A study titled “Historical drivers of HCV Subtypes 1b and 3a in Thailand and 6f in Phetchabun, an HCV endemic area of the country” offers new insights into the transmission dynamics of Hepatitis C Virus (HCV) in Thailand. Published in Virus Evolution in 2024, this research examines how historical and social factors contributed to the spread of HCV subtypes 1b, 3a, and 6f, with a special focus on the high-burden region of Phetchabun.

Conducted by researchers from the National Biobank of Thailand, Mahidol University, and Chulalongkorn University, the study used molecular phylogenetic analyses to explore the epidemic history of these viruses. Findings reveal a complex interplay between key historical events and the virus’s spread. Subtype 1b transmission was linked to World War II and suboptimal blood transfusion practices, while the rise of subtype 3a coincided with the intravenous drug epidemic during the Vietnam War. Subtype 6f, primarily found in Phetchabun, was associated with regional political and economic instability in the 1960s-1980s.

Remarkably, despite the different factors driving the viruses’ transmission, their transmission rates appeared to decrease significantly around the same time, between the mid-1990s and early 2000s. The researchers attribute these simultaneous declines to improved healthcare policies in Thailand, particularly enhanced blood transfusion safety, the nationwide “War on Drugs” campaign, broader access to good HCV treatments, and the general greater accessibility to public healthcare.

This work aligns with the World Health Organization’s goal of eliminating viral hepatitis as a public health threat by 2030, making an important contribution toward achieving Sustainable Development Goal 3 (Good Health and Well-being). However, the researchers noted that the prevalence of HCV in Thailand remains high, emphasising the need for further research and a coordinated national strategy to more effectively reduce the HCV burden in the country.

Pakorn Aiewsakun

Co-first author