Hepatitis A immunity in Yozgat, Turkey

Abstract

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.