AI Insight
Researchers used whole genome sequencing of hepatitis A virus (HAV) samples to investigate outbreaks in Massachusetts and New Hampshire in 2018 and a subsequent outbreak in Massachusetts in 2023. Despite similar demographic profiles and risk factors among affected individuals, genomic analysis confirmed the two outbreak periods were caused by distinct viral strains. The study identified homelessness and prior drug use as factors associated with increased transmission, while also revealing cross-risk-group transmission and spread across state lines.
Why it matters
These findings demonstrate that genomic epidemiology can meaningfully complement traditional outbreak investigations by clarifying transmission chains and identifying drivers that may not be apparent from epidemiological data alone, ultimately helping public health authorities design more targeted interventions for vulnerable populations.
⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
Despite the existence of an effective vaccine, the United States continues to experience outbreaks of hepatitis A, including in Massachusetts (MA) and New Hampshire (NH) in 2018 and again in MA in 2023. To clarify the relationship between these outbreaks and better understand their drivers, we generated hepatitis A virus whole genome sequences from reported cases and analyzed them using open-source genotyping tools developed and released as part of this study. We found that the 2018 and 2023 outbreaks were caused by distinct viral strains, despite affecting individuals with similar demographic characteristics and reported risk factors. Detailed analysis of genomic and epidemiologic data further resolved transmission patterns within and across outbreaks, showing that experiencing homelessness and prior use of drugs were associated with increased transmission while also revealing transmission between individuals with and without these risk factors, as well as spread across state borders. Together, these findings demonstrate the value of broadly accessible genomic tools for understanding hepatitis A outbreaks and illustrate how whole genome analysis can complement epidemiological investigation by resolving transmission patterns and outbreak drivers that can inform public health interventions.