退伍軍人症與淋浴

The Relationship between Legionella Infections and Showers

退伍軍人菌普遍存在水體內，並藉由吸入帶菌的空氣微粒而致病。使用蓮蓬頭淋浴，產生的空氣微粒，是醫院內退伍軍人菌可能的傳播方式。原因是醫院蓮 蓬頭，可分離出退伍軍人菌；另有回溯性研究，支持淋浴行為，會增加退伍軍人症及龐帝亞克熱罹病風險。文獻回顧，有關加護病房群聚案例報導鮮少，推測加護病房內臥床病人，不會接受淋浴。但目前淋浴時所曝露的退伍軍人菌量，及人體吸入之致病菌量，還不清楚。

Legionellaceae have been detected in virtually all sources of fresh water, and Legionella infections usually occur through the inhalation of contaminated aerosols. Showering may be one of the modes of transmission of nosocomial legionellosis. Previous studies have revealed that shower heads and domestic hot water systems can be contaminated by Legionella. Furthermore, it has been reported that the possible presence of Legionella in shower aerosols may increase the risk of Pontiac fever and Legionnaires’ disease. Previous reports have documented only a few clusters of legionellosis in intensive care unit settings. This may be attributed to the minimal exposure of bed-ridden intensive care unit patients to Legionella because of the absence of showering among such patients. To date, however, no human studies have quantified the rate of exposure to airborne Legionella via shower aerosols or have established a dose-response relationship. More epidemiological and clinical studies are required to substantiate the rationale of avoiding showering to prevent nosocomial legionellosis.