| Abstract: | 肝炎是我們的國病，肝癌更是列名國內十大死因的前茅，因此肝炎的防治是衛生機構最重要的課題之一。C型肝炎病毒的感染是在台灣地區肝病猖獗僅次於B型肝炎的根源，此些根源是爾後發生肝硬化乃至肝癌最重要者，自從衛生署全面推廣B型肝炎疫苗預防注射後，即大大降低B型肝炎的感染率及帶原率，但C型肝炎目前並未有疫苗預防接種，因此對於C型肝炎流行的情況之研究，尤其是C型肝炎病毒感染途徑方面的探討，以期加以切斷，並希望能了解其致病機轉及自然過程之情形，是為迫切需要。許多的研究顯示：學齡前孩童若受到感染，會有很高的比率變成慢性之顯性或不顯性肝炎，因此對於該年齡層的研究探討有其必要性。而引發肝炎的病毒常見者除B及C型肝炎外，尚有A及E型肝炎等，其中E型肝炎在國內鮮有報告，尤其是台灣中部地區的孩童。因此我們特從中部地區五個縣市的各公私立幼稚園，以多步驟抽樣法在市鎮中心與郊鄉地區各篩檢兩所幼稚園，每所幼稚園依大、中、小班，各隨機抽樣一班，每所約抽樣一百名孩童，每個縣市各約四百名合計約兩千多名孩童，另外增加南投縣信義鄉及仁愛鄉原住民全部的幼稚園孩童為選樣對象共484名，總計有2538名學齡前兒童及他們的老師為抽樣對象。每位孩童皆經由家長立同意書後，從靜脈採血取得血清，以自動化儀器測試肝功能指標：丙胺酸轉胺 (alanine aminotransferase, ALT) 值；以及以酵素免疫分析法 (ELISA) 檢查C及E型肝炎免疫抗體等，然後再結合同意書中的各項資料進行分析。研究資料以SPSS軟體系統做統計分析，並以多變項迴歸分析法鑑定其對比值 (OR) 及95% 信賴區間 (CI) 值，且利用卡方檢定法進行危險因子與感染率的相關性分析；調整干擾因素後之顯著性檢定，則以Mantel-Haenszel卡方檢定法進行之；多變項的分析則以對數複迴歸模式進行之。從上述資料分析所得結果：歸類出臺灣中部地區學齡前孩童C及E型肝炎的血清盛行率，並試圖進行了解其感染途徑；以及學齡前之低年齡層孩童肝功能指標值的狀況，裨益衛生機構對肝炎的防治與宣導，更進而擬訂衛教與截斷感染源的措施。
C型肝炎流行病學方面：有58位孩童是C型肝炎抗體陽性，佔2.3% (58/2538)，原住民孩童則是1% (5/484)，經由多變項分析調整後，與其他氏族比較有明顯低的差異。男孩的C型肝炎抗體盛行率比女孩高，但未達統計學上的差異 (ORm：1.6；95% CI：0.9-2.8；p = 0.08)，3-4歲年齡層的盛行率比5-6歲低 (ORm：2.2；95% CI：1.1-4.2；p = 0.02)。經由多變項調整分析後，具C型肝炎抗體盛行率的孩童且受B型肝炎病毒自然感染的比未被感染的要高，但未達統計學上的差異 (ORm：2.6；95% CI：0.9-7.4；p = 0.08 for HBV-infected vs. uninfected)。在台灣，C型肝炎病毒的感染與B型肝炎病毒自然的感染，除了性別與居住地外，應該還有更多的共同傳染途徑存在。另外，為數不少的本省居民相信醫療注射比口服治療要快，尤其是對孩童的醫療，因此間接造成C型肝炎病毒之感染的增加。
E型肝炎流行病學方面：共有86位孩童是E型肝炎抗體陽性者，佔3.4% (86/2538)，原住民孩童是3.9% (19/484)，與其他氏族群比較起來，有高的差異 (OR：1.68；95% CI：1.56-2.95；p < 0.05)。女孩的E型肝炎抗體盛行率比男孩高 (OR：1.55；95% CI：1.14-2.54；p < 0.05)。原住民孩童的E型肝炎抗體隨年齡的增加而上昇 (X2 for trend = 5.59, p = 0.02)，但非原住民孩童則隨年齡的增加而下降。在台灣原住民的地區，自來水的缺乏以及下水道的污染，野生動物的頻繁接觸與生活環境的條件貧瘠，衛生習慣與觀念，在在都顯示與E型肝炎病毒感染的關係。
Taiwan is a hyperendemic area of hepatitis B virus (HBV) infection where chronic hepatitis B is the most important cause of liver cirrhosis and hepatoma. Since of diagnostic kit for detecting hepatitis C virus (HCV) infection has been developed, HCV was found to be another important etiology of chronic liver disease. In order to study the seroprevalence of HCV infection among preschool children after mass hepatitis B vaccination program in Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas, and 2 aboriginal areas randomly selected through stratified sampling. Serum specimens of 2,538 preschool children were screened for the HCV antibodies (anti-HCV) by a commercially available third-generation microparticle enzyme immunoassay and for HBV markers by radioimmunoassay methods and for HEV antibodies (anti-HEV) by a commercially available enzyme immunoassay. The multivariate-adjusted odd ratios (ORm) with their 95% confidence intervals (CI) were estimated through the multiple logistic regression analysis. A total of 58 children were anti-HCV seropositive, giving a prevalence of 2.3%. The prevalence of anti-HCV was 1.0% (5 of 484) among aboriginal children, a significantly decreased seroprevalence compared with those among other ethnic groups after multivariate adjustment. Boys had a higher anti-HCV seroprevalence, but not statistically significantly different from girls (ORm: 1.6; 95% CI: 0.9-2.8; p = 0.08). The seroprevalence of the age group of 3-4 years was lower than that of the age group of 5-6 years (ORm: 2.2; 95% CI: 1.1-4.2; p = 0.02). After multivariate adjustment, preschool children with natural HBV infection had a higher anti-HCV seroprevalence, but not statistically significantly different from those without natural HBV infection (ORm: 2.6; 95% CI: 0.9-7.4; p = 0.08 for HBV-infected vs. uninfected). HCV infection varies with gender, residential area, and natural HBV infection. HCV and HBV might share common transmission routes in Taiwan.
A total of 86 children were anti-HEV seropositive, giving a prevalence of 3.4%. The prevalence of anti-HEV was 3.9% (19 of 484) among aboriginal children, a significantly increased seroprevalence compared with that among children lived in urban areas (OR: 1.68; 95% CI: 1.56-2.95; p <0.05). Females had a higher anti-HEV seroprevalence than the males (OR: 1.55; 95% CI: 1.14-2.54; p < 0.05). Rates of carry of anti-HEV antibody increased with age in aboriginal areas (X2 for trend = 5.59, p = 0.02), but decreased with age in non-aboriginal areas. The poor water supply system, poor sewage disposal, exposure to wild animals, and other environmental conditions in the aboriginal areas might have played a role in their infection with HEV in Taiwan. |
