Seroprevalence of Hepatitis A among Children and Young Adults Residing in Tehran, Iran: Implication for HAV Vaccination

Background: Hepatitis A virus (HAV) is a major cause of acute viral hepatitis throughout the world. The severity of HAV clinical symptoms in infected cases is related to age. Age - specific seroprevalence studies are a reliable method to estimate the susceptibility rate to HAV in populations and can help establish vaccination implementation policies. Objectives: In this study we aimed to determine the age - specific HAV seroprevalence among 1 to 23 years subjects residing in Tehran, Iran. Methods: In this cross - sectional study, blood samples of 1120 cases (516 male and 604 female) referred to hospitals’ biochemical laboratories in Tehran, Iran, between the ages of 1 - 23 years were tested for total hepatitis A antibody (anti - HAV) by ELISA. Stratification of the study population was conducted according to age. Results: The overall prevalence of total anti - HAV was 6% (95% CI: 4.74% - 7.52%). HAV prevalence rates according to age groups were as follows: 5.7% between 1 - 5 years, 1.7% between 6 - 10 years, 4.2% between 11 - 15 years, 5.5% between 16 - 19 years, and 15.3% between 20 - 23 years. Except the 6 - 10 year age group, an increase in HAV seropositivity was observed with age. Anti - HAV seropositivity in terms of age groups was significantly different from each other (P = 0.000). The HAV seroprevalence rate was 32.8% in males and 67.2% in females with a significant difference between genders (P = 0.025). Conclusions: Our study demonstrates that most young children are susceptible to HAV infection, whereas adolescents and young adults are at more risk for HAV acquisition. Therefore HAV vaccination of young children seems logic and beneficial.