Microbial contamination of dialysate and its prevention in haemodialysis units

At the haemodialysis centres of nine hospitals in Japan, microbial contamination of treated water (reverse osmosis method), acid and bicarbonate concentrates, and dialysate was investigated. Among these fluids used in haemodialysis, the dialysate was most frequently contaminated and had the highest concentration of bacteria. Of 40 dialysate samples analysed, 42.5% showed a bacterial count of more than 2000cfu/mL, which was above the Association for the Advancement of Medical Instrumentation (AAMI) standard. However, among the 40 samples from 20 dialysis machines, all six dialysate samples from three dialysis machines that used an ultrafiltration membrane in the circuit before the entrance of the dialysate into the dialyser, showed a bacterial count of < or =10 cfu/mL. In addition, when an ultrafiltration membrane was used in the circuit before the entrance of the dialysate into the dialyser for four dialysis machines showing dialysate samples contaminated with 10(4)-10(5)cfu/mL the bacterial count in dialysate samples from these machines became zero. Because dialysis machines are susceptible to microbial contamination, it is necessary to take measures such as placing an ultrafiltration membrane into the circuit before the entrance of dialysate into the dialyser.     

Recovery of high-level streptomycin-resistant enterococci from hemodialysis water and dialysate in 85 Greek renal units.

In the 85 renal units of Greece, enterococci were recovered from 10 samples of tap water, 6 of treated hemodialysis water, and 21 of dialysate. Eleven isolates were Enterococcus faecium, and 8 were Enterococcus raffinosus; 6 other additional enterococcal species were found. Twenty-two strains exhibited high-level resistance to streptomycin, 16 were resistant to rifampicin, and one to erythromycin. In our hemodialysis units, treated water and dialysate raise concern regarding transfer to patients of uncommon enterococcal species exhibiting high-level streptomycin resistance.     

重庆市8家三级医院血液透析用水和透析液细菌学横断面调查

目的了解重庆市医院透析室透析用水、透析液的内毒素及细菌污染情况。方法采集该市8家三级甲等医院透析用水及透析液标本,进行细菌培养和菌落计数;用ATi动态试管仪测定反渗水及透析液中内毒素含量。结果 8家医院透析用水细菌培养计数均≤200 CFU/mL,1家医院透析液细菌计数2 000 CFU/mL,培养出的细菌以革兰阴性菌为主;透析用水内毒素均2 EU/mL。结论目前重庆市大部分医院血液透析室的透析用水符合国家标准,但仍有部分医院透析液存在细菌污染。应定期检测透析用水、透析液中的内毒素和进行细菌培养,保障医疗安全。     

Surveillance and control of blood-borne virus infections in haemodialysis units

The risk of transmission of blood-borne viruses in renal dialysis units was reduced following the Rosenheim report recommendations issued in 1972. This document focused on the prevention and control of hepatitis B virus infections in renal dialysis and transplantation units. Good practice guidelines were produced, some of which may have been relaxed in conjunction with technological advances which included the use of disposable cartridges for haemodialysis. However, new viruses transmitted by blood and other body fluids have been identified over the years. A review of current practice for both patients and staff, together with updated good practice guidance, is necessary.     

Survey and significance of filamentous fungi from tap water

Fungi in drinking water are involved in the production of tastes and odours in water. Health problems are possible, originating from mycotoxins, animal pathogens and allergies. This report concerns the surveillance of mesophilic fungi in tap water and assessment of their potential for causing problems. The methods for the determination of the filamentous fungi (ff) were filtering, swabbing and baiting. Tap water, half-strength corn meal, neopeptone-glucose rose Bengal aureomycin (NGRBA) and oomycete selective agars for the enumeration of colony forming units (cfu) were used. Samples were taken consecutively over 16 months. Filtration and NGRBA gave the highest ff counts. A total of 340 taxa were isolated. There appeared to be a negative correlation between bacterial and yeast (b/y) and ff counts. Highest counts were found in winter months for ff and in the warmer months for b/y. Penicillium (40.6%) and Acremonium (38.8%) were the most frequently isolated ff. There was a difference in the pattern of isolation of the key taxa with season: penicillia predominated in early summer and Acremonium in winter. P. expansum was isolated in high numbers in May 2004. This species is associated with the production of the mycotoxin patulin and the odour secondary metabolite geosmin. P. brevicompactum was detected throughout the sampling period and is known to produce the immunosuppressive drug mycophenolic acid. Acremonium is associated with ocentol production which is responsible for bad tastes and flavours. The remaining taxa were Phialophora sp. (4.1%), Cladosporium sp. (3.5%), Rhizopus stolonifer (2.9%), Chaetomium sp. (0.6%), Alternaria sp. (0.3%), Aspergillus sp. (0.3%), mycelia sterilia (2.6%) and unidentified (6.2%). It is emphasised that few Aspergillus and no Fusarium strains were isolated. Rhizopus stolonifer was obtained. However, none of the fungi isolated at mesophilic temperature used could be described as being involved with pathogenicity per se.     

某市血液透析现状及透析用水和透析液质量合格情况调查

目的了解某市血液透析现状及透析用水和透析液合格情况。方法对该市36所开展血液净化项目的医疗机构血液透析现状进行调查,并同时采集透析用水及透析液分别进行微生物检验(包括常规和低温培养方法)及现场ATP水样检测。结果 13.89%的水处理设备使用时间在1年内,5.56%的设备使用超过10年。砂滤等净化设备超过1年未更换的机构占77.78%,72.22%的滤芯式过滤器更换时间3个月,反渗水供水管道使用时间超过10年的占2.78%。77.78%的医疗机构使用成品A液,72.22%使用成品B液,集中提供A液的医疗机构占22.22%,集中提供B液的医疗机构占19.44%,自配桶装B液的医疗机构达8.34%。36所医疗机构微生物日常检测均合格,但有80.56%检测结果长期为"0"值;现场采集的透析用水及透析液ATP检测均合格;常温微生物检验1份超标,2份达干预值;低温培养法4份超标,6份达干预值;不同级别医疗机构之间3种检测方法合格率比较,差异均无统计学意义(均P0.05)。结论该市透析用水及透析液的质量总体较好,大部分医疗机构重视水处理设备的日常维护,定期检测透析用水和透析液的质量,但是微生物检测技术有待提高,日常检测结果异常或达到干预值需要分析原因和不断改进。     

Infectious gastroenteritis in Norfolk Island and recovery of viruses from drinking water

A high incidence of gastroenteritis in both islanders and tourists has been recorded in recent years on Norfolk Island--a popular tourist resort for Australians and New Zealanders. No bacterial cause has been found. However, electron microscopic examination of 28 faecal specimens revealed viruses associated with gastroenteritis in 21 (75%). No viruses were isolated in cell cultures. Bore water is used for drinking purposes on the island and 32 samples from 15 bores were examined for viruses by electron microscopy and culture as well as for bacterial contamination. Seven polioviruses (all type 1 vaccine strain) and adenoviruses 1 and 5 were isolated in cell cultures. In addition one rotavirus, one adenovirus and two small round viruses were detected by electron microscopy. Six of 21 samples tested showed unacceptably high levels of bacteria for drinking water. The deep ground water has apparently become contaminated with sewage effluent and is almost certainly the main cause of the high level of gastroenteritis on the island.     

Comparison of apparent efficiency of haemodialysis satellite units in England and Wales using data envelopment analysis

OBJECTIVES: To expand care for chronic haemodialysis (HD) patients throughout England and Wales by studying two aspects of service delivery that are important: to identify relative performance of haemodialysis satellite units (HDSUs), and understand the factors that influence the performance. As a first step toward these aspects, this work reports a study of apparent comparative efficiency in the delivery of HDSUs and demonstrates the potential of data envelopment analysis (DEA). METHODS: DEA was applied to data obtained from a national survey of the organizational structures and processes of delivering care at HDSUs in England and Wales. RESULTS: DEA was found to be a judicious approach for performance assessment of HDSUs, although valid results depend on appropriate model specification and quality of data available. The available data were not of sufficient comprehensiveness or quality to produce definitive results but suggested that overall efficiency could improve; these data suggested by as much as 10% overall (mean efficiency score 90%) and variably within the sample (46 [65%] that HDSUs were potentially inefficient, the lowest unit scoring 38%). CONCLUSIONS: Addressing questions raised by comparative inefficiency could help plans to improve capacity to deal with the growing demand for HD delivered in HDSUs. The application was an important start and needs to be followed by further research to establish model validity and obtain authoritative results.     

Hepatitis C virus infection in four haemodialysis units of southern Italy: Epidemiological report

The haemodialysis patients are an high risk population for hepatitis viral infections. While the incidence of HBV has decreased worldwide, HCV is now the major cause of viral infection in these patients. The aim of our study was to define a complete map of patients undergoing routine replacement therapy by haemodialysis in the province of Foggia, Southern Italy, who were HCV Ab positive, the presence of viraemia and their genotypes; moreover, we investigated the probable factors involved in determining the infection as well as the means of prevention. Materials and methods: We enrolled 330 patients treated in four haemodialysis centres (DC) and six secondary units; mean age was 57 years and mean duration of dialysis 76 months. Samples were drawn to determine cytolysis indexes and the HCV Ab status; in HCV positive patients, we also looked for viraemia and HCV genotypes. Data were analysed by a transversal cross-section study. Results and conclusions: Prevalence of HCV infection was 0.43 (males 0.45, females 0.42). The risk of contracting the infection was shown to be significantly different in the various DCs and did not seem to be related to the severity of the preventive measures. There was no significant difference between the various DCs in the comparison between the odds of HCV-RNA+ and HCV-RNA– patients. No significant prevalence of a given genotype emerged from a cross-sectional study related to the comparison between different genotypes. Moreover, transfusions of blood products seemed to have no significant relation to HCV infection. Finally, patients treated with haemodialysis for more than 36 months run a seven time greater risk of contracting HCV infection.     

Recovery of filamentous fungi from water in a paediatric bone marrow transplantation unit

In order to determine whether water or water-related surfaces are a reservoir for opportunistic filamentous fungi, water sampling in the paediatric bone marrow transplantation (BMT) unit of the National Hospital University of Oslo, Norway was performed. During a six-month period 168 water samples and 20 samples from water-related surfaces were taken. The water samples were taken from the taps and showers in the BMT unit and from the main pipe supplying the paediatric department with water. In addition, 20 water samples were taken at the intake reservoir supplying the city of Oslo with drinking water. Filamentous fungi were recovered from 94% of all the water samples taken inside the hospital with a mean colony forming unit (cfu) count of 2.7/500mL of water. Aspergillus fumigatus was recovered from 49% and 5.6% of water samples from the taps and showers, respectively (mean 1.9 and 1.0cfu/500mL). More than one third (38.8%) of water samples from the main pipe revealed A. fumigatus (mean 2.1cfu/500mL). All water samples taken at the intake reservoir were culture positive for filamentous fungi, 85% of the water samples showed A. fumigatus (mean 3.1cfu/500mL). Twenty-five percent of water-related surfaces yielded filamentous fungi, but A. fumigatus was recovered from only two samples. We showed that filamentous fungi are present in the hospital water and to a lesser extent on water-related surfaces. The recovery of filamentous fungi in water samples taken at the intake reservoir suggests that the source of contamination is located outside the hospital.     

Infectious gastroenteritis in Norfolk Island and recovery of viruses from drinking water.

A high incidence of gastroenteritis in both islanders and tourists has been recorded in recent years on Norfolk Island--a popular tourist resort for Australians and New Zealanders. No bacterial cause has been found. However, electron microscopic examination of 28 faecal specimens revealed viruses associated with gastroenteritis in 21 (75%). No viruses were isolated in cell cultures. Bore water is used for drinking purposes on the island and 32 samples from 15 bores were examined for viruses by electron microscopy and culture as well as for bacterial contamination. Seven polioviruses (all type 1 vaccine strain) and adenoviruses 1 and 5 were isolated in cell cultures. In addition one rotavirus, one adenovirus and two small round viruses were detected by electron microscopy. Six of 21 samples tested showed unacceptably high levels of bacteria for drinking water. The deep ground water has apparently become contaminated with sewage effluent and is almost certainly the main cause of the high level of gastroenteritis on the island.     

三种用于血液透析和相关治疗用水微生物学监测方法的评价

目的评价三种方法用于监测血液透析和相关治疗用水微生物检测的效果。方法在某次飞行检查中采集36所受检单位的血液透析液和透析用水72份,分别采用血琼脂平皿(35℃,72 h)、胰蛋白酶大豆琼脂(TSA)平皿(35℃,72 h)、R2A营养琼脂(23℃,168 h)三种方法进行培养,比较三种方法菌落计数、菌落和超干预值(≥50 CFU/mL)检出率的差异。结果采用三种方法对透析液和透析用水进行检测,血琼脂平皿、TSA平皿、R2A营养琼脂菌落检出率分别为40.28%、63.89%和69.44%,差异有统计学意义(χ~2=14.16,P0.05);两两比较结果显示,R2A营养琼脂和TSA平皿检出率高于血琼脂平皿。血琼脂平皿与R2A营养琼脂、TSA与R2A营养琼脂检出菌落计数比较,差异有统计学意义(Z值分别为-4.515、-6.970,均P0.05)。血琼脂平皿、TSA平皿、R2A营养琼脂法检测透析液和透析用水菌落数,超干预值检出率分别为1.39%、4.17%和20.83%,差异有统计学意义(χ~2=19.83,P0.05),R2A营养琼脂检出率高于其他两种方法。结论 R2A营养琼脂和TSA平皿检出率优于血琼脂平皿,R2A营养琼脂超干预值检出率高于TSA平皿和血琼脂平皿,R2A营养琼脂(23℃,168 h)用于血液透析和相关治疗用水微生物监测优于其他两种方法。     

2013-2016年我国集中式供水卫生状况监督报告

目的 了解集中式供水卫生状况,为改善我国生活饮用水卫生提供科学依据。方法 采用描述性统计方法描述2013-2016年国家卫生监督信息报告系统采集的集中式供水单位不合格情况及2016年集中式供水单位不合格率的时间和空间分布;采用χ²检验比较不合格率的统计学差异。结果 2013-2016年我国监督检查的集中式供水单位不合格率分别为1.84%、2.73%、2.56%和2.74%。2016年集中式供水单位不同分类亚组的不合格率存在差异,差异均具有统计学意义（均有P<0.001）。乡镇（3.85%）较城市（1.74%）和自建设施（1.33%）不合格率高;中小型（2.40%）比大型（0.94%）不合格率高;气温高（4.52%）和降水量中等（3.73%）或高（2.36%）的地区不合格率高。夏季（2.06%）和秋季（2.60%）、西部（4.80%）和南方（4.01%）不合格率高。结论 我国乡镇、中小型及气温高和降水量偏多地区的集中式供水单位不合格率高,且不合格率呈季节和地区间差异。     

Keratinophilic fungi in waste water sediments]

In 21 samples of various kinds of waste water sediments derived from 10 waste water treatment plants of Upper Silesia, the occurrence of keratinophilic fungi was examined. A 2-year recultivation cycle of one of the sediments was investigated. Keratinophilic fungi were found to occur abundantly in waste water sediments. The qualitative and quantitative composition of these fungi depends on the origin and composition of waste water sediments, stabilization degree of their organic matter, hydration degree and structure. It was postulated that keratinophilic fungi may be utilized as microbiological indices of the transformations of organic matter of waste water sediments as well as of the degree of their deactivation from the sanitary standpoint. These fungi can be particularly useful upon utilization of the sediments for recultivation and fertilization of grounds.     

水冲洗法降低新旧牙科水道内细菌水平的效果比较

目的研究评估水冲洗法对新、旧牙科水道菌落总数及大肠埃希菌菌落数的影响。方法在8个新牙科单元使用约1年、12个旧牙科单元使用>10年的水道,分别在三用枪水道冲洗4 min、高速手机水道冲洗2 min前后,采集牙科单元水道的水样本,样本稀释后分别置于Petriflm AC培养板(检测菌落总数),和Petriflm EC培养板(检测大肠埃希菌菌落数),于37℃孵育48 h后计数菌落。结果牙科单元储水箱内过滤自来水的细菌含量较低(4~15 CFU/ml),但所有采自新、旧牙科单元水道的水样本均显示较高的细菌水平;冲洗水道使所有牙科单元水道的细菌含量下降,但新牙科单元比旧牙科单元水的细菌含量下降更多,两者差异有统计学意义(P<0.01)。结论水道冲洗是一项简便措施,能有效降低牙科水道内的细菌水平,对新牙科单元效果更佳。