Whole-genome characterization and resistance-associated substitutions in a new HCV genotype 1 subtype

Prevalence of Hepatitis C Virus Infection, Genotypes and Subtypes in Migrants from Pakistan in Barcelona, Spain

Background

Hepatitis C virus (HCV) is a major cause of chronic liver infection with 71 million people infected worldwide. Pakistan has the second highest prevalence of HCV infection and more than half (52%) of Pakistani living in Spain reside in Barcelona. The aim of this study was to analyse the seroprevalence and viraemic rate and determine the genotypes and subtypes of HCV among Pakistanis living in the southern metropolitan area of Barcelona.

Methods

We included all Pakistani patients seeking primary healthcare in the southern metropolitan area of Barcelona from August 2011 to July 2014. Serum samples were screened for HCV antibodies. HCV viral load was determined by reverse transcription polymerase chain reaction and genotypes and subtypes were performed using Versant HCV Genotype and/or deep-sequencing. Screening for hepatitis B virus (HBV) was also carried out.

Results

Among 5877 Pakistani patients, 565 (9.61%) were screened for anti-HCV antibodies, with 68 (12.04%) being positive. The viral load was determined in 65, with 31 presenting active infection and the viraemic rate was 47.69% (95% confidence interval 36.02-59.62). HCV genotyping and subtyping were performed in 24 individuals. Most infections corresponded to HCV genotype 3 (91.67%), and high resolution HCV subtyping was performed in 18 samples, 16 of which presented subtype 3a. One subject presented HBV coinfection with undetectable HBV DNA. During the study period, we identified a possible case of HCV vertical transmission followed by spontaneous viraemia clearance in a chronically infected mother with a C/T IL28B genetic polymorphism.

Conclusion

These results suggest that general HCV screening protocols in patients from high prevalence countries, such as Pakistan, would be helpful to identify and treat active HCV infections. This could avoid further transmission and contribute to building targeted health policies for micro-elimination of HCV infection in specific communities.