Abstract：
Legionella is an opportunistic waterborne pathogen that is difficult to eradicate in colonized drinking water pipes. Legionella control is further challenged by aging water infrastructure and lack of evidence-based guidance for building treatment. This study assessed multiple premise water remediation approaches designed to reduce Legionella pneumophila within a residential building located in an aging, urban drinking water system over a two-year period. Samples (n = 745) were collected from hot and cold-water lines and quantified via most probable number culture. Building-level treatment approaches included three single heat shocks, three single chemical shocks, and continuous low-level chemical disinfection in the potable water system. The building was highly colonized with L. pneumophila with 71 % L. pneumophila positivity. Single heat shocks had a statistically significant L. pneumophila reduction one day post treatment but no significant L. pneumophila reduction at one week, two weeks, and four weeks post treatment. The first two chemical shocks resulted in statistically significant L. pneumophila reduction at two days and four weeks post treatment, but there was a significant L. pneumophila increase at four weeks following the third chemical shock. Continuous low-level chemical disinfection resulted in statistically significant L. pneumophila reduction at ten weeks post treatment implementation. This demonstrates that in a building highly colonized with L. pneumophila, sustained remediation is best achieved using continuous low-level chemical treatment.
摘要：
军团菌是一种机会性的水传播病原体，很难在定植的饮用水管道中根除。老化的水基础设施和缺乏基于证据的建筑物治疗指导，军团菌控制受到进一步挑战。这项研究评估了多种前提水修复方法，旨在减少位于老化的住宅建筑物内的嗜肺军团菌，城市饮用水系统为期两年。从热水和冷水管线收集样品(n=745),并通过最可能的数量培养进行定量。建筑物级处理方法包括三种单一的热冲击，三个单一的化学冲击，以及在饮用水系统中进行持续的低水平化学消毒。该建筑物被嗜肺乳杆菌高度定植，嗜肺乳杆菌阳性率为71％。单次热休克在治疗后一天有统计学意义的肺炎杆菌减少，但在一周内没有明显的肺炎杆菌减少。两周,治疗后四周。前两次化学休克导致治疗后2天和4周有统计学意义的肺炎支原体减少。但在第三次化学休克后4周，嗜肺乳杆菌显著增加。持续的低水平化学消毒在治疗实施后十周导致统计学上显著的嗜肺乳杆菌减少。这表明，在一个高度定植有嗜肺乳杆菌的建筑物中，持续修复最好使用连续低水平化学处理来实现。
