목적: 최근 20년간 경제적인 발전으로 생활 환경과 위생 상태가 향상되면서 소아에서 A 형 간염 바이러스 감염이 급격히 감소하였다. 이러한 항체 보유율의 감소 추세는 청장년층의 현증 A형 간염의 위험성을 시사하며, 성인에서 고위험군의 예방접종과 함께 소아 예방접종의 필요성이 대두되었다. 본 연구는 소아 및 청소년을 대상으로 A형 간염 항체 보유율과 자연 감염률을 조사하여 이 연령층에서 A형 간염 바이러스 감염 실태 및 예방에 대한 기초 자료를 얻고자 시행하였다. 방법: 경기도에 거주하는 20세 미만의 소아 및 청소년 334명을 대상으로 A형 간염 항 체를 검사하여 연령별 항체 보유율을 조사하였으며, 경기도 소재 4개군(양평, 김포, 파주, 화성)과 4개시(구리, 수원, 부천, 의정부) 초등학교 학생 584명을 대상으로 1993년에 수집한 혈청과 1996년에 수집한 동일인의 혈청을 가지고 A형 간염 항체의 자연 양전률을 조사하였다. 결과: 1) 경기도에 거주하는 20세 미만 334명의 검사 대상자 중 A형 간염 항체 양성은 5.4%였 다. 연령별 항체 보유율은 1세 미만이 27.3%(3/11), 1∼4세가 0.0%(0/8l), 5∼9세가 0.0%(0/57), 10∼14세가 2.9%(3/105), 15∼19세가 15.0%(12/80)로 조사되었다. 2) 경기도 소재 8개 초등학생 584명을 대상으로 A형 간염 항체의 추적 검사를 시행하였 다. 1993년에 1명(0.2%)이 양성이었고 1996년에는 다른 3명(0.5%)이 양성으로 나타나, A형 간염 자연 항체 양전률은 0.5%(3/583)였다. 자연 항체 소실률은 0.2%(1/584)로 조사되었다. 3) 본 연구의 A형 간염 항체 보유율을 1979년과 1989년 조사와 비교하였다. 20세 미만에서 A형 간염 항체 보유율은 1979년에 63.8%, 1989년에 47.3%였으나 1996년에는 5.4%로 감소하였다. 결론: 소아에서 A형 간염 항체의 자연 획득이 거의 일어나지 않는 상황에서는 성인의 현성 감염이 증가할 가능성이 있다. 따라서 우선적으로 A형 간염의 위험성이 높은 지역으로의 여행이나 기타 고위험군을 대상으로 예방접종을 시행할 필요성이 있으며 성인에서의 HAV 감염 기회를 줄이기 위한 방법으로 소아에서의 선별 예방접종도 고려해야 할 것으로 생각된다.

Purpose: The incidence of hepatitis A virus(HAV) infection has markedly decreased in the last 20 years due to industrialization and improvements in the standard of living and hygiene in Korea. The reduction in seroprevalence rates indicates infection potential for young adult population, and a need for vaccinations in high-risk adults and children groups has been suggested. In this study we evaluated the seroprevalence rates and natural infection rates of hepatitis A in children and adolescent to obtain the basic data for vaccination of hepatitis A. Methods: A total of 334 children and adolescent subjects below 20 years old in Kyonggi-do province were examined for HAV antibody and seroprevalence rates in each age group was investigated. In 584 elementary school students residing in Kyonggi-do province, serum samples collected in 1993 and 1996 from the same subjects for investigation of natural seroconversion rates. Method of testing antibody was enzyme immunoassay. Results: 1) The seropositive rate of HAV in 334 subjects aged below 20 years old was 5.4%. According to age, the seropositive rates were 27.3% in infant group, 0.0% in 1¡­4 year-old group, 0.0% in 5¡­9 year-old group, 2.9% in 10¡­14 year-old group and 15.0% in 15¡­19 year-old group. 2) In the study of 584 elementary school children, only one subject showed seropositive in 1993, and in 1996 three different subjects showed seropositive results(0.5%); the natural seroconversion rate during 3 years was 0.5% . 3) The seroprevalence rates of below 20 year-old subjects reported in previous studios were 63.8% in 1979 and 47.3% in 1989 while the present study showed the rate at 5.4%. Conclusion: Since natural antibody formation is rarely occurring, there is a high risk for apparent hepatitis A infection in adults. Therefore vaccination in high risk groups is essential at present, and in order to reduce the chance for hepatitis A infection in adults, vaccination in children may be needed.

Purpose: The incidence of hepatitis A virus(HAV) infection has markedly decreased in the last 20 years due to industrialization and improvements in the standard of living and hygiene in Korea. The reduction in seroprevalence rates indicates infection potential for young adult population, and a need for vaccinations in high-risk adults and children groups has been suggested. In this study we evaluated the seroprevalence rates and natural infection rates of hepatitis A in children and adolescent to obtain the basic data for vaccination of hepatitis A. Methods: A total of 334 children and adolescent subjects below 20 years old in Kyonggi-do province were examined for HAV antibody and seroprevalence rates in each age group was investigated. In 584 elementary school students residing in Kyonggi-do province, serum samples collected in 1993 and 1996 from the same subjects for investigation of natural seroconversion rates. Method of testing antibody was enzyme immunoassay. Results: 1) The seropositive rate of HAV in 334 subjects aged below 20 years old was 5.4%. According to age, the seropositive rates were 27.3% in infant group, 0.0% in 1¡­4 year-old group, 0.0% in 5¡­9 year-old group, 2.9% in 10¡­14 year-old group and 15.0% in 15¡­19 year-old group. 2) In the study of 584 elementary school children, only one subject showed seropositive in 1993, and in 1996 three different subjects showed seropositive results(0.5%); the natural seroconversion rate during 3 years was 0.5% . 3) The seroprevalence rates of below 20 year-old subjects reported in previous studios were 63.8% in 1979 and 47.3% in 1989 while the present study showed the rate at 5.4%. Conclusion: Since natural antibody formation is rarely occurring, there is a high risk for apparent hepatitis A infection in adults. Therefore vaccination in high risk groups is essential at present, and in order to reduce the chance for hepatitis A infection in adults, vaccination in children may be needed.

Hepatitis A, Seroprevalence rate, Vaccination,