Introduction
Currently, there are around 240 million chronic carriers of HBsAg around the world, which are at the highest risk of developing chronic liver diseases such as primary liver cirrhosis and hepatocelular carcinoma (Aparna Schweitzer, 2015). Most countries in Latin America and the Caribbean (LAC) are classified as low endemic areas, but there are some high endemicity spots as well (Díez-Padrisa & Castellanos., 2013). One of the most extensively studied high endemic areas in LAC is the Amazon basin, an area that is shared by Brazil, Colombia, Venezuela, Peru, and Ecuador. In the pre-vaccine era, the prevalence of HBsAg among adults was above 7%-26%, especially in rural areas, and there were frequent outbreaks of fulminant hepatitis …show more content…
Epidemiology of hepatitis B was extensively studied in the pre-vaccine era, but by contrast there are only three studies published so far describing it after vaccine introduction (Braga, 2012) (Cabezas-Sánchez, 2014) (De la Hoz F P. L., 2008). Furthermore, these studies have produced conflicting results. Braga et al 2012, found a low effectiveness of HBV vaccination, around 30%, while De la Hoz et al and Cabezas et al reported a substantial reduction of HBsAg carriage and HBV infection in the post-vaccine …show more content…
In 2001, it changed to a schedule composed of a birth dose, with a monovalent vaccine, and three subsequent doses using a pentavalent vaccine (DTP+Haemophilus influenza type b (Hib)+HBV). In 1999, a serological survey study found a reduction of ≈ 70% in HBV infection and HBsAg carriage among children of urban and rural areas in the Colombian Amazon state despite health services´ struggle to provide timely access to HBV vaccine for rural population (De la Hoz F P. L.,
Currently, there are around 240 million chronic carriers of HBsAg around the world, which are at the highest risk of developing chronic liver diseases such as primary liver cirrhosis and hepatocelular carcinoma (Aparna Schweitzer, 2015). Most countries in Latin America and the Caribbean (LAC) are classified as low endemic areas, but there are some high endemicity spots as well (Díez-Padrisa & Castellanos., 2013). One of the most extensively studied high endemic areas in LAC is the Amazon basin, an area that is shared by Brazil, Colombia, Venezuela, Peru, and Ecuador. In the pre-vaccine era, the prevalence of HBsAg among adults was above 7%-26%, especially in rural areas, and there were frequent outbreaks of fulminant hepatitis …show more content…
Epidemiology of hepatitis B was extensively studied in the pre-vaccine era, but by contrast there are only three studies published so far describing it after vaccine introduction (Braga, 2012) (Cabezas-Sánchez, 2014) (De la Hoz F P. L., 2008). Furthermore, these studies have produced conflicting results. Braga et al 2012, found a low effectiveness of HBV vaccination, around 30%, while De la Hoz et al and Cabezas et al reported a substantial reduction of HBsAg carriage and HBV infection in the post-vaccine …show more content…
In 2001, it changed to a schedule composed of a birth dose, with a monovalent vaccine, and three subsequent doses using a pentavalent vaccine (DTP+Haemophilus influenza type b (Hib)+HBV). In 1999, a serological survey study found a reduction of ≈ 70% in HBV infection and HBsAg carriage among children of urban and rural areas in the Colombian Amazon state despite health services´ struggle to provide timely access to HBV vaccine for rural population (De la Hoz F P. L.,