Variation in Hepatitis C Virus Subtype Distribution during 20 Years in Venezuela

Abstract

Objective: Hepatitis C virus (HCV) infection is a public health problem and a major cause of chronic hepatitis. This virus exhibits a great genetic variability, with 8 genotypes and numerous subtypes. The aim of this study was to evaluate the fluctuations of HCV subtypes during 2 decades in Venezuela. Methods: HCV genotypes were determined by direct sequencing of the 5ʹ-noncoding region in 392 isolates circulating in patients attended during the years 2014–2015. HCV subtype assignment was confirmed in a subset of samples (n = 24) by partial sequencing of the NS5B region. The genotype distribution was compared with the one observed in a previous study of patients followed up during the years 1994–1996 and 2005–2006. Results: Some variation was observed in the HCV genotype distribution over these 20 years. HCV genotype 1b prevalence was reduced significantly from 1994–1995 to 2004–2005, as previously described, and then remained constant. During the last 10 years, a significant decrease of HCV subtype 2b (36/237 in 2005–2006 vs. 24/392 in 2014–2015, p < 0.001) was observed. Patients infected with HCV G2acj were significantly older than the ones infected with G1 (53 vs. 47 years, p = 0.004), and male sex was significantly more prevalent among G3a-infected patients compared to the other ones (71 vs. 47%, p = 0.047). Conclusions: Fluctuations in HCV subtype distribution have been observed over 2 decades in Venezuela. Different major mode of transmission and susceptibility to the available HCV treatment during each period might be playing a role in the observed fluctuations in HCV subtype distribution.