Hepatitis C virus (HCV) infection is a global health problem and approximately 80% of the patients develop chronic hepatitis C, which can progress to liver cirrhosis and hepatocellular carcinoma. HCV genotype is a classical predictor of the success of the standard treatment (interferon-α in combination with ribavirin). HCV genotype 1 carriers have usually a lower rate of response than patients infected with HCV genotypes 2 and 3.1 Human single nucleotide polymorphisms near the gene for interferon-λ3 (IFNL3; formerly known as IL28B) were also recently associated with spontaneous HCV clearance and sustained response to interferon-based therapy.2 The present study aimed to determine the frequency of the HCV and IFNL3 genotypes in hepatitis C patients from the North region of Rio Grande do Sul state, Southern Brazil.

Adult individuals with chronic hepatitis C attended in referral services for patient care in Passo Fundo (a medium-sized urban center in the North region of Rio Grande do Sul state) were selected from August 2010 to July 2011. Socio-demographic data were obtained from a structured questionnaire and patient medical records were reviewed to obtain clinical and virological information. IFNL3-molecular analysis was performed as previously described.2 The study was approved by the Research Ethics Committee of the Universidade Luterana do Brasil (ULBRA).

A total of 191 HCV-infected patients were included in the study. Patients were predominantly female (52.9%) and had a mean age of 51.6±11.4 years. Approximately half of the participants (n=92, 48.2%) received blood transfusions and 75 patients (39.3%) reported that this condition was the possible HCV transmission route. Use of sharp objects (26.7%) and needle sharing (17.8%) were also cited as possible transmission factors. HCV genotype 1 was found in 76 (39.8%), genotype 2 in 46 (24.1%) and genotype 3 in 69 patients (36.1%). HCV genotype 1 was significantly more often in users of illicit drugs, while genotype 2 was more frequently found in women and old people. Sixty patients (31.4%) showed the CC, 97 (50.8%) CT and 34 (17.8%) TT IFNL3 genotypes (Table 1).

Some HCV genotypes have a restricted geographical distribution (genotypes 4-6), while others (genotypes 1-3) are more broadly disseminated. HCV genotype 1 is the most prevalent in the world.1 In the present study, genotype 1 was also demonstrated in the highest frequency, followed by genotypes 3 and 2, respectively. Other studies in Brazil have also shown the occurrence of these three genotypes, but genotype 1 with frequencies over 60%, while genotype 2 lower than 10%.3,4 This unusual high frequency of HCV genotype 2 confirms the results observed in a previous study.5 In the present report it was further demonstrated the high proportion of old women infected with this genotype. IFNL3 CC genotype, a good human prognostic factor of treatment outcome, was also found in a percentage similar to other Brazilian study.2

In conclusion, the data obtained in the present study have shown a high frequency of HCV genotype 2 in an urban center in Southern Brazil and suggest the HCV genotypes could have different transmission routes.