Different Subtypes of Hepatitis C Virus Genotype 4 are spread among Human Immunodeficiency Virus Coinfected Patients in Argentina

BOLCIC F, JONES L, LAUFER N, QUARLERI J

Boston

Conferencia; 18th Conference on retrovirus and Opportunistic Infections; 2011

Background. HCV genotype 4 (HCV-4) is common in the Middle East and in Africa and has recently spread to several European countries. Its prevalence in Latin America countries is poorly known.  Our aim was to molecularly characterize with further phylogenetic relatedness inference the HCV isolates from HIV-coinfected patients in order to analyze the origin of infection in Argentina. Methods. HCV genotype (Inno-LiPA HCV II, Innogenetics, Belgium) and viral load (Bayer VERSANT® HCV RNA 3.0 Assay) were determined from 383 HIV-HCV-coinfected patients who attended to the CNRS in Buenos Aires, Argentina since May 2009 to May 2010. None was under anti-HCV treatment at the time of sample collection. Age, gender and risk factor of all patients were recorded. The HCV RNA from those isolates characterized as belonging to genotype 4 was amplified and characterized by nucleotide sequencing at NS5B genomic region. Phylogenetic and evolutionary rates by maximum likelihood, parsimony and Bayesian method were estimated. Results. HCV genotype distribution of 383 HIV-coinfected patients was as follows: HCV-1, 73.4% of isolates; HCV-2, 2.1%; HCV-3, 17.5%; HCV-4, 3.7%; mixed genotypes, 3.3%. This result is consistence with the prevalence previously reported in Argentinean HIV-infected patients, except for HCV-4 which increase in 4-folds since 2005 to 2009. The distribution of HCV-4 according to epidemiological characteristics of patients showed statistical differences only against HCV-2 and regarding to viral load against HCV-1. The HCV-4 was found more frequently in men (77.8%) than in women (p>0.01). The HCV-4 subtype inferred by Bayesian analysis, maximum likelihood and parsimony shows that 67% was 4d, 22% was 4a and 1% was 4m. No association was observed between age, gender, risk factor and HCV-4 subtype distribution. Conclusions. HCV-4 circulates in all transmission groups and its presence is increasing among HIV-infected patients in Argentina. These data indicates that all HCV-4 isolates involved different risk groups (sexual transmission and intravenous drug users). Three different HCV-4 subtypes were identified denoting that at least three ways of transmission occurs in HIV-coinfected patients. Future detection of genotype 4 in this area may deserve special attention considering that patients with HCV-4 chronic hepatitis C exhibit a similar rate of response to treatment than genotype 1 patients which is lower than genotype 2 and 3.