首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 604 毫秒
1.
2.
A preliminary survey of water systems in hospitals and hotels showed that Legionella pneumophila may be found in water storage and distribution systems as well as in the recirculating cooling water of air-conditioning plants. Altogether 42 isolates of L pneumophila were made from 31 establishments, six of which were associated with cases of legionnaires'' disease but in 25 of which there was no known association with disease. In the six establishments implicated epidemiologically as the source of legionnaires'' disease, these organisms were found in each of their water-distribution systems and also in the cooling water from each of the three with cooling towers. In establishments not associated with cases, water from three out of nine cooling towers, four out of 24 taps or showers, and one out of 15 storage tanks was found to contain legionellae. The organisms were isolated by guinea-pig inoculation and subsequent culture of their peritoneal fluid, liver, and spleen. Finding L pneumophila in water systems in the absence of cases of legionnaires'' disease should not at present be an indication for attempts at eradication.  相似文献   

3.
Genotypic variability and clonal persistence are important concepts in molecular epidemiology as they facilitate the search for the source of sporadic cases or outbreaks of legionellosis. We studied the genotypic variability and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns over time (period > 6 months) in 34 positive cooling towers from two different areas. In area A, radius of 70 km, 52 indistinguishable PFGE patterns were differentiated among the 27 cooling towers. In 13 cooling towers we observed ≥ 2 PFGE patterns. Each cooling tower had its own indistinguishable Legionella PFGE pattern which was not shared with any other cooling tower. In area B, radius of 1 km, 10 indistinguishable PFGE patterns were obtained from the seven cooling towers. In four, we observed ≥ 2 PFGE patterns. Three of these 10 indistinguishable PFGE patterns were shared by more than one cooling tower. In 27 of 34 cooling towers the same PFGE pattern was recovered after 6 months to up to 5 years of follow-up. The large genotypic diversity of Legionella observed in the cooling towers aids in the investigation of community outbreaks of Legionnaires' disease. However, shared patterns in small areas may confound the epidemiological investigation. The persistence of some PFGE patterns in cooling towers makes the recovery of the Legionella isolate causing the outbreak possible over time.  相似文献   

4.
This study was designed to investigate the possible association of high colony counts of legionellae from cooling towers and evaporative condensers with Legionnaires' disease outbreaks. We obtained legionellae counts from samples of cooling towers and evaporative condensers that were the likely sources of two different Legionnaires' disease outbreaks and compared these counts with those from cooling towers that were not associated with reports of human disease. Among 675 potential control cooling tower that were samples from 258 facilities, 136 facilities had one or more cooling towers that met our criteria for inclusion into the study. Samples taken from buildings where an outbreak had occurred had much higherLegionella counts than did samples from other buildings. Colony counts from the two outbreak-associated facilities were significantly higher than colony counts from other facilities [Wilcoxon Rank Sum Test (Exact), p<0.01]. The results of the study suggest that, among cooling towers that test positive for the presence of legionellae, higher colony counts are associated with higher risk of Legionnaires' disease.  相似文献   

5.
During the summer of 2012, a major Legionella pneumophila serogroup 1 outbreak occurred in Quebec City, Canada, which caused 182 declared cases of Legionnaire''s disease and included 13 fatalities. Legionella pneumophila serogroup 1 isolates from 23 patients as well as from 32 cooling towers located in the vicinity of the outbreak were recovered for analysis. In addition, 6 isolates from the 1996 Quebec City outbreak and 4 isolates from patients unrelated to both outbreaks were added to allow comparison. We characterized the isolates using pulsed-field gel electrophoresis, sequence-based typing, and whole genome sequencing. The comparison of patients-isolated strains to cooling tower isolates allowed the identification of the tower that was the source of the outbreak. Legionella pneumophila strain Quebec 2012 was identified as a ST-62 by sequence-based typing methodology. Two new Legionellaceae plasmids were found only in the epidemic strain. The LVH type IV secretion system was found in the 2012 outbreak isolates but not in the ones from the 1996 outbreak and only in half of the contemporary human isolates. The epidemic strains replicated more efficiently and were more cytotoxic to human macrophages than the environmental strains tested. At least four Icm/Dot effectors in the epidemic strains were absent in the environmental strains suggesting that some effectors could impact the intracellular replication in human macrophages. Sequence-based typing and pulsed-field gel electrophoresis combined with whole genome sequencing allowed the identification and the analysis of the causative strain including its likely environmental source.  相似文献   

6.
Legionella pneumophila serogroup 1 causes Legionnaires'' disease. Water systems contaminated with Legionella are the implicated sources of Legionnaires'' disease. This study analyzed L. pneumophila serogroup 1 strains in China using sequence-based typing. Strains were isolated from cooling towers (n = 96), hot springs (n = 42), and potable water systems (n = 26). Isolates from cooling towers, hot springs, and potable water systems were divided into 25 sequence types (STs; index of discrimination [IOD], 0.711), 19 STs (IOD, 0.934), and 3 STs (IOD, 0.151), respectively. The genetic variation among the potable water isolates was lower than that among cooling tower and hot spring isolates. ST1 was the predominant type, accounting for 49.4% of analyzed strains (n = 81), followed by ST154. With the exception of two strains, all potable water isolates (92.3%) belonged to ST1. In contrast, 53.1% (51/96) and only 14.3% (6/42) of cooling tower and hot spring, respectively, isolates belonged to ST1. There were differences in the distributions of clone groups among the water sources. The comparisons among L. pneumophila strains isolated in China, Japan, and South Korea revealed that similar clones (ST1 complex and ST154 complex) exist in these countries. In conclusion, in China, STs had several unique allelic profiles, and ST1 was the most prevalent sequence type of environmental L. pneumophila serogroup 1 isolates, similar to its prevalence in Japan and South Korea.  相似文献   

7.
目的:研究早期康复护理对肠内营养治疗的高血压颅内出血患者预后的影响。方法:选取2010 年1 月~2012 年10 月间入 院诊治的高血压颅内出血并应用肠内营养支持治疗的患者120 例,随机分为实验组(60 例)和对照组(60 例)。对照组应用常规护 理办法,实验组在其基础上应用早期康复护理,随访1 年后观察两组患者预后的生活质量情况、GCS(格拉斯哥昏迷指数)评分以 及并发症的发生情况。结果:随访1 年后,实验组的生活质量显著高于对照组(P<0.05);护理干预前两组患者的GCS 评分无差异, 护理干预后实验组的GCS 评分显著高于对照组(P<0.05);实验组在肺部感染、下肢静脉血栓、肩手综合征等并发症的发生例数均 显著低于对照组(P<0.05)。结论:针对肠内营养支持治疗的高血压颅内出血患者应用早期康复护理可有效改善患者的昏迷程度、 预防并发症,有助于提高患者的生活质量。  相似文献   

8.
To complement the role of primary care teams working with patients with HIV disease and AIDS within greater London and to ease the load on the special hospital units a home support team was developed. It comprises six specialist nurses, a general practitioner trained medical officer, and a receptionist and is funded from regional and district sources and charities. A nurse is available for out of hours and emergency weekend calls, with support from the patient''s general practitioner or the attached medical officer. During the first 18 months 249 patients were seen; the mean duration of care was five months. Nearly a third (18/50, 30%) of patients who were terminally ill died at home. The team''s activities included practical nursing care, emotional support for carers and patients, and advice and guidance to primary care teams. Problems in providing care in patients'' homes included issues relating to confidentiality and 24 hour cover. With the increasing incidence of HIV infection the home support team may be a useful model for care of large numbers of patients with symptomatic HIV disease, especially in large urban areas.  相似文献   

9.
OBJECTIVE--To investigate the source of infections associated with orthopaedic prostheses. DESIGN--Analysis of four infections of prosthetic joints with case records; minimum inhibitory and minimum bactericidal concentrations and sodium dodecylsulphate polyacrylamide gel electrophoresis of the cell wall polypeptides of the Streptococcus sanguis isolates from the mouth and infected prostheses; examination of the patients'' mouths for periodontal disease and caries. SUBJECTS--Four adults (three men) aged 58-83. RESULTS--For each patient the strain of S sanguis isolated from the mouth was indistinguishable from that isolated from the prosthesis. All patients had severe periodontal disease and caries. CONCLUSIONS--The mouth was probably the source of bacterial infection in the prosthetic joints of these patients; the route of infection was possibly haematogenous. Incipient oral infection should be treated before joint replacement, and oral health should be maintained indefinitely.  相似文献   

10.
Every year an estimated 4–5 million migratory birds collide with communication towers in the United States. We examined the relative risks that tower support systems and tower height pose to migrating and other birds. We collected data comparing tower support systems (guyed vs. unguyed) and tower height categories in Michigan during 20 days of the peak of songbird migration at 6 towers in September–October 2003, 23 towers in May 2004, 24 towers in September 2004, and 6 towers in both May and September 2005. We systematically and simultaneously searched for bird carcasses under each tower and measured carcass removal and observer detection rates each season. Of those towers, 21 were between 116 and 146 m above ground level (AGL, medium) and 3 were >305 m AGL (tall). During the five 20-day sample periods we found a mean of 8.2 bird carcasses per guyed medium tower and a mean of 0.5 bird carcasses under unguyed medium towers. During four 20-day sample periods we detected a mean of 34.7 birds per guyed tall tower. Using both parametric and nonparametric tests (Mann–Whitney U-test, Kruskal–Wallis test, and Tukey's Honestly Significant Difference multiple comparison procedure) we determined that unguyed medium towers were involved in significantly fewer fatalities than guyed medium towers. We detected 54–86% fewer fatalities at guyed medium towers than at guyed tall towers. We found 16 times more fatalities at guyed medium towers than at unguyed medium towers. Tall, guyed towers were responsible for 70 times as many bird fatalities as the unguyed medium towers and nearly five times as many as guyed medium towers. These findings will provide managers and regulators, such as the US Fish and Wildlife Service, with quantitative data; thereby, allowing them to effectively work with the Federal Communications Commission in siting and authorizing tower placement. © 2011 The Wildlife Society.  相似文献   

11.
The effects of biocidal treatments for cooling towers were examined through the use of chemicals and ultraviolet irradiation to inhibit the growth of legionellae and other microorganisms. In the water of cooling towers without continuous biocidal treatments, heterotrophic bacteria and bacterivorous protozoan first appeared, and then legionellae increased up to 10(4) CFU/100 ml. When a UV sterilizer was connected to the cooling tower, the legionellae count was 1/10 or 1/100 of that in the nontreated tower water. In the water of towers supplemented continuously with the biocidal chemicals, legionellae were not found during a 4-month period. The biocidal treatments tested were proved to suppress the increase of legionellae in cooling-tower water, and thus are useful in preventing the outbreak of legionellosis due to inhalation of contaminated aerosol from the cooling tower system.  相似文献   

12.
Summary From the time of the report of the Philadelphia outbreak in 1976, the airborne contamination of patients through cooling towers had been suspected although never truly corroborated. Since then, contamination through different air conditioning systems or cooling towers has often been implicated in both epidemics and endemics as well as in sporadic cases. Whatever the conditions, contaminated water present in the different air conditioning systems remains the main source of infection. From the contaminated sites an aerosol occurs. The infectivity of the aerosol is linked to the size of the droplets (d≥μm). A close surveillance is mandatory and preventive measures have to be tanken.  相似文献   

13.
The organisation of care for patients with head injuries in Scotland was investigated by studying retrospectively 785 patients admitted in 1974 and 1975 to neurosurgical units in Glasgow, Aberdeen, and Dundee. The reasons for the injuries and the patients'' clinical conditions were similar in each unit. The referral practices at the hospitals containing the units were compared and found to be different from that of the unit in Edinburgh. It is concluded that patients in the Glasgow, Aberdeen, and Dundee units, which operate a similar policy for head-injured patients, are in general similar. Transferring to a neurosurgical unit only selected patients rather than all patients with head injuries is safe practice only if policies are agreed with primary surgeons and patients can be transferred without delay.  相似文献   

14.
We refer to Oswaldo Cruz''s reports dating from 1913 about the necessities of a healthcare system for the Brazilian Amazon Region and about the journey of Carlos Chagas to 27 locations in this region and the measures that would need to be adopted. We discuss the risks of endemicity of Chagas disease in the Amazon Region. We recommend that epidemiological surveillance of Chagas disease in the Brazilian Amazon Region and Pan-Amazon region should be implemented through continuous monitoring of the human population that lives in the area, their housing, the environment and the presence of triatomines. The monitoring should be performed with periodic seroepidemiological surveys, semi-annual visits to homes by health agents and the training of malaria microscopists and healthcare technicians to identify Trypanosoma cruzi from patients'' samples and T. cruzi infection rates among the triatomines caught. We recommend health promotion and control of Chagas disease through public health policies, especially through sanitary education regarding the risk factors for Chagas disease. Finally, we propose a healthcare system through base hospitals, intermediate-level units in the areas of the Brazilian Amazon Region and air transportation, considering the distances to be covered for medical care.  相似文献   

15.
目的:探讨不同剂量沐舒坦对老年中重度慢性阻塞性肺疾病急性加重期(AECOPD)患者肺功能的影响。方法:将200例诊断为老年中重度AECOPD的患者采用随机数字表法分为4组,分别给予沐舒坦每次30mg、90mg、330mg、溴己新4mg静脉滴注,3次/d,观察第一天,第四天,第七天肺功能的变化。结果:330 mg组在老年AECOPD治疗中对肺功能的改善程度明显优于其他三组,差异均有显著性,330 mg组第四天与第七天,无明显差异。而30 mg组和90 mg与溴己新组该三组用药前与治疗后第四天比较无明显差异,用药后第七天优于用药前和用药后第四天,差异有显著性。结论:大剂量沐舒坦治疗老年中重度AECOPD,安全性高,能明显快速改善患者肺功能,缩短住院时间,减轻患者经济负担。  相似文献   

16.
17.
Adaptation of amoebae to four cooling tower Biocides, which included a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds (TBT/QAC), another QAC alone, and an isothiazolin derivative, was studied. Previously we found that amoebae isolated from waters of cooling towers were more resistant to cooling tower biocides than amoebae from other habitats. Acanthamoeba hatchetti and Cochliopodium bilimbosum, obtained from American Type Culture Collection and used in the previous studies, were tested to determine whether they could adapt to cooling tower Biocides. A. hatchetti was preexposed to subinhibitory concentrations of the four Biocides for 72h, after which they were tested for their resistance to the same and other biocides. C. bilimbosum was exposed to only two biocides, as exposure to the other two was lethal after 72 h. Preexposure to the subinhibitory concentrations of the Biocides increased the resistance of the amoebae, as indicated by a significant increase in the minimum inhibitory concentration (up to 30-fold). In addition, cross-resistance was also observed, i.e., exposure to one biocide caused resistance to other biocides. These results show that amoebae can adapt to biocides in a short time. The phenomenon of cross-resistance indicates that regularly alternating biocides, as is done to control microbial growth in cooling towers, may not be effective in keeping amoeba populations in check. On the contrary, exposure to one biocide may boost the amoebae's resistance to a second biocide before the second biocide is used in the cooling tower. Since amoebae may harbor Legionella, or alone cause human diseases, these results may be important in designing effective strategies for controlling pathogens in cooling towers. Correspondence to: S.G. Berk.  相似文献   

18.
The presence of microbial cells on surfaces results in the formation of biofilms, which may also give rise to microbiologically influenced corrosion. Biofilms accumulate on all submerged industrial and environmental surfaces. The efficacy of disinfectants is usually evaluated using planktonic cultures, which often leads to an underestimate of the concentration required to control a biofilm. The aim of this study was to investigate the efficacy of monochloramine on biofilms developed in a cooling tower. The disinfectants selected for the study were commercial formulations recommended for controlling microbial growth in cooling towers. A cooling tower and a laboratory model recirculating water system were used as biofilm reactors. Although previous studies have evaluated the efficacy of free chlorine and monochloramine for controlling biofilm growth, there is a lack of published data concerning the use monochloramine in cooling towers. Stainless steel coupons were inserted in each tower basin for a period of 30 d before removal. Monochloramine and free chlorine were tested under identical conditions on mixed biofilms which had been allowed to grow on coupons. Monochloramine was found to be significantly more effective than free chlorine against cooling tower biofilms.  相似文献   

19.
The presence of microbial cells on surfaces results in the formation of biofilms, which may also give rise to microbiologically influenced corrosion. Biofilms accumulate on all submerged industrial and environmental surfaces. The efficacy of disinfectants is usually evaluated using planktonic cultures, which often leads to an underestimate of the concentration required to control a biofilm. The aim of this study was to investigate the efficacy of monochloramine on biofilms developed in a cooling tower. The disinfectants selected for the study were commercial formulations recommended for controlling microbial growth in cooling towers. A cooling tower and a laboratory model recirculating water system were used as biofilm reactors. Although previous studies have evaluated the efficacy of free chlorine and monochloramine for controlling biofilm growth, there is a lack of published data concerning the use monochloramine in cooling towers. Stainless steel coupons were inserted in each tower basin for a period of 30 d before removal. Monochloramine and free chlorine were tested under identical conditions on mixed biofilms which had been allowed to grow on coupons. Monochloramine was found to be significantly more effective than free chlorine against cooling tower biofilms.  相似文献   

20.

Purpose

To provide prognosis of an 18 patient cohort who were confirmed to have H7N9 lung infection in Shanghai.

Methods

Patients'' history, clinical manifestation, laboratory test, treatment strategy and mortality were followed and recorded for data analysis.

Results

A total of 18 patients had been admitted into Shanghai Public Health Clinical Center from April 8th to July 29, 2013. 22.2% of the patients were found to have live poultry contact history and 80% were aged male patients with multiple co-morbidities including diabetes, hypertension and/or chronic obstructive pulmonary disease (COPD). This group of patients was admitted to the clinical center around 10 days after disease onset. According to laboratory examinations, increased C reactive protein (CRP), Procalcitonin (PCT), Plasma thromboplastin antecedent (PTA) and virus positive time (days) were indicative of patients'' mortality. After multivariate analysis, only CRP level showed significant prediction of mortality (P = 0.013) while results of prothrombin time (PT) analysis almost reached statistical significance (P = 0.056).

Conclusions

H7N9 infection induced pneumonia of different severity ranging from mild to severe pneumonia or acute lung injury/acute respiratory distress syndrome to multiple organ failure. Certain laboratory parameters such as plasma CRP, PCT, PTA and virus positive days predicted mortality of H7N9 infection and plasma CRP is an independent predictor of mortality in these patients.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号