Prevalência da infecção e de portadores do vírus da hepatite B, após 19 anos do programa de vacinação na Amazônia ocidental Brasileira

Introduction: Reductions in the prevalence of hepatitis B virus (HBV) infection and carriage, decreases in liver cancer incidence, and changes in patterns of liver dysfunctions are described after hepatitis B vaccination. Methods: We conducted a population-based seroprevalence study aimed at estimating the HBV prevalence and risk of infection in the rural area of Labrea following nineteen years of HBV vaccination. Results: Half of the subjects showed total anti-HBc of 52.1% (95% CI 49.6-54.7). The HBsAg prevalence was 6.2% (95% CI 5.1-7.6). Multivariate analysis showed an inverse association between HBV infection and vaccination (OR 0.62; 95% CI 0.44-0.87). HBsAg remained independently associated with past hepatitis (OR 2.44; 95% CI 1.52-3.89) and inversely to vaccination (OR 0.43; 95% CI 0.27-0.69). The prevalence of HBeAg among HBsAg-positive individuals was 20.4% (95% CI 12.8-30.1), with the positive subjects having a median age of 11 years (1-46) p=0.0003. Conclusions: We demonstrate that HBV infection is still an important public health issue and that HBV vaccination could have had better impact on HBV epidemiology. If we extrapolate these findings to other rural areas in the Brazilian Amazon, we can predict that the sources of chronic infected patients remain a challenge. Future studies are needed regarding clinical aspects, molecular epidemiology, surveillance of acute cases, and risk groups.INTRODUÇÃO: Reduções nas taxas de prevalência de infecção pelo vírus da hepatite B (VHB) e de portadores, incidência de câncer de fígado e mudança nos padrões de doenças hepáticas são descritos, depois da introdução da vacinação contra hepatite B. \ud MÉTODOS: Foi conduzido um estudo de soro prevalência de base populacional, com o objetivo de estimar a prevalência do VHB e fatores de risco de infecção na área rural de Lábrea, depois de 19 anos de introdução da vacinação contra hepatite B. \ud RESULTADOS: Metade dos indivíduos investigados mostrou reatividade ao anti-HBc total, 52,1% (IC 95% 49,6-54,7). A prevalência do HBsAg foi 6,2% (IC 95% 5,1-7,6). Análises multivariadas mostrou associação inversa da infecção pelo VHB e vacinação (OR 0,62; IC 95% 0<44-0,87). A presença do HBsAg permaneceu independentemente associada com o passado de hepatite (OR 2,44; IC 95% 1,52-3,89) e inversamente associado a história de vacinação (OR 0,43; IC 95% 0,27-0,69). A prevalência do HBeAg, entre os HBsAg positivos foi 20,4% (IC95% 12,8-30,1), tendo em média os indivíduos positivos 11 anos de idade (1-46) p=0,0003. \ud CONCLUSÕES: Foi demonstrado que o VHB é ainda um importante problema de saúde publica, e que a vacinação contra o VHB poderia ter tido um impacto maior na epidemiologia do VHB na região. Se esses achados forem extrapolados para outras regiões rurais da Amazônia brasileira, podemos predizer que a fonte de pacientes crônicos é ainda um desafio a ser vencido. Estudos futuros devem focar os aspectos clínicos, a epidemiologia molecular, vigilância de casos agudos e grupos de risco.Fundacao de Amparo a Pesquisa do Estado do Amazonas (FAPEAM)Fundacao de Amparo a Pesquisa do Estado do Amazonas (FAPEAM

Hepatitis D virus infection in the Western Brazilian Amazon - far from a vanishing disease

INTRODUCTION: A decline in hepatitis D virus (HDV) occurrence was described in Europe and Asia. We estimated HDV prevalence in the Brazilian Amazon following hepatitis B vaccination. METHODS: This is a cross-sectional survey of HDV measured by total antibodies to HDV (anti-HD T). RESULTS: HDV prevalence was 41.9% whiting HBsAg carries and was associated with age (PR = 1.96; 95% CI 1.12-3.42; p = 0.01), hepatitis B virus (HBV) infection (PR = 4.38; 95% CI 3.12-6.13; p < 0.001), and clinical hepatitis (PR =1.44; 95% CI 1.03-2.00; p = 0.03). Risk factors were related to HDV biology, clinical or demographic aspects such as underlying HBV infection, clinical hepatitis and age. CONCLUSIONS: Our study demonstrated that HDV infection continues to be an important health issue in the Brazilian Amazon and that the implementation of the HBV vaccination in rural Lábrea had little or no impact on the spread of HDV. This shows that HDV has not yet disappeared from HBV hyperendemic areas and reminding that it is far from being a vanishing disease in the Amazon basin