Emergence of HCV genotype 6 and its new variants among intravenous drug users in Manipur, a north-eastern state of India.

BACKGROUND

Manipur, a north-eastern state of India, has a high incidence of intravenous drug use with an equally high prevalence of Hepatitis C virus (HCV) infection.

OBJECTIVES

This cross-sectional study aimed to evaluate the impact of certain risk factors enhancing the susceptibility of acquiring HCV.

DESIGN

A total of 1008 participants from various risk groups, from nine districts across the state, were enrolled. Blood samples along with demographic data were collected from the study participants.

METHODS

HCV RNA was isolated and nested RT-PCR was performed followed by Sanger sequencing for genotyping. Phylogenetic and phylogeographic studies were further conducted.

RESULTS

Of the total, 493 (48.90%) samples were HCV sero-reactive. Among the sero-reactive samples, 406 (82.35%) were HCV RNA positive. In case of the subgroup PWID + HIV, sero-reactivity (82.22%) and viremia (90.54%) were observed to be exceptionally high. It was noted that HCV sero-reactivity increased four times in people living with HIV (PLHIV) who continued to inject drugs. Three HCV genotypes and eight subtypes were circulating in this study population.

CONCLUSION

In PLHIV who continued to inject drugs, HCV sero-reactivity increased four-fold. About 40% of the population living with HCV belonged to genotype 6, while genotype 1 showed a noticeable decline. Phylogeographic analyses and spatiotemporal reconstructions revealed that most of the subtypes migrated from far south-east Asian countries like Thailand, Malaysia, Myanmar, and Singapore.