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World J Gastroenterol. Sep 7, 2013; 19(33): 5446-5453
Published online Sep 7, 2013. doi: 10.3748/wjg.v19.i33.5446
HBV endemicity in Mexico is associated with HBV genotypes H and G
Sonia Roman, Arturo Panduro
Sonia Roman, Arturo Panduro, Department of Molecular Biology in Medicine, Civil Hospital of Guadalajara, “Fray Antonio Alcalde”, and Health Sciences Center, University of Guadalajara, Guadalajara 44280, Jalisco, Mexico
Author contributions: Roman S and Panduro A contributed equally to this paper.
Supported by National Council of Science and Technology (CONACYT-FONDO SECTORIAL, Mexico), Grant No. Salud-2010-1-139085, to Roman S; and Jalisco State Council of Science and Technology (COECYTJAL-Universidad de Guadalajara, Guadalajara, Jalisco, Mexico), Grant No. 2009-1-06-2009-431, to Panduro A
Correspondence to: Arturo Panduro, MD, PhD, Department of Molecular Biology in Medicine, Civil Hospital of Guadalajara, “Fray Antonio Alcalde”, and Health Sciences Center, University of Guadalajara, Guadalajara 44280, Jalisco, Mexico. apanduro@prodigy.net.mx
Telephone: +52-33-36147743 Fax: +52-33-36147743
Received: May 7, 2013
Revised: June 15, 2013
Accepted: July 18, 2013
Published online: September 7, 2013
Processing time: 125 Days and 1.5 Hours
Abstract

Hepatitis B virus (HBV) genotypes have distinct genetic and geographic diversity and may be associated with specific clinical characteristics, progression, severity of disease and antiviral response. Herein, we provide an updated overview of the endemicity of HBV genotypes H and G in Mexico. HBV genotype H is predominant among the Mexican population, but not in Central America. Its geographic distribution is related to a typical endemicity among the Mexicans which is characterized by a low hepatitis B surface antigen seroprevalence, apparently due to a rapid resolution of the infection, low viral loads and a high prevalence of occult B infection. During chronic infections, genotype H is detected in mixtures with other HBV genotypes and associated with other co-morbidities, such as obesity, alcoholism and co-infection with hepatitis C virus or human immunodeficiency virus. Hepatocellular carcinoma prevalence is low. Thus, antiviral therapy may differ significantly from the standard guidelines established worldwide. The high prevalence of HBV genotype G in the Americas, especially among the Mexican population, raises new questions regarding its geographic origin that will require further investigation.

Keywords: Hepatitis B virus genotypes; Hepatitis B virus genotype H; Hepatitis B virus genotype G; Molecular epidemiology; Mexico; Antiviral therapy; Severity of liver disease; Clinical outcome

Core tip: Molecular, clinical, geographical and ethnicity evidence are characteristics that define any hepatitis B virus (HBV) genotype. All of these features are there for HBV genotype H, which is most predominant in Mexico, but not in Central America. Likewise, HBV genotype G has unique molecular characteristics and a similar route of transmission among those infected with this viral genotype, but it lacks a geographic origin. To date, despite the high prevalence of HBV genotype G cases from the Americas, especially among Mexicans, the limited number of complete sequences hinders further investigation to establish a hypothesis of an Amerindian origin.