Clinical outcome of a patient cohort with acute hepatitis B

Viral hepatitis is a public health problem in Brazil and worldwide. According to the World Health Organization (WHO), 2 billion people have had contact with the hepatitis B virus (HBV); approximately 5% of these individuals are considered carriers (1). The risk of chronicity after infection is 90% in the newborns of mothers with positive hepatitis B early antigen (HBeAg), 25 to 30% in children under 5 years of age, and less than 5% in adults (2). Chronic carriers have an increased risk (15 to 40%) of developing cirrhosis, hepatic decompensation, and hepatocellular carcinoma, resulting in 1 million deaths each year (3). The most effective hepatitis B preventive measure is vaccination. Since 1998, a policy of universal vaccination has been implemented for children younger than 1 year in Brazil. The policy was subsequently extended to people younger than 20 years (4). Vaccination was also extended to vulnerable populations (e.g., injected drug users or healthcare workers) in 2001 and to people up to 29 years of age in 2010 (5). It is estimated that 75% of the under-29 population is vaccinated (6). Because HBV carriers are the source of infection and chronic hepatitis B is a major cause of cirrhosis and hepatocellular carcinoma, it is important to understand the incidence, prevalence, and chronification associated with HBV infection (7). The objective of this study was to describe the clinical outcomes of patients with confirmed acute hepatitis B (AHB) in the South region of Brazil in the city of Porto Alegre from 1999 to 2007.