The genetic diversity and evolutionary history of hepatitis C virus in Vietnam

- We characterized both Core-E1 and NS5B sequences of HCV from 236 Vietnamese.
- We detected 13 subtypes plus two novel variants as a new subtype candidate.
- They represent multiple indigenous lineages and several alien strains.
- We estimated the epidemic history for four major subtypes: 1a, 1b, 6a, and 6e.
- They all showed rapid HCV growth corresponding to the era of the Vietnam War.

Vietnam has a unique history in association with foreign countries, which may have resulted in multiple introductions of the alien HCV strains to mix with those indigenous ones. In this study, we characterized the HCV sequences in Core-E1 and NS5B regions from 236 Vietnamese individuals. We identified multiple HCV lineages; 6a, 6e, 6h, 6k, 6l, 6o, 6p, and two novel variants may represent the indigenous strains; 1a was probably introduced from the US; 1b and 2a possibly originated in East Asia; while 2i, 2j, and 2m were likely brought by French explorers. We inferred the evolutionary history for four major subtypes: 1a, 1b, 6a, and 6e. The obtained Bayesian Skyline Plots (BSPs) consistently showed the rapid HCV population growth from 1955 to 1963 until 1984 or after, corresponding to the era of the Vietnam War. We also estimated HCV growth rates and reconstructed phylogeographic trees for comparing subtypes 1a, 1b, and HCV-2.