Hepatitis A virus age-specific seroprevalence after the implementation of a Toddlers’ Vaccination in Turkey: Shifting susceptibility to adolescents

AIM: In Turkey, improvements in sanitation and the implementation of a vaccination program resulted in reduced rates of childhood exposure to hepatitis A virus. The incidence of symptoms and the complications of the disease are known to be increased in later ages. We aimed to describe changes in the seroprevalence of hepatitis A virus from the pre-vaccine era (2012) to the post-vaccine era (2018) in different age groups. MATERIAL AND METHODS: Levels of anti-hepatitis A virus immunoglobulin (Ig)-G of patients with no chronic disease and who were admitted to our hospital between 2013–2018 were obtained retrospectively from a single children’s hospital database system. RESULTS: A total of 3238 subjects were enrolled in the study (2820 children, 418 adults). The overall percentage of seropositivity was 60.5% in group 1 (age ≤2 years), 57.9% in group 2 (age 2–6 years), 31.2% in group 3 (age 7–11 years), 32.7% in group 4 (age 12–18 years), 44.6% in group 5 (age 19–24 years), and 73.9% in group 6 (age >25 years). Between 2013–2018, the increase in the number of seropositive individuals in group 2 (p<0.01), and the decrease in groups 3 and 4 were statistically significant from 2013 to 2018 (p=0.028, p<0.01). CONCLUSION: According to the data of this single-center children’s hospital in Turkey, hepatitis A virus seropositivity increases significantly in the preschool age group, but decreases in school-age children and adolescents after vaccination.