Impacto precoce da vacina universal contra hepatite A no Brasil

Abstract

Introduction: Viral Hepatitis type A (HAV) is mainly transmitted by the fecal-oral route, which presents high prevalence in countries with lower health and socioeconomic conditions. Although hepatitis A is usually a self-limiting, 1-3% of cases can be severe, resulting in fulminant hepatitis, with high morbidity and mortality. There is no specific treatment, being prevention the most important intervention for its control. Brazil introduced universal hepatitis A vaccine in 2014 in a single dose in infants from 12 months to 23 months and was extended up to 5 years in 2017. Objective: To evaluate the early impact of the universal introduction of inactivated Hepatitis A vaccine on incidence, hospitalization, mortality and in confirmed cases of fulminant hepatitis by virus A in Brazil. Method: Retrospective analysis of the national database. The absolute data of hospital admissions for viral hepatitis (CDI-10 B17) in all age groups were analyzed, in the pre-established age groups in the database, in the period of 2004 and 2017. The incidence of hospitalizations for ICD-10 B17 was calculated from the population data base of the Brazilian Institute of Geography and Statistics (IBGE). In addition, data on hospitalization for other diseases were analyzed, and chapter I (Infectious and parasitic diseases) were excluded, when assessing the trends of hospitalizations by other diseases to control factors that would help reduce the number of hepatitis A cases, such as improvements in socioeconomic status and sanitation. Linear regression was performed in a univariate and multivariate model to evaluate statistical significance in reducing the number of hospitalizations. In addition, the mortality and incidence rates of acute hepatitis A in DATASUS database using the ICD-10 B15 (acute hepatitis A) were analyzed. Pre - and post-immunization data were compared. Results: The mean incidence rate of reported cases of hepatitis A decreased to 0.93 per 100,000 population in the period 2015-2017, compared with 3.21 per 100,000 population in the pre-vaccine period (2011-2013). In addition, a reduction of 42.30% was observed in the number of cases of type A fulminant hepatitis in the post-vaccination period. Moreover, a reduction of 74.64% in the number of deaths due to type A acute hepatitis. Multivariate model showed a significant reduction in the number of hospitalizations in the age group vaccinated <5 years. Conclusion: Although it is evaluating an early impact due to the short post-vaccination period, the introduction of the hepatitis A vaccine has a relevant impact on the reduction of cases of hepatitis A, number of deaths, hospitalizations and severe forms of the disease such as fulminant hepatitis, which leads to a reduction in morbidity and mortality.