Hepatitis A immunity in Yozgat, Turkey

BACKGROUND: Since routine immunization could change the epidemiological profile of hepatitis A virus (HAV) infection in the future, it is important to determine the baseline immunity to HAV across Turkey. OBJECTIVE: The aim of this study was to determine the seroprevalence of hepatitis A among individuals 6 years of age and older in Yozgat, Turkey. DESIGN: Cross-sectional. SETTING: Community in central region of Turkey. PATIENTS AND METHODS: Questionnaires and blood specimens were collected and the presence of hepatitis A IgG antibodies against hepatitis A virus was determined quantitatively by ELISA. MAIN OUTCOME MEASURES: The rates of hepatitis A immunity by age group. SAMPLE SIZE: 1862. RESULTS: Immunity to hepatitis A was 79.1% (n=1473). The mean (SD) age was 17.1 (14.7) years in the nonimmune group and 37.8 (19.5) years in the immune group (P<.001), and immunity increased with age. No significant difference in immunity rate was detected between genders in children and adults. The seropositivity rate for subjects ages 6–19 years was lower than in subjects aged 20–96 years (52.2% versus 93.9%; P<.001). CONCLUSION: A catch-up vaccination program is needed for persons aged 6–19 years in Yozgat. LIMITATIONS: Single region data which can not be generalized. For this reason, a multi-centered study that can reflect the whole country is recommended.