Geographical distribution of HCV genotypes in Mexico

Chronic hepatitis C (CHC) is the second cause of endstage liver disease in our country and one of the main indications of liver transplantation. Hepatitis C virus (HCV) genotype is the principal prognostic factor and the determinant of the therapeutic scheme. In our country few data exist regarding the prevalence of HCV infection and genotype distribution in the Mexican Republic has not been determined. The aim of this study was to characterize the prevalence of the different HCV genotypes and to explore their geographical distribution. Methods: Mexican patients with hepatitis C infection, detected throughout the country between 2003 and 2006, were included. All samples were analyzed by a central laboratory and Hepatitis C genotype was identified by Line Immuno Probe Assay in PCR positive samples (Versant® Line Probe Assay Quest Diagnostics Nichols Institute, San Juan Capistrano CA). Data were analyzed according to the four geographical areas in Mexico. Results: One thousand three hundred and ninety CHC patients were included. The most frequent genotype detected was genotype 1 (69%) followed by genotype 2 (21.4%) and genotype 3 (9.2%). Genotype 4 and 5 were infrequent. There was no subject infected with genotype 6. Genotype 1 and 2 exhibit very similar distribution in all geographical areas. Genotype 3 infected patients were more frequent in the North region (52%) compared with other areas: center-western (30%), center (17%), South-South east (1%) (p < 0.001). Conclusions: The most prevalent HCV genotype in Mexico is genotype 1. Geographical distribution of HCV genotypes in the four geographical areas in Mexico is not homogenous with a greater frequency of genotype 3 in the north region. This difference could be related to the global changes of risk factors for HCV infection.