背景及目的：慢性B型及C型肝炎感染是我國肝病相關死亡的二大原兇，因為B型肝炎的有效防治，相對地突顯出C型肝炎的重要性。國內C型肝炎基本流行病學資料，遠較B型肝炎不完整；過去有關台灣各地區C型肝炎的盛行率文獻僅止於是一些片段的社區研究資料，尚未有任何縣市全面性的B型及C型肝炎篩檢的資料曾被發表。本研究的目的在於探討台南縣B型及C型肝炎以村里層級為單位的B型肝炎表面抗原(Hepatitis B surface antigen, HBsAg)、C型肝炎抗體(Anti-hepatitis C virus antibody, anti-HCV)盛行率及ALT(alanine transaminase)異常率，並分析整個台南縣各村里間地理區域的差異性。材料及方法：台南縣衛生局於2004年4月至11月期間在全縣31個鄉鎮市的533個村里舉辦216場「行動醫院」。邀請四十歲以上居民（n=56702；男／女：17551/39151）來參加以全民健保成人健檢為主體的多項篩檢，其中包括HBsAg、anti-HCV及ALT三項檢驗。ALT以40 IU/L為正常的上限值。我們以標凖化罹病比(standardized morbidity ratio; SMR)來分析整個台南縣各村里的B、C型肝炎陽性率及ALT異常率分佈的狀況，方法是以各村里的B、C型肝炎陽性率及ALT異常率除以台南縣整體的B型肝炎、C型肝炎陽性率及ALT異常率。並以卡方適合度檢定方式來檢定其與參考值是否有無顯著的差異。有13個村里因收案人數太少不滿足做卡方檢定的基本條件而不納入本研究分析。結果，全縣HBsAg陽性率、anti-HCV陽性率及ALT的異常率各為10.9%、10.2%及12.8%。村里B型肝炎陽性率以官田鄉嘉南村28.0%(7/25)最高，而七股鄉看坪村、安定鄉中榮村、西港鄉金砂村及龍崎鄉石嘈村四個村里0%為最低。SMR≧2且顯著高於參考值的有9個村里，而SMR＜0.5且顯著低的有21個村里。C型肝炎陽性率，以東山鄉水雲村90.5%(38/42)為最高，而永康市神州里等12個村里0%為最低。SMR≧2且顯著高於參考值的有69個村里，其中有8個村里陽性率大於50%以上，而SMR<0.5且顯著低的則有118個村里，盛行率很高或很低的村里的數目都比B型肝炎多很多。村里ALT異常率最高的是東山水雲村54.8%(23/42)，其次為南溪村41.0%(18/44)，而以大洲村（新市）0.0%(0/53)為最低。SMR≧2且顯著高於參考值的有15個村里，而SMR<0.5且顯著低的則有18個村里，顯著高及顯著低的地區大致與C型肝炎類似。各鄉鎮市的村里C型肝炎盛行率相當多樣化，有僅少數村里高者亦有全鄉鎮皆高的。結論：本研究提供台南縣全縣各村里別的完整資料，並描繪出各種不同的聚集形式，為重要的公共衛生資訊。

Background and Aims: Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are the two major causes of liver disease deaths in Taiwan. The impact of HCV infection has increased since the effective prevention of HBV infection. Epidemiologic studies of HCV, in comparison with HBV, have hither to been incomplete in Taiwan. Previous studies for the prevalence of HCV were limited to small-scale community studies, and no large-scale community studies for the screening of HBV and HCV have been published before. The purpose of this study is to investigate the prevalence of HB surface antigen (HBsAg), anti-HCV antibody (anti-HCV) and hypertransaminemia levels in villages in Tainan county, and to analyze geographic variations among villages throughout the whole county. Patients and Methods: Health examinations were carried out by the Health Bureau of Tainan County in 533 villages in Tainan county between April and November 2004. Residents aged >40 years (n=56702; men/women: 17551/39151) were invited for a series of examinations, including HBsAg, anti-HCV and alanine transaminase (ALT). The upper normal limit of ALT levels is 40 IU/L. Standardized morbidity ratio (SMR) was used to analyse prevalences of HBsAg, anti-HCV and hypertransaminemia in village levels of Tainan county. The method is prevalences of HBsAg, anti-HCV and hypertransaminemia in village levels were divided by overall prevalences of these three parameters respectively. Goodness-of-fit test for chi-square was used to test the significance difference between the prevalences. A total of 13 villages were excluded because the number of subjects enrolled was not sufficient for the chi-square test. Results: The overall prevalence of HBsAg, anti-HCV and hypertransaminemia was 10.9%, 10.2% and 12.8% respectively. In village-specific prevalences of HBsAg, the highest prevalence was in Jianan village (Guantian Township) (28.0%, 7/25), and the lowest prevalences were found in Kanping village (Cigu Township), Chungjung village (Anding Township), Chinsha village (Sigang Township) and Shichao village (Longci Township) , (all at 0%). There were nine villages with significant levels of SMR (≧2), and 21 villages with significant levels of SMR (<0.5). For anti-HCV, the highest prevalence was in Shuiyu village (Dongshan Township) (90.5%, 38/42), where as a total of 12 villages had 0% prevalence. There were 69 villages with statistically significant levels of SMR (≧2) and 8 villages which had prevalence rates of more than 50%. 118 villages had significant levels of SMR (<0.5). The numbers of high or low prevalence of HCV was much greater than for HBV. In prevalence of hypertransaminemia, the highest prevalence was in Shuiyu village (Dongshan Township) (54.8%, 23/42), followed by Nanhsi village (41.0%, 18/44). The lowest prevalence was in Tachou village (Hsinshih Township) (0%, 0/53). There were 15 villages with significant levels of SMR (≧2), and 18 villages with significant levels of SMR (<0.5). The distributions of high and low prevalence of hypertransaminemia were similar to the prevalence of anti-HCV. Prevalence of anti-HCV at village level showed great diversity among each township. There was a high prevalence of anti-HCV in only a few villages in a township, but there were also all villages in a township. Conclusions: This study provides complete data for HBV, HCV and hepatitis in every village in Tainan County, and describes their geographic variations and distribution patterns. This important information should prove important to workers in public health.