Distribution of HCV genotypes and HCV RNA viral load in different regions of Mexico.

BACKGROUND AND AIM To identify the geographic distribution of hepatitis C virus (HCV) genotypes and HCV RNA viral load in a large number of HCV-infected carriers in Mexico. METHODS Patients with chronic hepatitis C (n = 8,802) were studied to identify HCV genotype using an immune line probe assay in samples shown previously to be positive for viral RNA by an RT-PCR test. Baseline HCV RNA was also evaluated. RESULTS Genotype 1 accounted for 70.3%, genotype 2 for 21.8%, genotype 3 for 7.2%, genotype 4 for 0.3%, and genotype 5 for 0.1% of all cases; coinfection was present in 0.3%. Overall, Genotype 1 was the most prevalent Genotype. Regionally, genotype 1 occurred more frequently in the North-East, North, and Center- East regions of Mexico; genotype 2 was more prevalent in the South, East, and Peninsula regions; and genotype 3 was more prevalent in the North and North-West regions. Only 22.4% of patients with genotype 1 were classified in the low HCV RNA viral load category, and the distribution of this genotype did not differ significantly between regions. CONCLUSION The prevalence of HCV genotypes and viral load in Mexico was 70.3% for genotype 1, but only 22.4% of these patients had a low HCV viral load. Distribution was not uniform in Mexico, with greater frequency of genotype 2 in South, East and Peninsula Regions and Genotype 3 in North and North-West Regions.