Molecular epidemiology of acute HCV infection in HIV–positive patients from Hong Kong, Taipei, Tokyo

Abstract Background Acute hepatitis C virus (HCV) infections have been increasingly reported among human immunodeficiency virus (HIV)‐positive men who have sex with men (MSM) in the Asia‐Pacific region. It remains unknown whether international network of HCV transmission has occurred in this region. Methods HIV‐positive patients with acute HCV infection, defined as HCV seroconversion within a year or documented acute hepatitis with seroconversion, diagnosed in Hong Kong, Taipei and Tokyo during 2010‐2016 were included in this molecular epidemiology study. The NS5B region of the HCV genome (365 bp) was amplified using nested polymerase chain reaction and sequenced. Results Of 234 HIV‐positive patients with acute HCV infection, all were male with 94% being MSM. At the diagnosis of acute HCV infection, 73.5% had concurrent sexually transmitted diseases and 88.0% were receiving combination antiretroviral therapy. The most prevalent HCV genotype was 3a, 2a and 1b in Hong Kong, Taipei and Tokyo respectively. Nine independent clusters belonging to five genotypes (1b, 2a, 2c, 3a and 6a) were identified, each of which occurred in one city without overlapping except for one 3a sequence from Taipei that was closely related genetically to the Hong Kong cluster. Conclusions No international network of HCV transmission was identified among HIV–positive patients in the three Asia‐Pacific cities. The transmission dynamics of sexually acquired HCV differed by city, but the risk of intercity clustering should not be ignored.