目標：本文收集2000年至2005年共8590位被通報疑似退伍軍人症患者之檢體進行確認，並整理分析其結果，以勾繪出臺灣退伍軍人菌之現況。方法：收集疑似肺炎之患者檢體，依照美國CDC指引，分析患者血清、尿液和痰液檢體。血清檢體進行間接免疫螢光抗體試驗，尿液檢體檢測嗜肺性退伍軍人菌第一型抗原，痰液檢體進行微生物培養及鑑定。結果：8590位患者中，有428位疑似肺炎患者被証實為感染退伍軍人症，其陽性率為5.0%。性別比例方面，男性有305位 (71.3%)，女性有123位 (28.7%)。年齡分布方面，大於65歲以上的有230位 (53.7%)，佔最多數，而14歲以下為0。季節分布方面，一年四季發病率都一樣高。地理分布方面，每10萬人口發生率 (Incidence rate) 以在花蓮縣最高為(5.46)，其次為臺東縣 (0.89)、臺北縣 (0.35)、高雄市 (0.33)和苗栗縣 (0.30)。但以送檢率相對調整後，每10萬人口調整發生率p值無顯著差異。結論：在臺灣退伍軍人症的確定病例陽性率從2000年至2005年平均約5.0%。因此菌培養不易，本實驗室經改進培養方法，將陽性培養率0%提高至15.8%。其中以Legionella pneumophila佔87.9%，又以Legionella pneumophila serogroup 1佔63.6%為最主要菌種，此結果與其它國家相似。

Objective: Our purpose was to determine the distribution of legionellosis (LG) in Taiwan. Methods: Specimens from 8,590 LG-suspected patients were collected and analyzed during the period 2000–2005. Following Centers for Disease Control (USA) guidelines, serum, urine, and sputum specimens were assessed by the indirect immunofluorescence antibody test, Legionella pneumophila type 1 antigen test, and Legionella isolation, respectively.Results: LG was diagnosed in 428 pneumonia patients (305 [71.3%] male and 123 [28.7%] female), and the LG positive rate among pneumonia patients in Taiwan was calculated to be 5.0% (428/8,590). Most LG patients 230 (53.7%) were age ?65, while none were ?14. No seasonal differences in LG incidence rate were detected. Incidence rates (per 100,000 patients) were highest in Hualien county (5.45), followed by Taiton county (0.89), Taipei county (0.35), Kauosiun city (0.33), and Mialee county (0.30).Conclusions: The LG incidence rate among pneumonia patients in Taiwan was 5.0% from the year 2000 to 2005. Owing to modification of the isolation technique in this study, the isolation rate for Legionella increased from 0% during 2000-2001 to 15.8% in 2005. Furthermore, Legionella pneumophila (87.9%) was the most frequently isolated species in Taiwan, and Type 1 (63.6%) was its most prevalent serogroup. This result is similar to results from other countries.