Diverse HCV Strains And HIV URFS Identified Amongst People Who Inject Drugs In India

Although the prevalences of HIV and HCV are significantly higher amongst PWID in India compared to the general population, the strains circulating within this group have not been well-characterized. Through subgenomic sequencing of viruses present in residual plasma from an HIV/HCV prevalence study conducted amongst PWID across five cities in India in 2016–2017, a total of N = 498 HCV and N = 755 HIV strains were classified from N = 975 study participants. Considerable HCV diversity was identified, with different strains predominating in each region of the country. Overall, the most common strain was genotype 3a (39.0%), with genotypes 1a (26.9%), 1b (3.0%), 1c (0.2%), 3b (20.7%), 3i (2.0%), 4a (0.2%), 4d (1.0%), 6 (1.8%), 6n (4.8%), 6 v (0.2%) and one unclassifiable recombinant specimen (0.2%) also identified. The majority of the HIV specimens were subtype C (96.7%), although subtype A (0.4%), CRF01_AE (0.4%) and unique recombinant forms (URFs, 2.5%) were also detected. Notably, the geographical restriction of HIV subtype A and CRF01_AE, and HCV genotypes 4 and 6 to specific sites suggests distinct novel introductions of HIV and HCV into PWID populations, potentially via drug trafficking routes from neighboring countries where these strains are common.