Performance of retention soil filters for the reduction of hygienically-relevant microorganisms in combined sewage overflow and treated wastewater.

Environmental quality standards for surface waters have been significantly expanded through recent amendments to German regulations. Limit values are only established for applicable regulations if the water is indicated for certain uses, e.g. abstraction of irrigation water. Nevertheless, surface water bodies are often used for hygiene-sensitive purposes. In the course of climate change, stronger precipitation events will occur, which may lead to more frequent loading and discharge of combined sewer overflow (CSO) into surface water bodies. Retention soil filters (RSFs) are attracting attention as an extensive treatment technology for CSO and additional wastewater treatment. This study examined large-scale RSFs for CSO treatment, as well as the effectiveness of RSFs as a fourth purification stage. An RSF test facility was established at a municipal wastewater treatment plant (WWTP), consisting three semi-technical RSFs that were fed exclusively with treated water from the WWTP. The reduction of microorganisms mostly occurred within the first centimeters of the RSFs. For most hygienic-microbiological parameters, a 1-2 log unit reduction could be detected in addition to the reduction within the WWTP. Antibiotic-resistant bacteria were reduced to the same extent. Investigation of the large-scale RSFs showed that a flow rate reduced by half corresponded to better reduction performances.

Spatio-Temporal Distribution of Tuberculosis in an Urban Setting in Germany.

BACKGROUND: Big cities in Europe have the highest incidence rates of TB in otherwise low incidence settings. Understanding of the spatio-temporal patterns of TB incidence can support efforts for TB prevention and control in line with the End-TB Strategy of the WHO in such settings for low incidence settings. METHODS: Data from the municipal TB register of Cologne collected between 2006 and 2015 under the infection prevention legislation were retrieved, addresses geographically identified and all notified incident TB cases retrospectively analysed for their spatial and temporal distribution in this large German city using a geographic information system. RESULTS: During the analysed period 1,038 incident cases were reported, equivalent to an incidence rate of 10.03 cases per 100,000 inhabitants. Contagious pulmonary TB contributed 57 % of all cases. Distribution patterns changed over time with decreases in 37 and increases in 22 of the 77 urban sub-districts, three of which showing constant high rates of TB incidence. CONCLUSION: The study presents a complementary method to monitor the distribution and development of incident TB cases at a disaggregated level of urban sub-districts. Identification of areas with comparatively high incidence can support identification of clusters respectively their prevention and allow better planning for targeted local TB services.

[Identification of Systemic Contaminations with Legionella Spec. in Drinking Water Plumbing Systems: Sampling Strategies and Corresponding Parameters]. / Identifikation systemweiter Kontaminationen mit Legionella spec. in Trinkwasser-Installationen: Untersuchungsstrategien und korrespondierende Parameter.

After the amendment of the Drinking Water Ordinance in 2011, the requirements for the hygienic-microbiological monitoring of drinking water installations have increased significantly. In the BMBF-funded project "Biofilm Management" (2010-2014), we examined the extent to which established sampling strategies in practice can uncover drinking water plumbing systems systemically colonized with Legionella. Moreover, we investigated additional parameters that might be suitable for detecting systemic contaminations. We subjected the drinking water plumbing systems of 8 buildings with known microbial contamination (Legionella) to an intensive hygienic-microbiological sampling with high spatial and temporal resolution. A total of 626 drinking hot water samples were analyzed with classical culture-based methods. In addition, comprehensive hygienic observations were conducted in each building and qualitative interviews with operators and users were applied. Collected tap-specific parameters were quantitatively analyzed by means of sensitivity and accuracy calculations. The systemic presence of Legionella in drinking water plumbing systems has a high spatial and temporal variability. Established sampling strategies were only partially suitable to detect long-term Legionella contaminations in practice. In particular, the sampling of hot water at the calorifier and circulation re-entrance showed little significance in terms of contamination events. To detect the systemic presence of Legionella,the parameters stagnation (qualitatively assessed) and temperature (compliance with the 5K-rule) showed better results.

Retention of pharmaceutical residues and microorganisms at the Altendorf retention soil filter.

A study has been conducted on a retention soil filter (RSF) to test its effectiveness in removing pharmaceutical residues and microorganisms from combined sewer overflows (CSOs). Efficient removal of solids, nutrients and heavy metals has already been proven. The possibility that organic micropollutants and microorganisms are also retained by the use of RSFs has been identified, but data are lacking. Results obtained in this study, in which testing for removal by a RSF of numerous micro-pollutant substances was performed, are most promising. The pharmaceuticals diclofenac and ibuprofen are presented in detail as examples of such micropollutants. Both showed a reduction in positive samples of more than 55% as well as a significant reduction in median and maximum concentrations. For microorganisms such as Escherichia coli, coliphages and Giardia lamblia (cysts), an average reduction in concentrations by three logarithmic steps (99.9%) was achieved. These results add to the evidence that using a RSF in the advanced treatment of wastewater from CSOs reduces the exposure of water-courses to pharmaceutical residues and microbial contamination.

[Chances for health within the new water management]. / Chancen für die Gesundheit im neuen Gewässermanagement.

The European Water Framework Directive and the Protocol on Water and Health are two legally binding documents, which exist parallel to one another. A multi-disciplinary management of surface waters, which includes the participation of health experts, is necessary if the Protocol on Water and Health is to have an impact on human health rather than randomly promoting the effects of water management within the European Water Framework Directive.

Performance of a MBR for the treatment of blackwater.

The paper describes the experience gained in operating a membrane bioreactor (MBR) for the treatment of blackwater. Beside a complete characterization of blackwater, operational conditions and removal efficiency concerning parameters such as COD, BOD(5), nitrogen and phosphorus as well as microbiological parameters were determined. Furthermore the membrane performance was investigated. The results show that in blackwater treatment nitrogen removal is limited in the biological process, because of the blackwater matrix (BOD(5):TKN=1.1:1.0). Blackwater contains a high fraction of soluble, inert COD, which is not degradable by biological operation, only. Phosphorus elimination was negligible, probably induced by precipitation of cellular phosphorus. Although the released permeate was free of the fecal indicators E. coli and streptococcus and met guideline values, a direct reuse as service water is not recommended due to the yellowish coloration.

Association between antibiotic residues, antibiotic resistant bacteria and antibiotic resistance genes in anthropogenic wastewater - An evaluation of clinical influences.

The high use of antibiotics in human and veterinary medicine has led to a wide spread of antibiotics and antimicrobial resistance into the environment. In recent years, various studies have shown that antibiotic residues, resistant bacteria and resistance genes, occur in aquatic environments and that clinical wastewater seems to be a hot spot for the environmental spread of antibiotic resistance. Here a representative statistical analysis of various sampling points is presented, containing different proportions of clinically influenced wastewater. The statistical analysis contains the calculation of the odds ratios for any combination of antibiotics with resistant bacteria or resistance genes, respectively. The results were screened for an increased probability of detecting resistant bacteria, or resistance genes, with the simultaneous presence of antibiotic residues. Positive associated sets were then compared, with regards to the detected median concentration, at the investigated sampling points. All results show that the sampling points with the highest proportion of clinical wastewater always form a distinct cluster concerning resistance. The results shown in this study lead to the assumption that ciprofloxacin is a good indicator of the presence of multidrug resistant P. aeruginosa and extended spectrum ß-lactamase (ESBL)-producing Klebsiella spec., Enterobacter spec. and Citrobacter spec., as it positively relates with both parameters. Furthermore, a precise relationship between carbapenemase genes and meropenem, regarding the respective sampling sites, could be obtained. These results highlight the role of clinical wastewater for the dissemination and development of multidrug resistance.

Using Geographical Information Systems (GIS) as an instrument of water resource management: a case study from a GIS-based Water Safety Plan in Germany.

Following international developments and the new WHO Drinking Water Guidelines (WHO 2004) a process-orientated concept for risk, monitoring and incident management has been developed and implemented in this study. The concept will be reviewed with special consideration for resource protection (first barrier of the multi-barrier system) and in turn, for the Water Safety Plan (WSP) which adequately considers-beyond the current framework of legal requirements-possible new hygienic-microbiologically relevant risks (especially emerging pathogens) for the drinking water supply. The development of a WSP within the framework of risk, monitoring and incident management includes the application of Geographical Information Systems (GIS). In the present study, GIS was used for visualization and spatial analysis in decisive steps in the WSP. The detailed process of GIS-supported implementation included the identification of local participants and their tasks and interactions as an essential part of risk management. A detailed ecological investigation of drinking water conditions in the catchment area was conducted in addition to hazard identification, risk assessment and the monitoring of control measures. The main task of our study was to find out in which steps of the WSP the implementation of GIS could be integrated as a useful, and perhaps even an essential tool.

Perceptions of water, sanitation and health: a case study from the Mekong Delta, Vietnam.

In the Mekong Delta in the south of Vietnam about 5.7 million people lack access to safe drinking water and 10 million people in rural areas live without adequate sanitation. Between May and August, 2007 a survey was carried out in An Bin, a peri-urban ward in the Mekong Delta, to gain insight into water, sanitation and health as well as to health-related hygiene behaviour. The study employed a combination of quantitative (standardized questionnaire) and qualitative (focus group discussions, semi-structured interviews) methods. The most important features in the choice of drinking water sources are matters of hygiene and the taste of the water. The majority (74%) of the 120 households surveyed indicated their ownership of a sanitation facility, but the fish pond toilet (64%) which is predominantly utilized is considered to be unimproved sanitation. The local peri-urban population link water and hygiene to health, but sanitation instead to environmental pollution. This and other outcomes lead to the assumption that people have a basic knowledge of proper hygiene behaviour. However, hygiene measures such as hand washing are put into practice in an untimely manner, most likely due to a misconception of risks and/or a lack of background knowledge of cause-effect relationships as well as ingrained habits.

[Small-scale care by SHI physicians and their subjective choice of location within an oversupplied planning area]. / Kleinräumige kassenärztliche Versorgung und subjektives Standortwahlverhalten von Vertragsärzten in einem überversorgten Planungsgebiet.

OBJECTIVE: The aim of this study was to analyse whether geographical disparities exist in the outpatient care within the current planning districts of the German Association of SHI Physicians. Additionally, the motivation for the choice of a specific location by doctors was explored. METHODOLOGY: The study is based on two methods. Firstly on a geographical-statistical analysis of the ambulatory care in the study district (Rhein-Erft Distric), and secondly on a postal survey of the physicians. From a population of 619 physicians, 210 were chosen through a random sampling and sent a questionnaire. 117 physicians participated in the survey (rate of return: 55.7%). RESULTS: In the study district a considerable centre-periphery difference exists when considering ambulatory care. Even though the planning district is adequately supplied according to the rules of the German Association of SHI Physicians, there are postcode areas that are undersupplied with physicians. Some of the observed geographical heterogeneities proved to be statistically significant. The postal survey has shown that there are a variety of factors determining the choice of location of physicians. It was not possible to determine whether economic factors play a greater role than soft site-related factors. CONCLUSION: The results of the study indicate that the current requirements of the German Association of SHI Physicians are insufficient to solve the problem of grographically equal ambulatory care. Taking into account that economic motives for choice of location are not significant for the physicians on their own, geographical disparities cannot be eliminated by financial incentives only.

Hygiene and health - the need for a holistic approach.

The holistic principles of hygiene and public health have contributed substantially to an increase in life expectancy by more than 30 years and in life quality since the beginning of the 20th century. Frank, Pettenkofer, Nightingale, Pasteur, Lister, and Koch have been pioneering protagonists of the holistic approach to hygiene and public health. Socioeconomic development and related factors such as nutrition status and food hygiene, housing conditions, water supply and sewage systems, and education (including motivation for personal hygiene) have obviously been of more importance for life expectancy and life quality than progress in curative medicine, such as availability of microbial diagnosis, vaccination, and antibiotics. Today, new risk factors for infectious diseases arise, even in developed countries. These risk factors arise from emerging pathogens, antibiotic-resistant microorganisms, changing demographic patterns, an increasing amount of ambulatory and home care, socioeconomic and environmental changes, technical environments, worldwide distribution of food, and changing human behavior with a decreased awareness of microbial threats. These new challenges worldwide make a renewal of the holistic approach of hygiene and public health both urgent and necessary. On the basis of historic experience, policies that focus on surveillance and control, diagnosis, and therapy only can be assumed to be both insufficient and inefficient in controlling the new challenges in infectious diseases. Experiences in Germany with a holistic hospital hygiene strategy since 1976 provide encouragement for the promotion of holistic health concepts. Risk assessment, risk management, and risk communication are basic steps of a modern holistic strategy. Hygiene has the potential to act as a moderator of diverging positions of different disciplines within this renewed approach.

Disinfectant activity against different morphological forms of Helicobacter pylori: first results.

The pathogenic bacterium Helicobacter pylori, which has infected more than one-half of the world's human population, exists in two morphological forms; the viable helical form and the disputed viable-but-not-culturable coccoid form. Infection by the helical form proceeds through the oral-oral route, while that by the coccoid form, if possible at all, is by the faecal-oral and/or the oral-oral route. The present pilot study addresses the question of disinfectant efficacy against both forms of the bacterium.

The higher disinfectant resistance of nosocomial isolates of Klebsiella oxytoca: how reliable are indicator organisms in disinfectant testing?

The Children's Clinic in Giessen, Germany recently reported several severe infections with Klebsiella oxytoca resulting in deaths of two neonates. The putative source of the infections was a contaminated infusion solution. The resistance to disinfectant of the K. oxytoca isolates was investigated in three independent laboratories and was indeed found to be significantly increased. Comparative tests with standard strains of K. oxytoca and other recommended bacterial surrogates showed the disinfection procedures used were fully effective. The higher resistance of the nosocomial isolates may have developed due to improper handling and storage of the cleaning utensils. This report describes the events and draws conclusions concerning the use of disinfectants, the treatment of cleaning utensils, the reliability of procedures for testing disinfectants, and suggests additional measures.

A geographical information system (GIS) as a tool for microbial risk assessment in catchment areas of drinking water reservoirs.

The main tributaries of three drinking water reservoirs of Northrhine-Westfalia (Germany) were monitored within a 14-month period mainly for bacterial and parasitic contamination. In this context a detailed geo-ecological characterisation within the differing catchment areas was carried out to reveal a reliable informational basis for tracing back the origin of microbial loads present in the watercourses. To realise a microbial risk assessing geo-ecological information system (MRA-GIS), a Geographical Information System (GIS) has been implemented for the study areas. The results of the microbiological investigations of the watercourses showed an input of pathogens into all three of the tributaries. It could be demonstrated that the use of MRA-GIS database and some GIS-techniques substantially support the spatial analysis of the microbial contamination patterns. From the hygienic point of view, it is of the utmost importance to protect catchment areas of surface water reservoirs from microbial contamination stemming from human activities and animal sources. This constitutes essential part of the multi-barrier concept which stresses the importance of reducing diffuse and point pollution in catchment areas of water resources intended for human consumption. MRA-GIS proves to be helpful to manage multi-barrier water protection in catchment areas and ideally assists the application of the HACCP concept on drinking water production.

GIS-based analysis of drinking-water supply structures: a module for microbial risk assessment.

Water-related infections constitute an important health impact world-wide. A set of tools serving for Microbial Risk Assessment (MRA) of waterborne diseases should comprise the entire drinking-water management system and take into account the Hazard Analysis and Critical Control Point (HACCP) concept which provides specific Critical Control Points (CCPs) reflecting each step of drinking-water provision. A Geographical Information System (GIS) study concerning water-supply structure (WSS) was conducted in the Rhein-Berg District (North Rhine-Westphalia, Germany). As a result, suitability of the existing water databases HYGRIS (hydrological basis geo-information system) and TEIS (drinking-water recording and information system) for the development of a WSS-GIS module could be demonstrated. Spatial patterns within the integrated raw and drinking-water data can easily be uncovered by GIS-specific options. The application of WSS-GIS allows a rapid visualization and analysis of drinking-water supply structure and offers huge advantages concerning microbial monitoring of raw and drinking water as well as recognition and investigation of incidents and outbreaks. Increasing requests regarding health protection and health reporting, demands for a better outbreak management and water-related health impacts of global climate change are major challenges of future water management to be tackled with methods including spatial analysis. GIS is assumed to be a very useful tool to meet these requirements.

GIS-supported investigation of a nosocomial Salmonella outbreak.

Within an outbreak at a university hospital 102 persons (44 patients, 26 nursery school children and one relative as well as 31 employees) have been diagnosed to be infected by Salmonella enteritidis. Ninety-nine persons complied with the "primary case"-definition. The source of infection could not be detected in retrospect by hygienic-microbiological methods due to missing food samples. But GIS (Geographical Information System)-supported epidemiological investigation and analysis of food production showed that most likely vanilla pudding had been the vehicle of infection. Contamination of the pudding could be put down to the fact that its production took place in direct spatial and temporal association with the preparation of turkey. Probably further infections caused by this primary source were avoided by immediate measures. The making out of an HACCP-concept as well as structural and technical short-term redevelopment measures proved to be decisive factors to decrease the risk of further infections. From these experiences, some recommendations could be derived for the investigation of food-borne outbreaks in hospitals.

The human ecology of malaria in a highland region of South-West Kenya.

OBJECTIVE: This study assessed interactions between human beings and their immediate micro-ecological environment with regard to malaria transmission at the household level. METHODS: Malaria cases and their controls were sampled from a local health care facility. A spot check of potential risk factors for malaria around the subjects' dwelling places was done. A standardized questionnaire was administered to investigate human behavior that could lead to increased risk of malaria. RESULTS: Outdoor activities at night, living in houses with eaves, keeping cattle close to human dwellings and presence of stagnant water around the homesteads were associated with increased risk of malaria. CONCLUSION: Living in houses with open eaves and being out at night were found to influence malaria incidences at household level.

[Water as a reservoir for nosocomial infections in health care facilities, prevention and control]. / Wasser als Infektionsquelle in medizinischen Einrichtungen, Prävention und Kontrolle.

New epidemiological and microbiological investigations using molecular typing methods to link patient and environmental strains demonstrate a strong association between water-borne pathogens and nosocomial infections. Avoiding patient exposure to these pathogens results in a decreased incidence of water-borne nosocomial infections. There remains a tremendous potential to reduce hospital acquired infections previously viewed as inevitable and unavoidable through intervention and preventive measures. The characteristics of water application in health care facilities, the vulnerability of patients, the spectrum of relevant pathogens and their ecologic aspects, legal issues and important measures for prevention and control are discussed.

[Significance of the ordinance on the quality of water for human consumption (Drinking Water Ordinance 2001) for hospital hygiene]. / Bedeutung der Verordnung über die Qualität von Wasser für den menschlichen Gebrauch (Trinkwasserverordnung 2001) für die Krankenhaushygiene.

Since January 2003, the new German Drinking Water Ordinance (DWO) has become operative. This paper briefly reviews some major consequences for hospitals. One of the main topics is the increased responsibility of operators of drinking water installation systems in hospitals concerning both the maintenance and control of good drinking water quality. Besides harmful chemical parameters, proliferation of pathogens can occur such as Pseudomonas aeruginosa, Legionella spec., Acinetobacter, and others which are mainly bound to biofilms and thus less affected by disinfectants. Recent epidemiological investigations point out that the relevance of waterborne pathogens is still considerably underestimated, particularly in hospitals. Local public health authorities play a central role in clinic inspection, supervision of water installations, surveillance, and risk assessment in cases of noncompliance with DWO requirements. For this reason, every irregularity detected must be reported to the local public health authority.

Association between environmental risk factors and campylobacter infections in Sweden.

Campylobacter sp. is the most common cause of acute bacterial gastroenteritis in Sweden and the incidence has been increasing. Case-control studies to identify risk factors have been conducted in several countries, but much remains unexplained. The geographical distribution of campylobacter infections varies substantially, and many environmental factors may influence the observed pattern. Geographical Information Systems (GIS) offer an opportunity to use routinely available surveillance data to explore associations between potential environmental risk factors showing a geographical pattern and disease incidence, complementing traditional approaches for investigating risk factors for disease. We investigated associations between campylobacter incidence and environmental factors related to water and livestock in Sweden. Poisson regression was used to estimate the strength of the associations. Positive associations were found between campylobacter incidence and average water-pipe length per person, ruminant density, and a negative association with the percentage of the population receiving water from a public water supply. This indicates that drinking water and contamination from livestock may be important factors in explaining sporadic human campylobacteriosis in Sweden, and that contamination occurring in the water distribution system might be more important than previously considered.