南部某醫學中心環境，退伍軍人菌消毒作業執行與成效

Implementation and Effect of Environmental Disinfection for Legionella species at A Medical Center in Southern Taiwan

醫療機構環境水系統中退伍軍人菌（Legionella species）的移生具有造成易感病人發生嚴重肺炎的風險，而採取適當的環境消毒方法可避免醫療照護相關感染的產生。本研究目標是為確認兼顧成本與減少退伍軍人病醫療照護相關感染的有效清毒辦法。以環境水系統退伍軍人菌的定期檢測，作為驗證「熱水流放消毒」與「銅銀離子消毒」效果與風險評估的依據，後續以高、低樓層間歇性消毒及以環境水檢測陽性率結果機動調整消毒輪序。以尿液抗原檢測及痰液培養檢測進行退伍軍人病臨床個案評估。消毒成效顯示，銅銀離子法消毒效果良好（2011年消毒前後期間平均陽性率分別為20.0%與0%，p = 0.002），持續性銅銀離子消毒優於間歇性（各作業期間平均陽性率分別為30.5%與51.2%，p = 0.016）。自執行銅銀離子消毒法後即無退伍軍人病醫療照護相關感染個案出現。銅銀消毒停機對陽性率並無影響（有無停機陽性率分別為 5.9%、5%，p = 0.83）。整體結果顯示，應用間歇性銅銀離子消毒，並依檢測結果評估消毒成效，機動性的進行修正、改善，是可同時兼顧成本、消毒成效及醫療照護感染個案控管之方法。

Legionella species in the water environments of healthcare facilities carry a risk of severe pneumonia for susceptible patients. Appropriate environmental disinfection can prevent the occurrence of healthcare-associated legionellosis. The aim of the study was to confirm the effective disinfection method to reduce healthcare-associated legionellosis at a balanced cost. Regular monitoring for Legionella species in water was adopted in this study to further verify the effects of the heat-flush method and copper-silver ionization. After copper-silver ionization was utilized, the disinfection protocol was adjusted based on the results of Legionella positivity in water specimens and the effects of intermittent disinfection for high-floor and low-floor water systems. Urine antigen test and sputum culture test were used to detect clinical cases of Legionnaires' disease. The disinfection effect of copper-silver ionization was excellent, and the Legionella positivity rates of the water samples were 20% and 0% in 2001, before and after the method implementation, respectively (p = 0.002). In terms of copper-silver ionization, the average Legionella positivity rates during its continuous implementation was lower than that during its intermittent use, at 30.5% and 51.2%, respectively (p = 0.016). There was no healthcare-associated case of Legionnaires' disease after the implementation of copper-silver ionization. Moreover, the temporary shutdown of copper-silver ionization disinfection had no effect on the Legionella positivity rate (5.9% vs. 5 %, p = 0.83). The overall results showed that the application of intermittent copper-silver ionization disinfection, with flexible disinfection protocols based on the results of examinations, is a useful method even after taking the cost, the effectiveness, and the control for healthcare-associated infection into consideration.