Farrell I D, Barker J E, Miles E P, Hutchison J G
Regional Public Health Laboratory, East Birmingham Hospital.
Epidemiol Infect. 1990 Jun;104(3):381-7. doi: 10.1017/s0950268800047397.
The colonization, survival and control of Legionella pneumophila in a hospital hot-water system was examined. The organism was consistently isolated from calorifier drain-water samples at temperatures of 50 degrees C or below, despite previous chlorination of the system. When the temperature of one of two linked calorifiers was raised to 60 degrees C, by closing off the cold-water feed, the legionella count decreased from c. 10(4) c.f.u./l to an undetectable level. However, 10 min after turning on the cold-water feed which produced a fall in calorifier temperature, the count in the calorifier drain water returned to its original level. Investigations revealed that the cold-water supply was continually feeding the calorifiers with L. pneumophila. Simple modifications in the design of the system were made so that the cold-water feed no longer exceeds 20 degrees C; these measures have considerably reduced the number of L. pneumophila reaching the calorifiers.
对医院热水系统中嗜肺军团菌的定殖、存活及控制情况进行了研究。尽管该系统先前已进行过氯化处理，但在温度为50摄氏度或更低的情况下，始终能从热交换器排水样本中分离出这种微生物。当通过关闭冷水供应将两个相连热交换器中的一个温度升至60摄氏度时，军团菌数量从约10⁴ c.f.u./l降至检测不到的水平。然而，开启冷水供应导致热交换器温度下降10分钟后，热交换器排水中的菌数又恢复到原来的水平。调查发现，冷水供应持续为热交换器输送嗜肺军团菌。对系统设计进行了简单修改，使冷水供应温度不再超过20摄氏度；这些措施已大幅减少了进入热交换器的嗜肺军团菌数量。
