Hepatitis A seroprevalence in patients with chronic hepatitis B and C at the initiation of treatment

Purpose: Hepatitis A is a vaccine-preventable disease that may follow a more severe course and can lead to fulminant hepatitis in patients with chronic hepatitis. The aim of this study is to determine the seroprevalence of hepatitis A in patients with chronic hepatitis B and C, and to assess the need for hepatitis A vaccination.Materials and methods: A total of 885 adult patients with chronic hepatitis B and C, who had not previously received hepatitis A vaccination and in whom antiviral therapy was initiated between January 2008 and December 2020, were included in the study. Immunity against hepatitis A was assessed at the time of diagnosis by measuring Anti-HAV IgG using the Microparticle Enzyme Immunoassay (MEIA; AxSYM-HAVAB 2.0, ABBOTT) method.Results: The seroprevalence of hepatitis A was 92.7% among 789 patients with chronic hepatitis B and 96 patients with chronic hepatitis C; it was determined to be 94% in patients with chronic hepatitis B and 83% in patients with chronic hepatitis C. While 78% of anti-HAV IgG seronegativity was detected in individuals under 30 years of age, 90% of seronegative cases were under 40. Seropositivity approached 100% in those over 50 years of age; however, a 64-year-old man and a 68-year-old woman with chronic hepatitis C were not immune to hepatitis A.Conclusion: Since hepatitis A superinfection in patients with chronic hepatitis B and C may follow a severe course and lead to a fulminant course, it should be kept in mind that hepatitis A seroprevalence is low, particularly in patients under 30 years of age. However, although the rate decreases with age in adult patients, seronegativity may be detected at any age; therefore, Anti-HAV IgG should be evaluated at the time of diagnosis in all patients with chronic hepatitis, and those found to be negative should be vaccinated against hepatitis A.