths related to HAV infection, underscoring its emergence as a global public health concern (Mariojoules et al, 2019; World Health Organization (WHO), 2023; Zufan et al, 2024).…”

“…However, obtaining WGS is laborious and time-consuming when using the traditional Sanger sequencing technique. On the other hand, NGS methods have emerged as valuable tools for rapidly and efficiently generating complete genome sequences (Batista et al, 2020; Lee et al, 2023; Zufan et al, 2024). Particularly, their relevance was highlighted during the COVID-19 pandemic, when several specialized laboratories had access to this technology enabling the rapid sequencing of complete SARS-CoV-2 genomes for variant surveillance (Hare et al, 2023; Pisano et al, 2022).…”

“…Argentina, after 18 years since the introduction of the vaccine in 1-year-old children in 2005, is now considered a region with low HAV endemicity (Andani et al, 2020). Nevertheless, mirroring global trends, there has been a notable shift in the age distribution of incidence of cases in recent years, with most of them currently occurring among individuals aged 20-36 years (Fantilli et al, 2023; Zufan et al, 2024). Thus, between 2017 and 2018, outbreaks of hepatitis A were documented among MSM both in Argentina and worldwide, highlighting virus circulation despite vaccination efforts (Mariojoules et al, 2019).…”

“…This was notably demonstrated during the COVID19 pandemic, when these techniques were widely employed to study SARS-CoV-2 variants. However, to date, there are few protocols using this technology to rapidly and efficiently generate HAV whole-genome sequences for genotyping and molecular epidemiological tracking (Cleary et al, 2023; Zufan et al, 2024).…”