Distribution of hepatitis B infection in Brazil: the epidemiological situation at the beginning of the 21 st century.

Francisco José Dutra Souto

doi:10.1590/0037-8682-0176-2015

Abstract

Brazil was formerly considered a country with intermediate hepatitis B endemicity, with large heterogeneity between Brazilian regions and areas of high prevalence, especially in the Amazon basin. Systematic vaccination of children was initiated in 1998. Between 2004 and 2009, a large population-based study reported decreased prevalence in all regions of Brazil. This review analyzed the current hepatitis B epidemiological situation in Brazil through a systematic search of the scientific literature in MEDLINE, LILACS, and CAPES thesis database, as well as disease notifications to the Information System for Notifiable Diseases. The search strategy identified 87 articles and 13 theses, resulting in 100 total publications. The most recent results indicate reduced hepatitis B prevalence nationwide, classifying Brazil as having low endemicity. Most studies showed HBV carrier prevalence less than 1%. However, there are still isolated regions with increased prevalence, particularly the Amazon, as well as specific groups, such as homeless people in large cities and isolated Afro-descendant communities in the center of the country. This review alsao detected successful vaccination coverage reported in a few studies around the country. The prevalence of anti-HBs alone ranged from 50% to 90%. However, isolated and distant localities still have low coverage rates. This review reinforces the downward trend of hepatitis B prevalence in Brazil and the need to intensify vaccination strategies for young people and adults in specific regions with persisting higher HBV infection prevalence.

Highlights

Hepatitis B is a viral infectious disease responsible for significant worldwide human morbidity and mortality
The World Health Organization (WHO) classifies hepatitis B endemicity according to the prevalence of the serological marker of viremia, the hepatitis B surface antigen (HBsAg)(3)
After reviewing the titles and abstracts, studies referring to aspects other than the prevalence or incidence of hepatitis B were discarded, as well as those that focused on subpopulations with increased risk for hepatitis B virus (HBV) infection, such as patients with human immunodeficiency virus (HIV), patients in renal replacement therapy, poly-transfused patients, patients with chronic liver disease or scleral jaundice, or patients with sexually transmitted diseases

Summary

Introduction

Hepatitis B is a viral infectious disease responsible for significant worldwide human morbidity and mortality. This disease burden is due mainly to complications of chronic infections, such as liver cirrhosis and hepatocellular carcinoma(1) (2). The hepatitis B virus (HBV) is transmitted person-to-person through contact with blood, exudates, and other body fluids such as semen and vaginal secretions. Iatrogenic dissemination was a common route of transmission throughout the second half of the 20th century due to blood product transfusion and sharing or reuse of syringes and needles, natural routes of transmission are mainly responsible for the high disease prevalence, including sexual, vertical (perinatal, from mother to newborn), and horizontal transmission from environmental exposure in the home, prisons, and other confinement institutions. The WHO currently categorizes endemicity as low, intermediate low, intermediate high, or high (Table 1)

Methods

Results

Conclusion