The seroepidemiological investigation of HAV among the population aged from 1 to 15 years in HAV outbreak areas in Yili Prefecture

Objective The present investigation was made to find out the relationship between HAV antibody levels and the prevalence of hepatitis A in order to provide more warning informa-tion for the HAV control and prevention．Methods The serum of the children at the age of 1-15 in the regions where there had been an HAV outbreak were collected from October to December in 2005．The anti-HAV test was done and then analysed．Results 885 persons were tested in all，623 of whom were anti-HAV positive。Thus，the prevalence rate of anti-HAV was 70.40％，which was significantly higher than that before the HAV outbreak in this region (the prevalence rate of anti-HAV was 40.00％)．The prevalence rate had a trend to increase with the age，besides，it had differences between the different nationalities．Conclusion Among children aged 1-15 years，if the prevalence rate of anti—HAV is lower than 40.00％．It iS likely for HAV Outbreak or preva- lence to occur．In contrast，the probability is greatiy reduced when the rate is higher than 70.00％．Therefore，it is necessary to launch the HAV vaccination in the children under the age of 15 SO as to raise their anti—HAV levels．