2023年中南某市夏季公共场所嗜肺军团菌污染状况

Pollution status of Legionella pneumophila in public places during summer in a city in central-south China,2023

目的了解2023年中南某市三类公共场所嗜肺军团菌污染状况,分析健康风险。方法于2023年7月采取非随机抽样方法在在中南某市三类公共场所采集集中空调水样、室内空气样本,以及公共设施物体表面样本进行检测和分析。采用培养法对集中空调冷却水和冷凝水嗜肺军团菌进行检测;采用荧光定量PCR对室内空气以及物体表面嗜肺军团菌进行检测。利用Fisher确切概率法用于评估水样类型、场所类型与健康风险等级的相关性。结果调查中共采集集中空调水样24份、室内空气样本213份以及公共设施物体表面样本282份。培养法检测结果显示,集中空调水样的总体阳性率为37.5%,其中冷却水的阳性率为55.6%(5/9),冷凝水的阳性率为26.7%(4/15)。其中,地铁站的集中空调水样阳性率为27.3%(3/11),宾馆的阳性率为66.7%(6/9),火车站水样中未检测出嗜肺军团菌(0/4)。风险分析发现,冷却水的高风险率为55.6%(5/9),冷凝水的高风险率为20.0%(3/15);地铁和宾馆水样的高风险率分别为27.3%(3/11)和55.6%(5/9)。荧光定量PCR结果显示,公共场所的室内空气和物体表面的检测结果均为阴性,中高风险率为0%。结论三类公共场所中,地铁和宾馆嗜肺军团菌阳性率较高,冷却水和冷凝水中均有较高检出率。

Objective To investigate the pollution of Legionella pneumophila in three types of public places in a city in Central-South China in 2023,and to analyze the health risks.Methods In July 2023,a targeted non-random sampling method was used to collect samples from centralized air conditioning water,indoor air,and surface of public facility objects in three types of public spaces in a city in Central-South China.Legionella pneumophila in the cooling water and condensate water of centralized air conditioning was determined using the culture method,while fluorescent quantitative PCR was applied for indoor air and object surface samples.The Fisher’s exact test was employed to evaluate the associations between water sample types,public space types,and health risk levels.Results In this study,24 samples from centralized air conditioning water systems,213 samples of indoor air,and 282 public facility object surface samples were collected.The culture assay showed that the overall positive rate was 37.5% for centralized air conditioning water samples,55.6%(5/9)for the cooling water samples,and 26.7%(4/15)for the condensate water samples.For centralized air conditioning water samples,the positive rate was 27.3%(3/11)in subway stations,66.7%(6/9)in hotels,and 0%(0/4)in train stations.In risk assessment,the high-risk rate was 55.6%(5/9)for cooling water,20.0%(3/15)for condensate water,27.3%(3/11)for subway water,and 55.6%(5/9)for hotel water.Fluorescence quantitative PCR showed that the positive rates of samples from indoor air and object surface in public places were 0%,and the medium and high risk rates were 0%.Conclusion In three types of public places,subways and hotels showed relatively high positive rates of Legionella pneumophila.Both cooling water and condensate water showed high positive rates.