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Coastal habitats provide important ecosystem services, such as the maintenance of ecological sustainability, water quality regulation, nutrient recycling, and sandy beaches which are important areas for recreation and tourism. The quality of seawater is generally measured by determining the concentrations of Escherichia coli and intestinal Enterococci, which might be affected by the persistent populations of these bacteria in sand. Sand might thus be a significant source of pathogen exposure to beachgoers. The quality of coastal recreational waters can also be affected by eutrophication, water discoloration, and harmful algal blooms, which pose additional human health risks. Here, we conducted a monitoring of the beaches quality along the Taranto Gulf by determining the concentrations of fecal indicator organisms, as well as other parameters that are not traditionally measured (physicochemical parameters, Pseudomonas aeruginosa, and harmful microalgae), in shallow seawater and sand sampled from three beaches. The concentrations of bacteria were determined using both standard microbiological methods and the IDEXX system. Our results demonstrate the utility of measuring a greater number of parameters in addition to those conventionally measured, as well as the importance of assessing the health risks posed by the sand matrix. Additional work is needed to develop rapid analytical techniques that could be used to monitor the microbiological parameters of solid matrices., (© 2022. The Author(s).)

The use of antiseptics for the removal of bacteria in water has become pertinent given that most hand dug wells, boreholes, and surface waters are already contaminated in their in situ condition before being used. But, the efficacy of these skin disinfectants (antiseptics) is usually not well spelt out for the aforementioned purpose, and usage may yield no good report. This study assessed the suitability of use of two widely used antiseptics in Nigeria (Dettol and Izal) on Bacillus spp., Escherichia coli and Klebsiella spp., in eliminating bacteria in bathing water. The water which were tested at four different concentrations (0.4 ml, 0.8 ml, 1.2 ml, and 1.6 ml) and at six different contact times (0, 5, 10, 15, 30, and 60 min, respectively) within which bathing is meant to take place after antiseptics were applied. Overall, One hundred and Forty-four (144) samples were analyzed, and based on our null hypothesis of no bacteria should be found in bathing water after disinfection, results showed that both antiseptics were not efficient in bacteria removal. However, the multivariable logistic regression model conducted revealed that both antiseptics were more active in destroying Klebsiella spp. than any other bacteria investigated with Izal showing more dominance (OR = 31.21; p < 0.05). The study further revealed that Izal is 3.6 times more likely to destroy bacteria than Dettol (p < 0.05), with more of the elimination occurring at contact time greater than 5 min (OR = 1.504; p = 0.043). Therefore, it is suggested that disinfectants and antiseptics of high motility and sufficient potency in a wide range of bacteria spectrum should be produced to meet the needs of consumers resulting in a better bathing water quality.

The Bi-SnO 2 /C electrocatalytic membrane was fabricated via a simple electrochemical reduction and hydrothermal method. Under the action of electric field, the Sn 2+ and Bi 3+ were firstly adsorbed and reduced to metallic Sn and Bi on the carbon membrane surface by cathodic reduction reaction, and the Bi-SnO 2 /C membrane was obtained subsequently through hydrothermal oxidation process. Confirmed by SEM, TEM, XRD, and XPS characterizations, the nano-Bi-SnO 2 is homogeneously distributed on the membrane surface and is firmly attached to the carbon membrane via C-O-Sn chemical bond. Through CV, LSV, and EIS electrochemical analysis, the Bi-SnO 2 /C membrane possesses the higher electrocatalytic activity and stability than carbon membrane. Therefore, the Bi-SnO 2 /C membrane could continuously efficiently remove and inactivate Escherichia coli in water through flow-through mode. As a result, the sterilization efficiency can reach more than 99.99% under the conditions of cell voltage 4 V, flow rate 1.4 mL/min, and E. coli initial concentration 1.0 × 10 4  CFU/mL, owing to the synergistic effect of the membrane separation and electrocatalytic oxidation. Moreover, it was found that the oxidation groups of ⋅OH radicals generated by Bi-SnO 2 /C membrane play the crucial role for bactericidal performance. This work presents a low-cost, highly active, and stable electrocatalytic membrane towards continuous bacterial inactivation, which exhibits promising potential in water disinfection and is beneficial for practical large-scale applications.

Understanding the abundance and fate of human viral pathogens in wastewater is essential when assessing the public health risks associated with wastewater discharge to the environment. Typically, however, the microbiological monitoring of wastewater is undertaken on an infrequent basis and peak discharge events may be missed leading to the misrepresentation of risk levels. To evaluate diurnal patterns in wastewater viral loading, we undertook 3-day sampling campaigns with bi-hourly sample collection over three seasons at three wastewater treatment plants. Untreated influent was collected at Ganol and secondary-treated effluent was sampled at Llanrwst and Betws-y-Coed (North Wales, UK). Our results confirmed the presence of human adenovirus (AdV), norovirus genotypes I and II (NoVGI and NoVGII) in both influent and effluent samples while sapovirus GI (SaVGI) was only detected in influent water. The AdV titre was high and relatively constant in all samples, whereas the NoVGI, NoVGII and SaVGI showed high concentrations during autumn and winter and low counts during the summer. Diurnal patterns were detected in pH and turbidity for some sampling periods; however, no such changes in viral titres were observed apart from slight fluctuations in the influent samples. Our findings suggest that viral particle number in wastewater is not affected by daily chemical fluctuations. Hence, a grab sample taken at any point during the day may be sufficient to enumerate the viral load of wastewater effluent within an order of magnitude while four samples a day are recommended for testing wastewater influent samples.

The study aims to evaluate the microbial contamination in dental unit water system (DUWS) in Chandigarh, India, including knowledge, attitude, and practices of general dental practitioners (GDPs) to reduce the microbiological risks of DUWS. Microbiological risks were assessed by collecting water samples from 18 dental chair units including three main water supply units. Total of 44 water samples were examined for bacteriological contamination and the highest microbial contamination was observed in the ultrasound scalers having a range of 100 to 12,000 CFU/ml, with a median count of 950 CFU/ml. Only 2.3% of the water samples met the European Union recommendation of less than 100 CFU/ml, whereas 97.7% of the water samples have the total bacterial count exceeding 100 CFU/ml. In comparison to Center for Disease Control (CDC) guidelines, only 20.5% water samples fall within the recommended quality of drinking water (less than 500 CFU/ml), and the rest of the samples (79.5%) exceed the total bacteria count with a median count of 1100 CFU/ml. Acinetobacter species, Pseudomonas aeruginosa, and Sphingomonas paucimobilis were found in most of the water samples from DUWS. Dental chair units show higher microbial load and hence failed to meet any international guidelines, e.g., CDC. The highest microbial contamination was observed in ultrasound scaler and air/water syringe outlets. Hence, the study demand for Indian guidelines for the type of water used in DUWS water and urges for the proper training of GDPs to avoid further risks to the dental patients.

Contamination of drinking water in household water storage containers and inadequate water supplies are common public burdens in low- and middle-income countries, including towns in Wegera District, Ethiopia. Our study aimed to assess the quality of drinking water and identify factors associated with diarrhea in households with under-five (U5) children with and without diarrhea in Ambagiorgis and Gedebge towns in Wegera District. Stored drinking water samples from households with U5 children with and without diarrhea had fecal coliform (FC) counts of 59 (86.8%) and 55 (82.1%) (p > 0.05) and fecal streptococci (FS) counts of 29 (42.7%) and 24 (35.8%) (p > 0.05), respectively. The very high sanitary risk scores were 32 (47.1%) and 21 (31.3%) for FC (p > 0.05); 25 (36.8%) and 3 (4.5%) for FS (p < 0.001), respectively. Contamination of the stored drinking water samples with FS was significantly higher in households with diarrhetic U5 children in the low- and medium-risk ranges (p < 0.05). Water turbidity of 47 (69.1%) and 23 (34.3%) in households with U5 children with and without diarrhea, respectively, was above the permissible level (p < 0.001). The residual free chlorine (RFC) in all the household-stored drinking water samples was below the World Health Organization (WHO) permissible level and temperatures of all the household-stored drinking water samples were permissible. Promotion and advocacy of good stored drinking water handling practices are essential for decreasing the high risk of microbial contamination in both study areas. We recommend education interventions targeting personal hygiene and drinking water handling at the household level.

Cholera is a global public health problem with high endemicity in many developing countries in Africa. In 2014, Ghana experienced its largest epidemic with more than 20,000 cases and 200 deaths; most of it occurred in the Accra Metropolitan Area (AMA). Ghana's disease surveillance system is mainly clinically based and focused on case detection and management. Environmental exploration for the etiological agents is missing from the surveillance strategy. This study therefore assessed the occurrence of toxigenic Vibrio cholerae in water storage systems in selected high risk areas in the AMA area prior to the 2014 outbreak. Three hundred twenty water samples from 80 households' water storage systems were analyzed for toxigenic Vibrio cholerae using the bacterial culture method. Presumptive V. cholerae was isolated from 83.8% of households' water storage systems. The viable cells ranged from 1 to 1400 CFU/100 ml. Vibrio cholerae O1 serotype was isolated from five households in Old Fadama, one household in Shiabu, and one household in Bukom in the month of May and a similar trend was observed for the months of June and July. The presence of Vibro cholerae in the water storage vessels used for drinking confirms the need to consider environmental surveillance for toxigenic Vibro cholerae particularly in high-risk areas to strengthen the existing surveillance system.

Burkholderia pseudomallei causes melioidosis, a life-threatening infection in both humans and animals. Water is an important reservoir of the bacteria and may serve as a source of environmental contamination leading to infection. B. pseudomallei has an unusual ability to survive in water for a long period. This paper investigates physicochemical properties of water associated with the presence of B. pseudomallei in water supply in small ruminant farms in Peninsular Malaysia. Physicochemical properties of water samples taken from small ruminant farms that included temperature, pH, dissolved oxygen (DO 2 ), optical density (OD), and chemical oxygen demand (COD) were measured after which the samples were cultured for B. pseudomallei. Multivariable logistic regression model revealed that slightly acidic water pH and higher COD level were significantly associated with the likelihood of the B. pseudomallei presence in the water.

Roof-harvested rainwater (RHRW) has been used as an alternative source of water in water scarce regions of many countries. The microbiological and chemical quality of RHRW has been questioned due to the presence of bacterial and protozoan pathogens. However, information on the occurrence of pathogenic amoeba in RHRW tank samples is needed due to their health risk potential and known associations with opportunistic pathogens. Therefore, this study aims to determine the quantitative occurrence of Naegleria fowleri in RHRW tank samples from Southeast Queensland (SEQ), Australia (AU), and the Kleinmond Housing Scheme located in Kleinmond, South Africa (SA). In all, 134 and 80 RHRW tank samples were collected from SEQ, and the Kleinmond Housing Scheme, Western Cape, SA, respectively. Quantitative PCR (qPCR) assays were used to measure the concentrations of N. fowleri, and culture-based methods were used to measure fecal indicator bacteria (FIB) Escherichia coli (E. coli) and Enterococcus spp. Of the 134 tank water samples tested from AU, 69 and 62.7% were positive for E. coli, and Enterococcus spp., respectively. For the SA tank water samples, FIB analysis was conducted for samples SA-T41 to SA-T80 (n = 40). Of the 40 samples analyzed from SA, 95 and 35% were positive for E. coli and Enterococcus spp., respectively. Of the 134 water samples tested in AU, 15 (11.2%) water samples were positive for N. fowleri, and the concentrations ranged from 1.7 × 10 2 to 3.6 × 10 4 gene copies per 100 mL of water. Of the 80 SA tank water samples screened for N. fowleri, 15 (18.8%) tank water samples were positive for N. fowleri and the concentrations ranged from 2.1 × 10 1 to 7.8 × 10 4 gene copies per 100 mL of tank water. The prevalence of N. fowleri in RHRW tank samples from AU and SA thus warrants further development of dose-response models for N. fowleri and a quantitative microbial risk assessment (QMRA) to inform and prioritize strategies for reducing associated public health risks.

Monitoring drinking water quality is an important public health issue. Two objectives from the 4 years, six nations, EU Project μAqua were to develop hierarchically specific probes to detect and quantify pathogens in drinking water using a PCR-free microarray platform and to design a standardised water sampling program from different sources in Europe to obtain sufficient material for downstream analysis. Our phylochip contains barcodes (probes) that specifically identify freshwater pathogens that are human health risks in a taxonomic hierarchical fashion such that if species is present, the entire taxonomic hierarchy (genus, family, order, phylum, kingdom) leading to it must also be present, which avoids false positives. Molecular tools are more rapid, accurate and reliable than traditional methods, which means faster mitigation strategies with less harm to humans and the community. We present microarray results for the presence of freshwater pathogens from a Turkish lake used drinking water and inferred cyanobacterial cell equivalents from samples concentrated from 40 into 1 L in 45 min using hollow fibre filters. In two companion studies from the same samples, cyanobacterial toxins were analysed using chemical methods and those dates with highest toxin values also had highest cell equivalents as inferred from this microarray study.

Antibiotic resistance genes (ARGs) in urban rivers are a serious public health concern in regions with poorly planned, rapid development. To gain insights into the predominant factors affecting the fate of ARGs in a highly polluted urban river in eastern China, a total of 285 ARGs, microbial communities, and 20 physicochemical parameters were analyzed for 17 sites. A total of 258 unique ARGs were detected using high-throughput qPCR, and the absolute abundance of total ARGs was positively correlated with total organic carbon and total dissolved nitrogen concentrations (P < 0.01). ARG abundance and diversity were greatly altered by microbial community structure. Variation partitioning analysis showed that the combined effects of multiple factors contributed to the profile and dissemination of ARGs, and variation of microbial communities was the major factor affecting the distribution of ARGs. The disparate distribution of some bacteria, including Bacteroides from mammalian gastrointestinal flora, Burkholderia from zoonotic infectious diseases, and Zoogloea from wastewater treatment, indicates that the urban river was strongly influenced by point-source pollution. Results imply that microbial community shifts caused by changes in water quality may lead to the spread of ARGs, and point-source pollution in urban rivers requires greater attention to control the transfer of ARGs between environmental bacteria and pathogens.

Human adenoviruses (HAdVs) are DNA viruses found in recreational water, such as water parks and swimming pools. Human adenovirus 41 (HAdV-41) is the most common serotype detected and is a leading cause of acute diarrheal disease. The focus of this study is to determine the prevalence of HAdVs in hot springs. Of 57 samples collected from four different geological sites, 16 samples have shown evidence of HAdVs (28.1%). HAdV-41 and porcine adenovirus 5 (PAdV-5) were the two types isolated, with a greater frequency of HAdV-41, which in other settings has been associated with acute diarrhea. The highest occurrence was found in private hot tubs/Yuya (37.5%), followed by an outlet of hot springs (30.8%); public pools and foot pools shared the same detection rate of 21.4% (3/14). However, there was no evidence supporting a link between water quality indicators and HAdV detection rate. From a phylogenic analysis and BLAST against the NCBI database, it was concluded that HAdV-41 obtained from hot spring areas are closely related to global environmental genotypes.

Swimming pools have been identified as posing some public health risks to users due to either bacterial or chemical contamination. As a result, maintaining good swimming pool water quality is an important issue in preventing health risks for bathers. This study aimed to evaluate the bacteriological quality of some swimming pools in Alexandria and to investigate the prevalence of Staphylococcus aureus (S. aureus) in water samples. A total of 120 water samples from 10 swimming pools were collected. Bacteriological analysis included heterotrophic plate count (HPC) using pour plate method; enumeration of total coliforms (TC), Escherichia coli (E. coli) and S. aureus by membrane filtration technique. Antimicrobial susceptibility testing was performed on isolated S. aureus. Residual chlorine and pH were measured at swimming pools side. HPC was the least complying microbial parameter, followed by TC. S. aureus was recovered from 18 samples; 9 isolates were methicillin resistant S.aureus (MRSA), compared to E. coli that was detected in 7 samples. HPC and TC showed statistically significant correlations with all investigated parameters. In conclusion, the examined pools showed poor quality regarding all examined parameters collectively according to the Egyptian guidelines, which necessitates implementation of proper measures to ensure safer environment in swimming pools.

Pollutants in marine coastal areas are mainly a consequence of anthropogenic inputs, and microorganisms often play a major role in determining the extent of this pollution. Thus, practical and eco-friendly techniques are urgently required in order to control or minimise the pathogenic bacterial problem. The bacterial accumulation of Mytilus galloprovincialis (Lamarck 1919) in the presence or absence of another filter feeder, the demosponge Hymeniacidon perlevis (Montagu 1818) on sewage flowing into the Northern Ionian Sea has been estimated in a laboratory study. On account of the interesting results obtained, we also evaluated the bioremediation capability of the sponges when reared in co-culture with mussels. Specimens of M. galloprovincialis and H. perlevis were collected from the Mar Grande and from the Second Inlet of the Mar Piccolo of Taranto (Northern Ionian Sea, Italy), respectively. In the laboratory, we detected the bacterial abundances in the sewage, in sponge homogenates (both sponges alone and sponges that have been added to sewage with mussels) and in mussel homogenates (both mussels alone and mussels that have been added to sewage with sponges). In the field, we estimated the bacterial concentration in both the seawater within the mussels culture and the seawater collected where mussels were reared in co-culture with sponges. The bacteriological analyses were performed analysing the following parameters: the density of culturable heterotrophic bacteria by spread plate on marine agar, total culturable bacteria at 37 °C on plate count agar and vibrios on thiosulphate-citrate-bile-sucrose-salt (TCBS) agar. Total coliforms, Escherichia coli and intestinal streptococci concentrations were detected by the MPN method. The study demonstrates a higher efficiency of the sponges in removing all the considered bacterial groups compared to the mussels. Due to the conspicuous bacterial accumulation by the sponge, we can conclude that the co-occurrence of the filter-feeder H. perlevis with M. galloprovincialis is a powerful tool in reducing the bacterial load in shellfish culture areas thus playing a role in mitigating the health hazard related to the consumption of edible mussels.

Cyanobacterial contamination of public water supply systems is a worldwide problem. The present study investigated water quality and microcystins (MCs) contamination of four public water supply systems in Zaria, Nigeria. The water bodies were eutrophic in the rainy and dry season and supported high phytoplankton biomass with chlorophyll a concentrations generally higher than 20.0 μg/L. The biomass of the predominant species (Microcystis aeruginosa and Anabaena subcylindrica) of cyanobacteria had a significant positive correlation with particulate and dissolved MCs. Dissolved MCs concentrations were higher (>1.0 μg/L) than the maximum permissible limits for drinking water in all the water bodies in the dry season and three of them in the rainy season. These results suggest that there is the need to have a regular monitoring program for these water bodies to prevent acute and chronic health hazards associated with MCs contamination of drinking and irrigation water.

Biosand filters in the Artibonite Valley of Haiti, the epicenter of the cholera epidemic that began in October 2010, were tested for total coliform and Vibrio cholerae removal efficiencies. While coliform are often used as an indicator organism for pathogenic bacteria, a correlation has never been established linking the concentration of coliform and V. cholerae, the causative agent for cholera. Hence, a method for field enumeration of V. cholerae was developed and tested. To this end, a plate count test utilizing membrane filtration technique was developed to measure viable V. cholerae cell concentration in the field. Method accuracy was confirmed by comparing plate count concentrations to microscopic counts. Additionally, biosand filters were sampled and removal efficiencies of V. cholerae and coliform bacteria compared. The correlation between removal efficiency and time in operation, biofilm ("schmutzdecke") composition, and idle time was also investigated. The plate count method for V. cholerae was found to accurately reflect microscope counts and was shown to be effective in the field. Overall, coliform concentration was not an appropriate indicator of V. cholerae concentration. In 90% of the influent samples from the study, coliform underestimated V. cholerae concentration (n = 26). Furthermore, coliform removal efficiency was higher than for V. cholerae hence providing a conservative measurement. Finally, time in operation and idle time were found to be important parameters controlling performance. Overall, this method shows promise for field applications and should be expanded to additional studies to confirm its efficacy to test for V. cholerae in various source waters.

Wetlands provide many valuable ecosystem services, including water quality improvement to protect downstream aquatic ecosystems such as lakes, rivers, and estuaries. However, their ability to improve water quality to safe levels for direct human exposure while largely surrounded by agricultural lands and hosting large wildlife populations remains unknown. Our aim was to examine the ecosystem service capabilities of an avian-dense coastal wetland surrounded by agricultural lands along the southwestern shore of Lake Erie in Ohio by assessing the quality of water as it flows through the wetland (Ottawa National Wildlife Refuge (ONWR)) and into Lake Erie beach waters. Our study used total phosphorus and fecal indicator (Escherichia coli) concentrations as water quality metrics across the wetland and at an adjacent Lake Erie swimming beach during the 2012 summer swim season. E. coli and total P levels were consistently highest at the site, where water enters the ONWR (mean E. coli = 507 CFU/100 mL; mean total P = 535 μg/L), and steadily decreased as water flowed through the wetland and into the adjacent beach (mean E. coli = 10 CFU/100 mL; mean total P = 41 μg/L). E. coli and total P showed statistically significant (α = 0.01) correlations with phycocyanin, chlorophyll-a, turbidity, specific conductivity, dissolved oxygen, and pH; total P was also significantly correlated with total N. The results suggest that this wetland may be contributing to improving water quality, which is beneficial for human health as well as to downstream ecosystem health (e.g., limiting eutrophication promoting conditions, etc.).

As little is known about the potential risks associated with the use of microbiologically contaminated river water for recreation, irrigation, or domestic purposes, the Msunduzi River in Pietermaritzburg (KwaZulu-Natal, South Africa) was evaluated. In addition to pH, temperature, and chemical oxygen demand, quantitative and qualitative microbiological analyses were performed monthly for 13 months. These included aerobic plate counts, counts of aerobic and anaerobic sporeformers, most probable numbers for total and faecal coliforms and Escherichia coli and the detection of Salmonella spp., Staphylococcus aureus, and intestinal enterococci. Presumptive E. coli and S. aureus from river water samples were confirmed using PCR and additionally matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) for E. coli. Aerobic plate counts were above the South African Department of Water Affairs recommended guideline level for domestic use of 100 cfu/ml for all 13 months assessed. Faecal coliform (up to 63,000 MPN/100 ml) and E. coli (up to 7,900 MPN/100 ml) levels regularly exceeded stipulated limits for safe irrigation, domestic and recreational use. The presence of Salmonella spp., S. aureus, and intestinal enterococci frequently coincided with faecal coliform and E. coli levels above 1,000 MPN/100 ml. This illustrates the value of using guideline values for faecal coliforms and E. coli as indicators for the presence of potential pathogens. PCR and MALDI-TOF MS confirmation of E. coli were in agreement, thereby demonstrating the potential of MALDI-TOF MS as a suitable alternative. These data demonstrate that potential health risks are associated with using Msunduzi River water for irrigation and recreational or domestic purposes.

Purpose: The aim of this paper was to develop a new recreational water quality index (RWQI) as a tool to ensure the health of swimmers and to take practical decisions., Methods: RWQI was elaborated with epidemiological data, and we carried out an exhaustive study of the different guidelines for recreational waters proposed by different organisations around the world. Different parameters were chosen, considering, as a priority, the swimmer's contact and the possibility of ingestion of water during the recreational activity. Furthermore, rating curves were established for pH, chemical oxygen demand, nitrate, phosphate, detergents, enterococci, total coliforms, faecal coliforms and Escherichia coli., Results and Conclusions: The index was applied to the data set on water quality of the Potrero de los Funes River (San Luis, Argentina), generated during 2 years (2009-2010). Following the RWQI values classification, most of the Potrero de los Funes water samples fell in the good quality range during the study period.

Anthropogenic activities associated with industrialization, agriculture and urbanization have led to the deterioration in water quality due to various contaminants. To assess the status of urban drinking water quality, samples were collected from the piped supplies as well as groundwater sources from different localities of residential, commercial and industrial areas of Lucknow City in a tropical zone of India during pre-monsoon for estimation of coliform and faecal coliform bacteria, organochlorine pesticides (OCPs) and heavy metals. Bacterial contamination was found to be more in the samples from commercial areas than residential and industrial areas. OCPs like α,γ-hexachlorocyclohexane and 1,1 p,p-DDE {dichloro-2, 2-bis(p-chlorophenyl) ethene)} were found to be present in most of the samples from study area. The total organochlorine pesticide levels were found to be within the European Union limit (0.5 μg/L) in most of the samples. Most of the heavy metals estimated in the samples were also found to be within the permissible limits as prescribed by World Health Organization for drinking water. Thus, these observations show that contamination of drinking water in urban areas may be mainly due to municipal, industrial and agricultural activities along with improper disposal of solid waste. This is an alarm to safety of public health and aquatic environment in tropics.

Pseudomonas aeruginosa (P. aeruginosa) is a relevant pathogen to bathers and, therefore, water from natural swimming pools is analyzed for its presence. P. aeruginosa can be detected regularly in surface waters. Currently the methods described in DIN EN 12780 are recommended for the quantitative analysis of water from natural swimming pools, although this standard was developed for bottled water. The present study examines whether the recommendation is satisfactory. In 93 water samples from five natural swimming pools (Naturschwimmteiche), 3226 presumptive P. aeruginosa colonies were detected. Of the 3226 colonies, 101 were directly confirmed due to their formation of pyocyanin. From the remaining 3125 colonies, 349 representative samples were isolated and examined further. Using the criteria of DIN EN 12780 fluorescense and ammonia formation from acetamide, another 45 colonies were considered to be P. aeruginosa. 71% (32) of these 45 non-pyocyanin-forming strains could not be confirmed by the APINE system. None of the 32 strains grew at 42 degrees C, which is a characteristic feature of P. aeruginosa as mentioned in a note of DIN EN 12780. In 20 of the original samples, P. aeruginosa numbers exceeded the recommended limit value of 10/100 ml. Eleven cases (55 %) were caused by P. aeruginosa, which were not confirmed taxonomically. Due to insufficient selectivity, the method according to DIN EN 12780 is not applicable for the testing of surface waters and water from natural swimming pools. The high number of false positive results for P. aeruginosa questions the standard even further. It is suggested that for surface water samples growth of P. aeruginosa at 42 degrees C has to be checked as an additional confirmation characteristics of P. aeruginosa until a reliable standard is published.

"Bathing ponds" are artificial outdoor water pools without disinfection. Whereas in conventional pools, chlorine promptly kills pathogens shed by bathers, such quick inactivation is missing in bathing ponds. We have explored the retention of indicator bacteria and viruses by a vertically operated, reed grown soil filter. After continuously running the filter with wastewater-spiked surface water, we found that the filter retains more than 99 % of the indicator organisms. It has been reported in the literature that the "spontaneous" inactivation of pathogens in water might be very variable depending on sunlight irradiation, water turbidity, etc. On the contrary, the performance of a filter like the one reported here allows filtering the water so as to reliably eliminate 90 % of the spiked microorganisms from the pool water within 24 hours.

Legionella bacteria colonize drinking water systems and can cause severe pneumonia in humans (Legionnaires' disease (LD)). The German network for community-acquired pneumonia (CAPNETZ) estimates 15,000-30,000 new cases of LD per year in Germany. LD cases are divided into those that were acquired in the context of a stay in a hospital or nursing home (healthcare-associated; HCA), in the community (community-acquired (CA)) or during travel (travelassociated (TA)). According to the recommendations of the Communicable Disease Surveillance Centre (CDSC; UK) and the Healthcare Infection Control Practices Advisory Committee (HICPAC; USA) a single case of nosocomial LD should prompt an epidemiologic and, depending on its results, also technical investigation of the institution. In this study we present data from nosocomial cases of LD in the context of all cases of LD that were reported to the Robert Koch Institute (RKI) within the mandatory surveillance system from 2004 through 2006. We calculated the number of cases per population (incidence), the number of cases per person-days at risk (incidence rate) and case fatality. The analysis comprised 1,339 cases of LD. Among the 942 cases with one of the three categories of exposure CALD was reported in 58 % (547 cases), TALD in 29 % (270 cases) and HCA-LD in 13 % (125 cases). The incidence rate of TALD was 9-fold, but that of HCA-LD 15-fold higher than that of CALD. Case fatality of HCA-LD was 13 % and thus higher than that of CALD (9 %) and TALD (5 %). HCA-LD cases were reported from all states and included 77 different counties. Reporting counties represent the place of residence of the LD case-patients. German notification data show that cases of LD, and likely also HCALD, are underreported. Incidence rate and case fatality are highest in HCA-LD. HCA-LD occurs widespread. These results and the preventability of HCA-LD support the recommendation to thoroughly investigate single cases of HCA-LD in hospitals and nursing homes.

A revised version of the Bathing Water Directive 76/160/EWG has been elaborated to include scientific progress in risk assessment of bathing-related illness. The new Bathing Water Directive 2006/7/EC came into force on March 24, 2006, and will have to be implemented in the federal states within two years. The new bathing water directive contains several positive innovations which will improve a protection of the bathers namely i) health related indicators, ii) uniform detection methods, iii) requirements for active bathing water management, and iv) stricter standards for coastal waters. In Germany, the 16 federal states of the Federal Republic of Germany - the Länder - are responsible for monitoring bathing waters and for implementing the new bathing water directive into national law. A common master directive is being written by a joint working-group to ensure comparable implementation in all parts of Germany. An immediate application of the new directive is not possible since the parameter "intestinal enterococci" is currently not routinely monitored. It was decided to start monitoring according to the new directive in Germany in 2008. This will allow the first classification of bathing waters according to the new directive in 2011.

Drinking water analysis for Legionella from building installations is done quite frequently. Some questions arise from experience with this analysis. They will be discussed to allow uniform and comparable execution. Application of DIN EN ISO 19458 will lead to changes in the sampling procedure. This may make changes necessary even in current sampling and assessment programs. Concerning laboratory investigation, quality control of membrane filters and media turned out to be crucial. The assessment of quantitative results requires knowledge of the drinking water distribution system and of other facts that may be relevant for hygiene. Therefore, the assessment ought to be conducted by somebody with the respective knowledge.

The current regulatory approach in Germany combines regulations defined in the Drinking Water Ordinance with a comprehensive catalogue of technical rules as well as with guidelines and recommendations by the Federal Environment Agency and the Drinking Water Commission. This approach has proven successful in practice. Some parts would benefit from revision. The regulator is currently contemplating some revision in order to take experience of federal, state and local authorities as well as of water suppliers with implementation of the current Ordinance into account. The intention is improvement particularly towards reducing bureaucracy without compromising the current high level of public health protection through drinking water hygiene in Germany.

A set-up for experiments in the flow-through mode was constructed in order to test the efficacy of substances used for disinfecting water during drinking water treatment. A flow-through mode - in contrast to experiments under stationary conditions (so-called batch experiments) - was chosen, because this experimental design allows experiments to be carried out under constant conditions for an extended time (up to one week) and because efficacy testing is possible repeatedly, simultaneously and under exactly the same conditions for short (about 0.5 min) and also longer (about 47 min) contact times. With this experimental design the effect of biofilms along the inner pipe surfaces can be included in the observations. The construction of the experimental set-up is based on experience with laboratory flow-through systems that were installed by the UBA's drinking water department (formerly Institute for Water-, Soil- and Air Hygiene (WaBoLu) Institute) for testing disinfection with chlorine. In the first step, a test pipe for the simulation of a water works situation was installed. Water of different qualities can be mixed in large volumes beforehand so that the experimental procedure can be run with constant water quality for a minimum of one week. The kinetics of the disinfection reaction can be observed by extracting samples from eight sampling ports situated along the test pipe. In order to assign exact residence times to each of the sampling ports, tracer experiments were performed prior to testing disinfectant efficacy. This paper gives the technical details of the experimental set-up and presents the results of the tracer experiments to provide an introduction with respect to its potential.

In Germany the drinking water is to be monitored regularly. The sampling frequencies and the scale of monitoring of the water supplies are provided by the Drinking Water Ordinance 2001. Taking into account the overall samples taken, the drinking water quality ranges from good to very good, and the requirements for the microbiological, chemical and physical standards have been largely satisfied, as set out by the Drinking Water Ordinance 2001. What concerns most parameters, unremarkable variations have been measured in more than 99 % of samples taken. The highest frequency of non-compliance (in 1 to 2 % of samples taken) has been found in the parameters pesticides and coliform bacteria. Some impairments of drinking water quality could be traced to house installation systems, which do not meet the commonly accepted technical rules. In general, potential danger to human health does not exist. This information is based on the report by the Ministry of Health about the quality of drinking water in Germany in the period 2002-2004.

The new German Drinking Water Ordinance (TrinkwV 2001) demands that the requirements of water intended for human consumption be met up to the intrinsic tap, at which the water is used. This also applies to water supply systems for food trade aboard non-stationary facilities and in vehicles for commercial purposes. In contrast to stationary units for drinking water supply, the nonstationary units relocate and the responsibility changes with each public health authority agent. Therefore, a coordinated action between the federal states is desirable and necessary. The experience of the public health departments presents many non-compliant parameters of microbiology in water supply systems on markets and in vehicles. The development of practical and consistent recommendations for the surveillance of non-stationary units is required to give consistent standards to the users. The article gives a review about legal foundations and technical rules in order to define the drinking water supply systems on markets and in vehicles in compliance with the German Drinking Water Ordinance. Examples of laboratory results from different monitoring episodes from three federal states are shown.

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.

The new drinking water ordinance (TrinkwV 2001) entered into force in 2003. In this paper we report about experiences with monitoring microbiological quality of drinking water. Special problems, for instance requirements concerning the quality of raw water, new and "old" microbiological parameters, microbiological methods, assessment of parametric values, especially in the case of values higher than the imperative value, are also described. Possible developments in this field are discussed. The paper should support microbiological laboratories, public health officers and other public authorities in monitoring and assessment of drinking water quality.

Viruses in drinking water can cause infectious diseases. In the past, hepatitis A and E were the most frequently observed drinking- water-borne viral infections, but in recent years several small- and large-scale norovirus epidemics have been described, even in Europe. All virus species spread via drinking water are of fecal origin. They are regularly identified in waste water even after conventional multi-stage water treatment. The approved disinfection methods can cope with these viruses if they are not integrated in larger particles. For this reason particle separation is particularly important in water treatment. Virological tests are not reliable enough to ensure that drinking water is sufficiently virus-free. The examination of 100 mL of water for E. coli and coliform bacteria is not adequate proof either. If potentially contaminated raw water is used, consumer safety must be ensured by calculating the performance of water treatment plants on a case-by-case basis. Such a calculation takes into account the virus load of the raw water, the efficiency of the physical and chemical particle elimination steps and the effect of disinfection. Those factors which determine the effectiveness of disinfection, namely concentration and exposure time or UV radiation strength, must be adjusted according to the risk of viral infection, and calculated settings must be adhered to, even if favorable E. coli levels may make them seem excessive.

More than 30 laboratories routinely monitor water along southern California's beaches for bacterial indicators of fecal contamination. Data from these efforts frequently are combined and compared even though three different methods (membrane filtration (MF), multiple tube fermentation (MTF), and chromogenic substrate (CS) methods) are used. To assess data comparability and quantify variability within method and across laboratories, 26 laboratories participated in an intercalibration exercise. Each laboratory processed three replicates from eight ambient water samples employing the method or methods they routinely use for water quality monitoring. Verification analyses also were conducted on a subset of wells from the CS analysis to confirm or exclude the presence of the target organism. Enterococci results were generally comparable across methods. Confirmation revealed a 9% false positive rate and a 4% false negative rate in the CS method for enterococci, though these errors were small in the context of within- and among-laboratory variability. Fecal coliforms also were comparable across all methods, though CS underestimated the other methods by about 10%, probably because it measures only E. coli, rather than the larger fecal coliform group measured by MF and MTF. CS overestimated total coliforms relative to the other methods by several fold and was found to have a 40% false positive rate in verification. Across-laboratory variability was small relative to within- and among-method variability, but only after data entry errors were corrected. One fifth of the laboratories committed data entry errors that were much larger than any method-related errors. These errors are particularly significant because these data were submitted in a test situation where laboratories were aware they would be under increased scrutiny. Under normal circumstances, it is unlikely that these errors would have been detected and managers would have been obliged to issue beach water quality warnings.

Temperature measurements were taken at three pilot-scale facultative ponds located at Esholt wastewater treatment works in West Yorkshire, UK over two one-year periods. The measurements were taken at different depths using a technology called Thermochron iButton. The iButton readings were compared with temperature measurements taken by a YSI sonde probe and maximum/minimum thermometers: they were found to be within 1 .C. In the temperature range 3.18 .C the mean weekly and monthly air temperatures were found to be good predictors for the mean weekly and monthly pond water-column temperatures. The level of stratification in the ponds under UK climatic conditions was assessed; the data revealed that the ponds remained thermally stratified for significant periods during the year despite their shallow depth.

In an attempt to reduce the risk of infection in natural bathing waters the European Union is in the process of improving the Bathing Water Directive 76/160/EWG, which regulates the safety of such waters. The proposal contains several positive innovations which will improve the protection of the bathers: (1) health-related indicators, (2) harmonized detection methods, (3) requirements for active bathing water management, and (4) stricter standards for coastal waters. One of the most salient features of the current draft is the introduction of bacterial standards that are more stringent for coastal than for fresh waters. This decision on different standards seems unjustified: it was taken solely on the grounds that in two epidemiological studies-one carried out in coastal, the other in fresh waters-the maximum excess rate of gastroenteritis among bathers in coastal waters was higher than among bathers in fresh waters. However, it was not taken into account that the concentrations of bacterial indicators at which the gastroenteritis rate began to increase was nearly identical in both studies. The ratio between the standard concentrations of E. coli and intestinal enterococci in the draft was set at 2.5. This value does not correspond to the ratio found in German surface waters with low pollution levels, with ratios ranging from 2.7 to 4.0, and to the even higher ratios found in raw and treated sewage effluents. As a consequence in a majority of cases the non-compliance of bathing waters in Germany would be caused exclusively by a violation of E. coli standards. In assessing risks of infection it must also be taken into account that the adequacy of E. coli and intestinal enterococci for signaling the presence of viruses in water is far from optimal. The decay of viruses in water-estimated by the decay of bacteriophages-was found to be substantially slower than the die-off of indicator bacteria.

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.

The presence of Salmonella and its relationship with indicator organisms of fecal pollution, such as total coliforms, fecal coliforms and fecal streptococci, was studied at two marine zones in Portugal. Seventeen different Salmonella serotypes were isolated and identified, S. virchow was the most frequently isolated (21.6%). In addition, a high percentage (35.1%) was recorded for some Salmonella serotypes of clinical significance, namely S. enteritidis, S. infantis, S. typhimurium and S. virchow. In any of the samples from the two zones Salmonella was not detected in the absence of any of the indicator organisms. However, the incidence of Salmonella as a function of indicator concentration intervals established by the EEC standards was 0, 10 and 19.3% at guide values of total coliforms, fecal coliforms and fecal streptococci, respectively in the Faro samples (south of Portugal). In contrast, Salmonella incidence rates of 37.5, 36.4 and 33.3% were recorded at the corresponding guide values the Caminha samples (north of Portugal). No significant correlations (p>0.005) were obtained between Salmonella and the indicators at the sampling stations; however, total coliforms and fecal streptococci were the indicators most closely related to Salmonella in Caminha and Faro samples, respectively. Survival experiments in Escherichia coli, Enterococcus faecalis and S. typhimurium, using diffusion chambers, were performed to verify whether the lack of correlation between indicators and Salmonella was due to different inactivation rates in seawater. The results indicate that survival percentages of the three microorganisms tested were similar after 48 h of exposure to seawater.