TREND OF ACUTE HEPATITIS A IN THE STATE OF BAHIA, BRAZIL OVER A 5-YEAR PERIOD

ABSTRACT INTRODUCTION: Hepatitis A virus (HAV) has a universal distribution. The prevalence of HAV infection varies greatly according to hygiene and sanitary conditions. OBJECTIVE: To determine the proportion of acute infection of HAV in the state of Bahia during a 5-year period . METHODS: This study was conducted at Central Public Health Laboratory of Bahia (LACEN-BA). All individuals referred for anti-HAV IgM serology from 417 municipalities from January, 2009 to December, 2013 were included.  Percentages of HAV positive cases were presented according to age range for each year of the 5-year study and for each of the nine health districts (RHC) of Bahia. RESULTS: 21,175 samples were analyzed. Proportion of HAV infection was 7.2% (1,535 / 21,175) throughout the study period. The highest proportion was in 2009 (17.4%) and the lowest in 2012 (3.8%), demonstrating a decreasing trend (r = 0.7). The highest infection rates was found in children up to 10 years old. HAV infection was more frequent among males among all age groups. 52.4% (184/351) of the municipalities had acute HAV cases diagnosed. The North and West regions had the highest number of cases. CONCLUSION: There was a progressive decrease of approximately 70% in the proportion of acute HAV infection in the state of Bahia during a five-year assessment period. However, children up to 10 years old remain at higher risk, therefore the vaccine should be expanded to reach this age range.