公共场所水环境军团菌污染及其从业人员军团菌感染状况分析

目的分析公共场所水环境中军团菌污染及其从业人员军团菌感染状况方法以公共场所为研究对象,采集集中空调冷却塔水、淋浴水和自来水进行军团菌分离培养,同时对从业人员进行军团菌血清抗体和尿抗原检测。结果公共场所中空调冷却塔水、淋浴水和自来水军团菌阳性率分别为75%(111/148)、27%(27/100)和44%(22/50),以嗜肺军团菌污染为主,其中LP1为优势菌性,其他LP2-8、LP10、L.micdadei、L.bozemanii均有检出。公共场所从业人员军团菌血清抗体阳性率66.0%(369/559),抗LP1-14有检出,以抗LP12(45.9%)、抗LP4(43.4%)为优势血清型,抗LP1阳性率8.8%。公共场所从业人员LP1尿抗原阳性率0.0%(0/202)。结论公共场所冷却塔水、淋浴水和自来水军团菌尤其是嗜肺军团菌污染严重,从业人员普遍存在军团菌既往感染,公共场所存在发生社区获得性军团菌病暴发的安全隐患。     

北京市丰台区集中空调公共场所嗜肺军团菌污染状况及从业人员感染水平

目的了解北京市丰台区使用集中空调的公共场所嗜肺军团菌污染状况及从业人员嗜肺军团菌感染水平。方法于2012年7—9月采集北京市丰台区20家使用集中空调的公共场所环境样品进行嗜肺军团菌的巢氏PCR检测,于2012年12月—2013年1月对集中空调公共场所701名暴露人群和非集中空调场所440名对照人群进行血清嗜肺军团菌1~7IgG抗体检测。结果空气、景观水、室外景观土、室内花卉土及作为对照的土壤样品中均未检出嗜肺军团菌。冷却水、自来水、积尘、淋浴水中均检出嗜肺军团菌,阳性率分别为84.2%,10.9%,8.7%,3.6%。暴露组和对照组血清嗜肺军团菌1~7IgG抗体活力中位数分别为13、11U/ml,血清嗜肺军团菌抗体阳性率均为1.4%,差异均无统计学意义(P0.05)。结论本次调查的公共场所集中空调系统存在嗜肺军团菌污染,需采取防治措施。     

公共场所集中空调通风系统嗜肺军团菌污染对其从业人员嗜肺军团菌感染水平的Meta分析

目的系统评价我国公共场所集中空调通风系统嗜肺军团菌污染对其从业人员嗜肺军团菌感染水平的影响。方法检索Pub Med、中国期刊全文数据库、维普资讯网和万方数据库,收集2006—2014年发表的我国公共场所集中空调嗜肺军团菌污染对其从业人员嗜肺军团菌感染状况的研究文献,采用R 3.0.1软件进行综合分析,评价集中空调嗜肺军团菌污染对人群健康的影响。结果 16篇文献符合条件纳入研究,暴露组人群嗜肺军团菌抗体阳性率为16.01%(95%CI 9.18%~26.47%),对照组人群嗜肺军团菌抗体阳性率为9.60%(95%CI 5.10%~17.34%),暴露组抗体阳性率是对照组的1.68倍,差异有统计学意义(P0.05)。分层分析结果发现不同性别和不同年龄的从业人员嗜肺军团菌抗体水平差异无统计学意义(P0.05),不同类别场所间从业人员嗜肺军团菌抗体水平差异有统计学意义(P0.05),其中超市工作人员的嗜肺军团菌抗体阳性率最高。结论对我国公共场所集中空调嗜肺军团菌的控制和监督监测管理仍需加强。     

2018—2019年北京市朝阳区公共场所水环境中嗜肺军团菌污染状况及健康风险分析

目的了解北京市朝阳区公共场所水环境中嗜肺军团菌的污染状况和健康风险。方法于2018—2019年在北京市朝阳区部分公共场所中,采集淋浴水、集中空调系统冷却水和冷凝水,检测嗜肺军团菌,分型并计算含菌浓度,根据含菌浓度评价其健康风险。结果在112户公共场所中采集水环境样品共651份,嗜肺军团菌阳性率18.6%(121/651),血清1型41份,血清2-14型80份。不同水环境中嗜肺军团菌阳性率的差异有统计学意义(χ^(2)=21.89,P<0.05),淋浴水和冷却水的阳性率高于冷凝水的阳性率。不同场所淋浴水中嗜肺军团菌的阳性率差异无统计学意义(χ^(2)=4.03,P>0.05),冷却水中嗜肺军团菌的阳性率差异无统计学意义(χ^(2)=0.12,P>0.05)。含致病力较强的1型嗜肺军团菌的中高风险样品均为冷却水。结论朝阳区公共场所水环境中存在嗜肺军团菌污染的情况,淋浴水和集中空调冷却水中有较高的检出率,冷却水中嗜肺军团菌的污染带来的健康风险较高。     

江苏省某城市公共场所人群军团菌感染现况研究

目的：了解江苏省某城市公共场所人群军团菌感染现况,为国家公共场所空气传播疾病监控技术的研究提供基础资料。方法：抽取暴露组和对照组各200人,采用问卷调查,同时采集人群血清进行军团菌抗体检测。结果：某城市公共场所工作人群军团菌抗体总阳性率为57.42%,其中,暴露组军团菌抗体阳性率为62.38%,对照组为51.23%,两组相比,差异显著（P〈0.05）。血清分型从LP1~LP14型均有检出,其中以LP12阳性率最高,为42.31%;其次为LP4、LP5和LP14,阳性率分别为36.54%、14.01%和13.74%。军团菌抗体阳性率在性别、年龄和工作类别间无显著性差异（P〉0.05）。结论：调查人群中普遍存在不同程度的LP1~LP14的感染,感染血清型以LP12、LP4占优势,空调系统冷却塔水中军团菌污染水平可以直接影响人群的血清抗体水平,使用集中空调是人群军团菌抗体阳性率增高的危险因素。     

大连市集中空调场所军团菌污染及人群健康状况影响调查

目的调查大连市集中空调场所冷却塔水军团菌污染状况及暴露人群中军团菌隐性感染状况,研究军团菌对人群健康的影响因素。方法2005年8～9月,随机采集大连市使用集中空调的32所公共场所集中空调冷却塔水,采用分离病原培养法进行军团菌检测;随机抽取使用集中空调场所的工作人员血样,采用微量凝集试验法,进行血清军团菌抗体检测。结果大连市公共场所集中空调冷却塔水军团菌检测的场所阳性率为53.13%,军团菌血清型分别为嗜肺军团菌(Legionella pneumophila,Lp)Lp7、Lp8、Lp9和Lp10型。其中,Lp9型28株,占总菌株的77.78%,为优势菌株。人群血清学抗体检测显示,使用集中空调的公共场所人群Lp10感染率较高。结论大连市使用集中空调的场所存在军团菌污染,人群中存在军团菌隐性感染。     

公共场所从业人员和综合医院肺炎患者嗜肺军团菌尿抗原和血清抗体检测

目的调查公共场所从业人员和综合医院肺炎患者嗜肺军团菌尿抗原和血清抗体的阳性情况。方法于2012—2014年选择华东两城市集中空调系统嗜肺军团菌培养法阳性的7家公共场所从业人员(n=280)和华北、华东和华南共4城市的7家综合医院肺炎患者(尿样:n=262;血样:n=269)为研究对象,采集人群的尿和血清样本,以酶联免疫吸附法检测尿中嗜肺军团菌抗原和血清嗜肺军团菌抗体。结果从业人员嗜肺军团菌尿抗原和血清抗体阳性率为10.4%和36.1%,肺炎患者嗜肺军团菌尿抗原和血清抗体阳性率为11.8%和18.2%。从业人员嗜肺军团菌尿抗原和血清抗体阳性检出率差异有统计学意义(χ~2=7.133,P=0.000),肺炎患者嗜肺军团菌尿抗原和血清抗体阳性检出率差异无统计学意义(χ~2=0.291,P=0.794)。结论本次调查的公共场所从业人员和综合医院肺炎患者均存在嗜肺军团菌感染。     

公共场所人群嗜肺军团菌血清抗体水平的调查研究

目的:了解温州市部分人群血清嗜肺军团菌的抗体阳性率以及嗜肺军团菌抗体(LP1～10)的分布特点。方法:采用微量凝集试验(MAT)测定就业人员血清中嗜肺军团菌1至10型抗体滴度。结果:1000例人群血清抗嗜肺军团菌抗体阳性89例,总阳性率为8.9%,其中暴露人群血清中嗜肺军团菌感染的阳性率11.6%(58/500),对照人群血清中嗜肺军团菌感染的阳性率6.2%(31/500),阳性率有显著性差异,暴露人群高于对照人群(χ2=8.991,P<0.05)。在阳性结果中,2种及以上血清型同时阳性为17份,占19.10%(17/89)。结论:我市健康人群普遍存在不同程度和不同血清型的嗜肺军团菌隐性感染,使用中央空调的场所是嗜肺军团菌感染的高危场所,应加强监测。     

公共场所不同环境介质军团菌污染状况及从业人员感染状况分析

目的研究公共场所不同环境介质军团菌污染状况及从业人员军团菌感染状况。方法以商场、酒店为调查对象,采集不同类型环境样品进行军团菌检测,同时对调查单位从业人员进行军团菌血清抗体和尿抗原检测。结果公共场所集中空调系统(送风口空气、风管积尘和冷却塔水)、水系统(景观水、淋浴水和自来水)、花卉土中均检出军团菌,三者阳性率无统计学差异(P0.05)。公共场所从业人员军团菌血清抗体阳性率10.6%(17/160),尿抗原阳性率3.8%(6/160)。结论公共场所多种环境介质均受到军团菌污染,从业人员存在军团菌感染,需对公共场所多种环境介质均进行军团菌污染防治管理。     

大型公共场所空调冷却水军团菌污染及人群感染水平的研究

目的：了解绍兴市公共场所集中空调冷却水军团菌污染现况及相关人群感染水平。方法：根据《公共场所集中空调通风系统卫生规范》，随机抽取绍兴市42家大型酒店、宾馆、商场、超市、医院、证券公司、写字楼等公共场所的59只大型空调冷却塔共236份冷却塔水；抽取相应公共场所健康工作人员520人（暴露人群）和非从事公共场所行业的健康人群（对照人群）511人，分别进行军团菌及人群血清学检测。结果：所调查的大型公共场所空调冷却塔水中军团菌检出率为72．88％，共分离43株军团菌，均为嗜肺军团菌种，其中28株菌的菌型LP1。暴露人群血清中军团菌感染的阳性率14．87％；对照人群4．81％，阳性率差异有非常显著性，暴露人群高于对照人群（χ^2=23．29，P〈0．01）。结论：军团菌广泛存生于公共场所空调冷却塔，已对暴露人群的健康造成潜在威胁，对这一潜在传染来源应采取有效防范措施。     

Cooling Towers contribute to the high seroprevalence of Legionella pneumophila antibody among hotel workers

Objectives

Regular disinfection work of the cooling towers (CTs) were carried out according to schedule, nevertheless 89.6% of the CTs were still found to be colonized by Legionella pneumophila in our survey in Changzhou city, China. The aim of the study was to observe the effect of L. pneumophila on workers exposed to contaminated cooling towers (CT).

Methods

A total of 364 subjects were randomly selected for the serum testing and the questionnaire survey. They were either from the hotel with contaminated CTs or without CTs (used as control). heir serum anti-L. pneumophila antibodies were tested using commercial IFA kits.

Results

The results showed that the prevalence of anti-L. pneumophila group 1 antibodies in the exposed population was significantly higher than control subjects (OR?=?2.845, P?=?0.019). The possible confounding factors were analyzed. Questionnaires results analysis found that the frequency of flu-like symptoms in the exposed group was also significantly higher; and the indoor air quality was related to the serum anti-L. pneumophila group 1.

Conclusions

The L. pneumophila contaminated CTs contribute to the high seroprevalence of anti-L. pneumophila antibodies; tap water and shower water are also possible contamination resources.     

Cytopathogenicity and molecular subtyping of Legionella pneumophila environmental isolates from 17 hospitals

The cytopathogenicity of 22 Legionella pneumophila isolates from 17 hospitals was determined by assessing the dose of bacteria necessary to produce 50% cytopathic effect (CPED50) in U937 human-derived macrophages. All isolates were able to infect and grow in macrophage-like cells (range log10 CPED50: 2.67-6.73 c.f.u./ml). Five groups were established and related to the serogroup, the number of PFGE patterns coexisting in the same hospital water distribution system, and the possible reporting of hospital-acquired Legionnaires' disease cases. L. pneumophila serogroup 1 isolates had the highest cytopathogenicity (P=0.003). Moreover, a trend to more cytopathogenic groups (groups 1-3) in hospitals with more than one PFGE pattern of L. pneumophila in the water distribution system (60% vs. 17%) and in hospitals reporting cases of hospital-acquired Legionnaires' disease (36.3% vs. 16.6%) was observed. We conclude that the cytopathogenicty of environmental L. pneumophila should be taken into account in evaluating the risk of a contaminated water reservoir in a hospital and hospital acquisition of Legionnaires' disease.     

A hospital outbreak of Legionella from a contaminated water supply

The authors performed a cross-sectional epidemiological survey to investigate the source of a hospital Legionella outbreak originating in contaminated water. Water temperature and air humidity were measured around possible contamination sources. A dead-end pipe was found to contain Legionella pneumophila serogroup 1. All individuals who acquired legionellosis had spent at least 30 min within 2 m of the contamination source. Among staff, 41 of 71 were exposed, and 31 of these fell ill. All 7 patients exposed to the contaminated water acquired legionellosis. None of the 94 bed-ridden patients from the same units developed the disease. An aerosol with 60% relative air humidity was formed near the suspect water faucets, but the humidity fell rapidly farther from the water source, suggesting that desiccation decreased the risk of infection. The healthy personnel and patients closest to the source acquired legionellosis, suggesting that risk was related less to compromised patients than to exposure.     

Legionellosis from Legionella pneumophila serogroup 13

We describe 4 cases of Legionella pneumophila serogroup 13-associated pneumonia. These cases originate from a broad geographic range that includes Scotland, Australia, and New Zealand. L. pneumophila serogroup 13 pneumonia has a clinically diverse spectrum that ranges from relatively mild, community-acquired pneumonia to potentially fatal severe pneumonia with multisystem organ failure. All cases were confirmed by culture and direct fluorescent antibody staining or indirect immunofluorescent antibody tests. Proven or putative sources of L. pneumophila serogroup 13 infections in 2 patients included a contaminated whirlpool spa filter and river water. An environmental source was not found in the remaining 2 cases; environmental cultures yielded only other L. pneumophila serogroups or nonpneumophila Legionella species. We describe the clinical and laboratory features of L. pneumophila serogroup 13 infections. L. pneumophila serogroup 13 pneumonia is rarely reported, but it may be an underrecognized pathogenic serogroup of L. pneumophila.     

Nosocomial legionellosis associated with use of oxygen bubble humidifiers and underwater chest drains

In 1 year 12 of 48 patients who developed fatal pneumonia following admission with non-respiratory disorders to the Hospital Molinette, Torino, yielded Legionella pneumophila serogroup 1 from lung at autopsy. Patients were hospitalized on seven different wards for different conditions; only two of the wards had air conditioning but legionellas were not isolated from these. All patients were in poor health or immunocompromised. Some patients had inhaled humidified oxygen from piped supplies and three had undergone surgery. Legionella pneumophila serogroup 1 was detected in the water of oxygen bubble humidifiers and an underwater chest drain. The contaminated devices had been filled with tap or distilled water and the hospital water supply was found to be contaminated with L. pneumophila serogroup 1. Our findings suggest that filling bubble humidifiers or underwater chest drains with tap water is a potential hazard and should be avoided.     

Isolation of Legionella pneumophila from the UOEH cooling tower

Twelve samples of water taken from the cooling tower of UOEH were examined for the presence of microorganisms belonging to the genus Legionella by using a new selective medium, Wadowsky-Yee-Okuda (WYO) medium. Three samples contained this organism and they were identified as Legionella pneumophila from their biochemical properties. Among the three contaminated samples, two yielded L. pneumophila serogroup 1 and 3, and the other contained only L. pneumophila serogroup 1. One of the samples of the contaminated cooling tower water was treated with sodium hypochlorite as a disinfectant, indicating that this agent is probably not effective in eliminating L. pneumophila from cooling tower water at that concentration. An effective method of disinfection for Legionella spp. in the cooling tower must be developed to prevent infection in the hospital.     

嗜肺性军团杆菌培养基(BALM)的研究

蓝藻培养液能促进嗜肺性军团杆菌的生长,将此培养滤液适量加入参照硝酸铁培养基配方用国产试剂自制的基础培养基(LM)中,制成蓝藻培养基(BALM)。嗜肺性军团杆菌第6血清型标准株在BALM上形成菌落的能力优于BCYE;第1血清型标准株在两种培养基上的菌落形成能力较接近。从临床标本中分离NANJ-1株的结果表明,该菌株在BALM上的生长时间、菌落大小优于BCYE和其他几种培养基。     

Clinical and environmental distribution of Legionella pneumophila in a university hospital in Italy: efficacy of ultraviolet disinfection

The molecular epidemiology of Legionella pneumophila in the 'V. Monaldi' University Hospital was studied. Seven cases of nosocomial Legionnaires' disease were diagnosed between 1999 and 2003. Two clinical legionella strains obtained from two patients in the adult cardiac surgery unit (CSU) and 30 environmental legionella strains from the paediatric and adult CSUs, neonatal intensive care unit (NICU) and the cardiorespiratory intensive care unit (CR-ICU) were serotyped and genotyped. L. pneumophila serogroup 1/Philadelphia with an identical pulsed-field gel electrophoresis (PFGE) profile A was isolated from two patients in the adult CSU, and from three and one water samples taken in the adult CSU and the paediatric CSU, respectively, from 2001 to 2002. Furthermore, L. pneumophila serogroup 3 with an identical PFGE profile B was identified in 20 environmental strains from all wards, L. pneumophila serogroup 3 with PFGE profile C was identified in a single environmental strain from the CR-ICU, and non-pneumophila Legionella with identical PFGE profile D was identified in five environmental strains from the adult CSU, paediatric CSU and NICU. Ultraviolet irradiation was effective in disinfection of the hospital water supplies in the adult and paediatric CSUs contaminated by L. pneumophila clone associated with nosocomial Legionnaires' disease. In conclusion, these data demonstrate that two cases of nosocomial legionellosis were caused by the persistence of a single clone of L. pneumophila serogroup 1/Philadelphia in the hospital environment, and that disinfection by ultraviolet irradiation may represent an effective measure to prevent nosocomial Legionnaires' disease.     

A community hospital outbreak of legionellosis. Transmission by potable hot water

Seven cases of nosocomial legionellosis occurred between February and September 1982 in a small community hospital in Upstate New York. All seven were cases of Legionella pneumophila serogroup 1; six were hospital patients and one a hospital employee. None of the cases died. During the peak of the outbreak, the incidence of nosocomial legionellosis was 1.2 cases per 100 patient discharges. An epidemiologic comparison of the six patient cases with 21 matched patient controls suggested that longer hospital stay (chi 1(2) = 24.2, p less than 0.001) and the proximity of patients' rooms to ward showers (chi 1(2) = 4.4, p less than 0.04) were significant risk factors for acquiring legionellosis. An environmental investigation demonstrated that the ward showers and the hospital hot water system were contaminated with L. pneumophila serogroup 1. Monoclonal antibody subtyping performed on isolates obtained during the outbreak investigation confirmed that the hot water system and patient isolates had an identical pattern of reactivity. The outbreak demonstrates that legionellosis can be a significant cause of nosocomial pneumonia in a community hospital and that transmission can occur from contaminated potable hot water sources, potentially via shower aerosols.     

Nosocomial legionella pneumonia: demonstration of potable water as the source of infection

From January 1983 until December 1985, 35 cases of sporadic nosocomial legionella pneumonia, all caused by Legionella pneumophila, were diagnosed in a university hospital. L. pneumophila serogroup (SG) 1 was cultured from 12 of the 35 cases and compared to corresponding L. pneumophila SG 1 isolates from water outlets in the patients' immediate environment by subtyping with monoclonal antibodies. The corresponding environmental isolates were identical to 9 out of 12 (75%) of those from the cases. However, even in the remaining three cases identical subtypes were found distributed throughout the hospital water supply. From the hospital water supply four different subtypes of L. pneumophila SG 1 were isolated, three of which were implicated in legionella pneumonia. Of 453 water samples taken during the study 298 (65.8%) were positive for legionellae. Species of Legionella other than L. pneumophila have not been isolated. This may explain the exclusiveness of L. pneumophila as the legionella pneumonia-causing agent. Our results suggest that the water supply system was the source of infection.