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In Germany, recommendations on infection prevention and control of current virus outbreaks are given as communications by the Association for Applied Hygiene e.V. (VAH) together with the joint Disinfectant Commission of the German Association for the Control of Virus Diseases e.V. (DVV) and the Society of Virology* (GfV). The DVV was founded in 1954 in response to the ongoing threat to the population from polio and was given its current name in 1977. The DVV is supported by the Federal Ministry of Health, the Ministries of Health of the Federal States, scientific societies, as well as social foundations and organisations. Private individuals cannot be members of the DVV. The Society of Virology e.V. (GfV) is a scientific society for all virological fields in Germany, Austria and Switzerland, and is thus the largest virological society in Europe. With numerous commissions, guidelines and statements, it is the authoritative contact for research, healthcare and politics. The joint commission “Virus Disinfection” of these scientific societies focuses on the efficacy of chemical disinfection procedures against viruses. The VAH bundles the expertise of scientific societies and experts on infection prevention and is particularly committed to the quality assurance of hygiene measures. With the VAH disinfectant list, the association provides the standard reference for the selection of high-quality disinfection procedures. This disinfectant list has a tradition of more than 60 years in Germany. The original German version of this document was published in August 2022 and has now been made available to the international professional public in English. The document contains recommendations on hygiene and disinfection measures for monkeypox virus infections. Disinfectants against monkeypox must have at least proven efficacy against enveloped viruses (active against enveloped viruses); products with the efficacy ranges “limited virucidal activity” and “virucidal” can also be used. The disinfectant list of the VAH or the disinfectant list of the Robert Koch Institute are available for the selection of products. Especially in the case of contamination with crust or scab material, it should be noted that protein contamination can have a protective or stabilising effect on monkeypox. Therefore, cleaning – before disinfection – should always be carried out in this situation. Preventive measures such as vaccination and hygiene in the vicinity of people with monkeypox must be taken to prevent transmission to small children, pregnant women or people with a pronounced immune deficiency., In Deutschland geben der Verbund für angewandte Hygiene e.V. (VAH) zusammen mit der Kommission „Virusdesinfektion“ der Deutschen Vereinigung zur Bekämpfung der Viruskrankheiten e.V. (DVV) und der Gesellschaft für Virologie e.V. (GfV) Mitteilungen und Empfehlungen zu durch Viren übertragbare Krankheiten heraus. Der Schwerpunkt liegt dabei auf wirksamen Hygiene- und Desinfektionsmaßnahmen zur Prävention und Kontrolle bei gehäuftem Auftreten von Virusinfektionen. Die DVV wurde 1954 als Reaktion auf die andauernde Gefährdung der Bevölkerung durch die Poliomyelitis gegründet und erhielt 1977 ihren heutigen Namen. Die DVV wird vom Bundesministerium für Gesundheit, den Gesundheitsministerien der Bundesländer, wissenschaftlichen Fachgesellschaften sowie sozial engagierten Stiftungen und Organisationen getragen. Einzelpersonen können nicht Mitglied der DVV sein. Die Gesellschaft für Virologie e.V. (GfV) ist eine Fachgesellschaft für alle virologischen Fachgebiete in Deutschland, Österreich und der Schweiz und damit die größte virologische Fachgesellschaft in Europa. Mit zahlreichen Kommissionen, Leitlinien und Stellungnahmen ist sie zu virologischen Themen der maßgebende Ansprechpartner für Forschung, Gesundheitswesen und Politik. Die gemeinsame Kommission „Virusdesinfektion“ dieser Fachgesellschaften nimmt die Wirksamkeit chemischer Desinfektionsverfahren gegenüber Viren in den Fokus. Der VAH bündelt die Expertise von Fachgesellschaften und Fachleuten zur Infektionsprävention und setzt sich insbesondere für die Qualitätssicherung von Hygienemaßnahmen ein. Mit der Desinfektionsmittel-Liste des VAH gibt der Verbund die Standardreferenz zur Auswahl von qualitativ hochwertigen Desinfektionsverfahren heraus. Diese Desinfektionsmittel-Liste hat in Deutschland eine mehr als 60jährige Tradition. Die deutsche Originalfassung des vorliegenden Übersichtsartikels zur aktuellen Situation der Affenpocken wurde im August 2022 veröffentlicht und wird jetzt auf Englisch der internationalen Fachöffentlichkeit zur Verfügung gestellt. Der Artikel enthält Empfehlungen zu Hygiene- und Desinfektionsmaßnahmen bei Infektionen mit Affenpocken-Viren. Desinfektionsmittel gegen Affenpocken-Viren müssen mindestens eine nachgewiesene Wirksamkeit gegen behüllte Viren („begrenzt viruzid“) aufweisen; Produkte mit den Wirkbereichen „begrenzt viruzid PLUS“ und „viruzid“ können ebenfalls verwendet werden. Zur Auswahl von Produkten stehen die Desinfektionsmittel-Liste des VAH oder die Desinfektionsmittel-Liste des Robert Koch-Instituts zur Verfügung. Besonders bei Verunreinigungen mit Krusten- oder Schorfmaterial ist zu beachten, dass die Proteinbelastung eine schützende bzw. stabilisierende Wirkung auf Affenpocken haben kann. Daher ist hier stets eine gründliche Reinigung – vor der Desinfektion – durchzuführen. Durch Präventivmaßnahmen wie Impfungen und Hygieneverhalten gilt es, im Umfeld von an Affenpocken erkrankten Personen, Übertragungen auf Kleinkinder, Schwangere oder Personen mit einer ausgeprägten Immundefizienz zu verhindern.

When facing an emerging virus outbreak such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a quick reaction time is key to control the spread. It takes time to develop antivirals and vaccines, and implement vaccination campaigns. Therefore, preventive measures such as rapid isolation of cases and identification and early quarantine of cases’ close contacts—as well as masks, physical distancing, hand hygiene, surface disinfection and air control—are crucial to reduce the risk of transmission. In this context, disinfectants and antiseptics with proven efficacy against the outbreak virus should be used. However, biocidal formulations are quite complex and may include auxiliary substances such as surfactants or emollients in addition to active substances. In order to evaluate disinfectants’ efficacy objectively, meaningful efficacy data are needed. Therefore, the European Committee for Standardisation technical committee 216 ‘Chemical disinfectants and antiseptics’ Working Group 1 (medical area) has developed standards for efficacy testing. The European tiered approach grades the virucidal efficacy in three levels, with corresponding marker test viruses. In the case of SARS-CoV-2, disinfectants with proven activity against vaccinia virus, the marker virus for the European claim ‘active against enveloped viruses’, should be used to ensure effective hygiene procedures to control the pandemic.

International audience; Many studies emphasize the need for effective surface disinfection of the patient environment [1,2,3,4]. Thus, standardized tests for disinfectant evaluation under simulated practical conditions are of utmost importance to evaluate effective measures to prevent transmission of infectious agents from contaminated surfaces. Within the framework of CEN/TC 216, the 4-field test EN 16615 provides a phase 2/step 2 test simulating practical conditions to test microbicidal efficacy of surface disinfectants applied by wiping, i.e. with mechanical action [ 5]. Employing EN 16615, practical conditions of application are simulated. This includes contact time, temperature, organic soiling, and application of the disinfectant/wipe as well as pre-drying of specified test organisms on a test surface as carrier.

Washing machines should be further investigated as possible sites for horizontal gene transfer (ESBL genes) and cross-contamination with clinically important Gram-negative strains. Particularly in the health care sector, the knowledge of possible (re-)contamination of laundry (patients’ clothes and staff uniforms) with multidrug-resistant Gram-negative bacteria could help to prevent and to control nosocomial infections. This report describes an outbreak with a single strain of a multidrug-resistant bacterium (Klebsiella oxytoca sequence type 201) in a neonatal intensive care unit that was terminated only when the washing machine was removed. In addition, the study implies that changes in washing machine design and processing are required to prevent accumulation of residual water where microbial growth can occur and contaminate clothes., During the period from April 2012 to May 2013, 13 newborns (1 to 4 weeks of age) and 1 child in a pediatric hospital ward in Germany were colonized with Klebsiella oxytoca producing an extended-spectrum beta-lactamase (ESBL) (CTX-M-15). A microbiological source-tracking analysis with human and environmental samples was carried out to identify the source and transmission pathways of the K. oxytoca clone. In addition, different hygienic intervention methods were evaluated. K. oxytoca isolates were detected in the detergent drawer and on the rubber door seal of a domestic washer-extractor machine that was used in the same ward to wash laundry for the newborns, as well as in two sinks. These strains were typed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. The environmental findings were compared with those for the human strains and the isolates detected on clothing. The results from both techniques showed that the strains were identical (sequence type 201 and PFGE type 00531, a clone specific to this hospital and not previously isolated in Germany), emphasizing the washing machine as a reservoir and fomite for the transmission of these multidrug-resistant bacteria. After the washing machine was taken out of use, no further colonizations were detected during the subsequent 4-year period. IMPORTANCE Washing machines should be further investigated as possible sites for horizontal gene transfer (ESBL genes) and cross-contamination with clinically important Gram-negative strains. Particularly in the health care sector, the knowledge of possible (re-)contamination of laundry (patients’ clothes and staff uniforms) with multidrug-resistant Gram-negative bacteria could help to prevent and to control nosocomial infections. This report describes an outbreak with a single strain of a multidrug-resistant bacterium (Klebsiella oxytoca sequence type 201) in a neonatal intensive care unit that was terminated only when the washing machine was removed. In addition, the study implies that changes in washing machine design and processing are required to prevent accumulation of residual water where microbial growth can occur and contaminate clothes.

Summary Background Sporicidal surface disinfection is recommended to control transmission of Clostridium difficile in healthcare facilities. EN 17126 provides a method to determine the sporicidal activity in suspension and has been approved as a European standard. In addition, a sporicidal surface test has been proposed. Aim To determine the interlaboratory reproducibility of a test method for evaluating the susceptibility of a C. difficile spore preparation to a biocidal formulation following the 4-field test (EN 16615 methodology). Methods Nine laboratories participated. C. difficile NCTC 13366 spores were used. Glutaraldehyde (1% and 6%; 15 min) and peracetic acid (PAA; 0.01% and 0.04%; 15 min) were used to determine the spores' susceptibility in suspension in triplicate. Findings One-percent glutaraldehyde revealed a mean decimal log10 reduction of 1.03 with variable results in the nine laboratories (0.37–1.49) and a reproducibility of 0.38. The effect of 6% glutaraldehyde was stronger (mean: 2.05; range: 0.96–4.29; reproducibility: 0.86). PAA revealed similar results. An exemplary biocidal formulation based on 5% PAA was used at 0.5% (non-effective concentration) and 4% (effective concentration) to determine the sporicidal efficacy (4-field test) under clean conditions in triplicate with a contact time of 15 min. When used at 0.5% it demonstrated an overall log10 reduction of 2.68 (range: 2.35–3.57) and at 4% of 4.61 (range: 3.82–5.71). The residual contamination on the three primarily uncontaminated test fields was Conclusion The interlaboratory reproducibility seems to be robust.

For testing the effectiveness of air purification devices in regard to the reduction of virus-containing aerosols, a test method involving test viruses has been lacking until now. The use of bacteriophages (phiX174 phages) is a method to test the efficiency of air purification devices under experimental conditions. Using air purifiers with a HEPA filter H14, a 4.6-6.1 Log reduction of test viruses can be achieved if bacteriophages are directly aerosolised into the air purifier, which corresponds to a reduction of 99.9974-99.9999%. Due to the complexity and individuality of air flow, an experimental approach was used in which all outside influences were minimised. The experimental setup was practical and chosen to project a scenario of direct transmission by an emitting source to a recipient. The experiments were performed with and without the air purifier at a distance of 0.75 m and 1.5 m each. Using the air purifier at a setting of 1000 m3/h, the concentration of the phiX174 phages in the air could be reduced by 2.86 Log (mean value). Nevertheless, the experiments without the air purifier showed a similar reduction rate of 2.61 Log (mean value) after 35 min. The concentration of phiX174 phages in the air could be additionally reduced up to 1 log step (maximum value) by the use of the air purifier in comparison to the experiments without. Distance was shown to be an important factor for risk reduction.

The bactericidal activity of isopropanol was determined against Enterococcus faecium ATCC 6057, ST 796 (isopropanol-tolerant strain) and Enterococcus hirae ATCC 10541 (EN 13727). Isopropanol at 60% and 70% were effective (≥5.38 log10-reduction) in 15 s against all strains but 23% isopropanol was not (

International audience; J-Y. Maillard made a very important point in reflecting that, during efficacy testing of disinfectants, demonstration of neutralization of the biocidal effect at the end of contact time is crucial. We also agree that ‘It is thus puzzling and possibly concerning that products containing amines alone are being used as sporicides in healthcare settings

During the period from April 2012 to May 2013, 13 newborns and one child in a paediatric hospital ward in Germany were found to be colonised with a distinct clinical clone of an (extended spectrum β-lactamase) (ESBL)-producingKlebsiella oxytoca. This clone was specific to this hospital and had not been previously isolated in Germany.A source-tracking analysis was carried out to identify the source and transmission pathways of the ESBL-producingK. oxytocaclone. A systematic environmental survey of the ward and an audit of the procedures for cleaning and disinfecting surfaces, instruments, incubators, and washing machines was performed. Microbiological samples were obtained from environmental surfaces. Risk factors were analysed for epidemiological linkage.Isolates of an ESBL-producingK. oxytocawere found in the detergent drawer and on the rubber door seal of a washing machine and in two sinks. These strains were typed by pulsed-field-gel-electrophoresis (PFGE) and compared with the isolates from the newborns and their clothing and found to be identical. The retrospective analysis demonstrated that only newborns who had worn clothes that had been washed in the washing machine were colonised with the identical clone. After the washing machine was taken out of use, no further cases were detected over the following 4-year period.We conclude that washing machines are potential reservoirs and vectors for transmission ofEnterobacteriaceae, and likely other bacteria.ImportanceWashing machines should be further investigated as possible sites for horizontal gene transfer (ESBL-/carbapenemase-genes) and cross-contamination of clinically important Gram-negative strains. Particularly in the healthcare sector, the knowledge of possible (re-) contamination of laundry (patients clothes, staff uniforms) with multidrug-resistant Gram-negative bacteria could help to prevent and control nosocomial infections. To date, the potential of the washing machine as a source and vector of antibiotic-resistant gram-negative bacteria causing an outbreak in a clinical setting has not been investigated. This report shows that sampling of washing machines should be included in environmental audits associated with outbreak control management, and conditions for the laundering of baby 64 clothing should be reviewed.

Auf padiatrischen Stationen erfolgreiches Hygienemanagement zu betreiben ist eine anspruchsvolle und umfangreiche Aufgabe, nicht nur, weil die Patientengruppe auserst heterogen ist. Alle Menschen der Station mussen einbezogen werden – die Mitarbeiter aller Berufsgruppen ebenso wie die Patienten und deren Familien und Besucher. Der folgende Beitrag erlautert die Grundlagen zur Hygieneschulung und Patientenkommunikation in Kinderkliniken und gibt konkrete Beispiele, wie Hygienemanagement gelingen kann.

Microbial control is important to prevent nosocomial infections. Cold atmospheric plasma (CAP) is studied as an alternative disinfectant for dry surfaces. Bacterial endospores including Clostridium difficile and vegetative bacteria including Enterococcus faecium are treated on carriers, considering European testing standards. CAP reduces the spore load (106 cfu) by at least 3 log10 as required, independent from the bioburden (≤10 min treatments). Only a 2 log10 reduction is achieved with vegetative bacteria due to multilayer formation resulting from a higher required load (108 cfu). However, densities

Introduction Routine disinfection of frequently touched environmental surfaces and floors has been a controversial issue in hospital hygiene strategies. In view of the rise in multi-resistant micro-organisms and with more attention being paid to nosocomial infections and outbreaks occurring in community settings, environmental disinfection is being increasingly recognised as an important contribution to infection prevention. Discussion Environmental concerns regarding the use of chemical disinfectants and the lack of epidemiological data are frequently mentioned as an argument against routine disinfection. While the exact extent of the impact of contaminated surfaces on the rate of infections is difficult to establish, there is sufficient evidence for the possibility of cross-contamination from surfaces to patients and staff, and vice-versa, to make surface disinfection indispensable. Effective disinfection is dependent on risk assessment, on the use of products with tested efficacy, on suitable application methods and on the evaluation and monitoring of disinfection. The German Hospital Hygiene and Infection Prevention Commission (KRINKO) addresses these aspects in its very detailed recommendation ‘Hygiene Requirements on the Cleaning and Disinfection of Surfaces'. The German Association for Applied Hygiene (VAH) develops test methods and compiles a list of tested and certified disinfectant products to ensure product effectiveness. Public health authorities in Germany support the use of certified disinfectants. On a European level, much effort is put into the development of internationally acceptable practice-relevant test protocols for efficacy testing of disinfectants. Conclusion Surface disinfection should be viewed as part of a bundle of strategies in hospital hygiene. In order to ensure effective disinfection, the use of properly tested disinfectant products is essential. VAHaims to create a platform for tested disinfectants that is recognised European-wide. In addition, detailed recommendations on the prerequisites for effective surface disinfection processes, such as issued by KRIKNO, should be provided.

Detection of bacterial DNA from laboratory-prepared specimens such as water, urine, and blood has the potential to improve diagnostic tools in microbiology. A novel real-time PCR-based assay was developed and its performance and robustness were evaluated for a panel of spiked suspensions of 15 clinically relevant bacteria. As low as ten colony forming units (CFU)/100 μl were detectable. No cross-reactivity was observed, except for Staphylococcus aureus and Staphylococcus epidermidis. Nevertheless, S. aureus and S. epidermidis were reliably differentiated by melting curve analysis. The protocol was also validated with three groups containing a mixture of five spiked bacteria each, with the result of reliable differentiation. This novel assay allows an exact identification of 15 microbes relevant in intensive care medicine, including mixed infections, in a one run experiment in less than 4 h.

Numerous investigations have demonstrated efficiencies of different disinfection methods, but until now only little is known about long-term effects on community compositions of drinking water biofilms. Changes in the community structure, especially regrowth of hygienically relevant microorganisms could be critical for the drinking water quality. In this study the long-term effect of disinfection methods on biofilm communities in drinking water systems was analysed. Old drinking water biofilms grown in silicone tubes were exposed to different preparations of disinfectants (free chlorine, chlorine dioxide, hydrogen peroxide combined with fruit acid, silver and silver with peracetic acid, respectively) and subsequently further exposed in the original drinking water. The comparison of the treated and regrown biofilm populations with untreated ones by the DNA-fingerprinting method denaturing gradient gel electrophoresis (DGGE) revealed a considerable population shift caused by the disinfectants. The disinfection methods induced a selection pressure on the biofilm populations depending on the composition and concentrations. The similarities between the treated and untreated biofilms were generally low. Compared to preparations with peracetic acid the disinfection with hydrogen peroxide and silver resulted in higher similarities of the treated and untreated biofilms, but the microbial diversity increased. It can be concluded that the disinfectants have a major impact on the drinking water biofilm communities and that possibly the intervention selects persisters and microorganisms, which can live on the residuals of the dead biofilm cells. For the evaluation of the efficiency of disinfection methods in drinking water installations it is necessary not only to consider reduction of certain bacteria but also to pay attention to the biofilm community.

Previous investigations of biofilms, generated in a silicone tube model have shown that the number of colony forming units (CFU) can reach 10(7)/cm(2), the total cell count (TCC) of microorganisms can be up to 10(8)cells/cm(2). The present study focuses on the situation in in-building distribution systems. Different chemical disinfectants were tested for their efficacy on drinking water biofilms in silicone tubes: free chlorine (electrochemically activated), chlorine dioxide, hydrogen peroxide (H(2)O(2)), silver, and fruit acids. With regard to the widely differing manufacturers' instructions for the usage of their disinfectants three different variations of the silicone tube model were developed to simulate practical use conditions. First the continuous treatment, second the intermittent treatment, third the efficacy of external disinfection treatment and the monitoring for possible biofilm formation with the Hygiene-Monitor. The working experience showed that it is important to know how to handle the individual disinfectants. Every active ingredient has its own optimal application concerning its concentration, exposure time, physical parameters like pH, temperature or redox potential. When used correctly all products tested were able to reduce the CFU to a value below the detection limit. Most of the active ingredients could not significantly reduce the TCC/cm(2), which means that viable microorganisms may still be present in the system. Thus the question arises what happened with these cells? In some cases SEM pictures of the biofilm matrix after a successful disinfection still showed biofilm residues. According to these results, no general correlation between CFU/cm(2), TCC/cm(2) and the visualised biofilm matrix on the silicone tube surface (SEM) could be demonstrated after a treatment with disinfectants.

In den letzten Jahrzehnten spielten Infektionsrisiken auserhalb medizinischer Einrichtungen in der offentlichen Risikowahrnehmung nur eine geringe Rolle. Dies trifft insbesondere fur den hauslichen Bereich zu. Jedoch haben sich in diesem Zeitraum erhebliche soziodemographische, gesundheitspolitische und technologische Veranderungen vollzogen. So werden in Deutschland immer mehr pflegebedurftige Menschen im Familienhaushalt versorgt. Derzeit liegt diese Zahl bei ca. 1,4 Millionen. Zudem hat die epidemiologische Bedeutung relevanter Krankheitserreger, wie zum Beispiel von Campylobacter oder Noroviren, erheblich zugenommen. Diese Entwicklungen er fordern eine Neubewertung der Infektionsrisiken auserhalb medizinischer Einrichtungen und einen Konsens uber notwendige Hygienestrategien. Auf diese Aspekte soll im vorliegenden Beitrag ausfuhrlich eingegangen werden.

Basic hygiene measures aim at promoting and maintaining good health. The necessary routines are most effectively learned and adopted during childhood. These key findings form the basis for the educational programme "Hygiene Tips for Kids" which was initiated at the Department of Hygiene and Public Health at Bonn University under the auspices of WHO Europe in 2003. The programme addresses children, teachers and parents and offers a range of materials and activities tailored to the specific needs of the target groups based on expert advice. The objective is to exert a long-lasting, positive influence on the performance of hygiene routines. Campaigns are usually directed at pre-school, kindergarten and primary school settings, with the public health service personnel playing a crucial role in coordinating and implementing the various activities. Evaluation of a campaign in the federal state of Mecklenburg-Vorpommern has proven a positive effect on hand washing routines in pre-school as well as in the domestic setting. Moreover, Hygiene Tips for Kids has a sustained positive effect on the cooperation and communication between public health authorities and teachers, children and their parents. Teachers implement their own ideas within a framework of standardised information to suit their local needs. A long-term goal would be the obligatory integration of a sensible health education programme in the syllabus of pre-school, kindergarten and primary schools.

Recently, new insights into the persistence of pathogens, their transfer from inanimate surfaces to humans and the risk of contamination and dissemination of pathogens by detergents have been gained. Furthermore, new experimental data on the interruption of chains of infection by disinfectants as well as results of outbreak-control studies are now available. Hence it has become necessary to reassess the potential benefits using disinfectants to prevent and control nosocomial infections. Based on the new findings and in view of the increasing incidence of nosocomial infections and antibiotic resistances, the German Robert-Koch-Institut has issued completely revised recommendations on Household Cleaning and Surface Disinfection. With respect to these recommendations we developed a new test method, which allows comparison of the efficacy of disinfection in reducing the microbial loads and their dissemination with that of cleaning procedures under practical conditions. In a multi-factor approach, mechanical properties (wet mop technique), utensils (different mop materials) and active agents (disinfectant, detergent) were taken into consideration. We found that under the given conditions, dissemination of the test organism Staphylococcus aureus did not take place when using aldehydes and peroxides, it did take place, however, when water, surfactants, and the disinfectants glycol derivatives, quaternary ammonium compounds and alkylamines were used.

Hygienic and microbiological examinations of watercourses are usually not carried out during heavy rainfall and runoff events. After rainfall or snowmelt, there are often massive increases in turbidity in flooding creeks in mountain ranges, which are frequently interpreted as an indication of microbial contamination. The aim of this study was to quantify the microbial loads of watercourses during such runoff events and to compare these loads with loads occurring during regular conditions. In a 14-month monitoring period we investigated the microbial loads of three tributaries of different drinking water reservoirs. A total of 99 water samples were taken under different runoff conditions and analyzed to determine physical, chemical, bacterial, and parasitic parameters. Thirty-two water samples were considered event samples during nine measuring series. The criteria for events, based on duration and intensity of precipitation, water depth gauge measurements, and dynamics, had been fixed before the investigation for each creek individually. Of the physical and chemical parameters examined, only the turbidity, pH, and nitrate values differed clearly from the values obtained for regular samples. Most of the bacteriological parameters investigated (colony, Escherichia coli , coliform, fecal streptococcal, and Clostridium perfringens counts) increased considerably during extreme runoff events. If relevant sources of parasitic contamination occurred in catchment areas, the concentrations of Giardia and Cryptosporidium rose significantly during events. The results show that substantial shares of the total microbial loads in watercourses and in drinking water reservoirs result from rainfall and extreme runoff events. Consequently, regular samples are considered inadequate for representing the microbial contamination of watercourse systems. The procedures for raw water surveillance in the context of multiple-barrier protection and risk assessment ought to include sampling during extreme runoff situations.

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.

Currently the IWW-Rheinisch-Westfaelisches Institut fuer Wasserforschung gemeinnuetzige GmbH, an Institute at the University of Duisburg, the Institute of Hygiene of the University of Bonn and the Wasserwerk des Kreises Aachen (WdKA) are realising a project supported by the German Federal Ministry for Education, Science, Research and Technology (BMBF). This project is to investigate whether membrane filtration (micro-or ultrafiltration) is able to enhance the particle removal efficiency of an existing drinking water treatment plant. The first step of the total investigation programme was to operate three different pilot plants in parallel with a capacity of about 10 m3/h each. This paper presents results concerning the pilot plant investigations.

We evaluated the capability of a commercially available hand-held device that emits ultraviolet (UV) light to disinfect plain surfaces. Eight bacterial species were tested, including Clostridium difficile ribotype 027 and 3 other spore-forming species. Even bacterial spores could be successfully inactivated within a few seconds of irradiation. UV light may provide an alternative for the decontamination of medical products, such as mobile phones or tablet computers, that cannot be treated otherwise.

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.

Helicobacter pylori is a cause of peptic ulcer disease and a causative agent of gastric cancer. Currently, a possible waterborne route of transmission or a possible survival in drinking water biofilms is discussed. H. pylori, like many other bacterial strains, has the ability to enter the viable but nonculturable state (vbnc) in case of unfavorable conditions. Therefore it is necessary to develop new analysis tools for vbnc bacteria. We established a fast and reliable method to detect H. pylori in drinking water biofilms by quantitative real-time PCR which makes it redundant to use difficult cultivation methods for nonculturable bacteria. With this method it was possible to identify water biofilms as a niche for H. pylori. The real-time PCR analysis targets the ureA subunit of the Helicobacter pylori urea gene which showed high specificity and sensitivity. The quantitative real-time PCR was used to detect H. pylori in biofilms of different age, unspiked and spiked with predetermined levels of cells. The drinking water biofilms were generated in a silicone-tube model. The DNA-sequences for probe and primers showed no cross-homologies to other related bacteria and it was possible to detect less than 10 genomic units of H. pylori. This novel method is a useful tool for a fast screening of drinking water biofilms for H. pylori. The results suggest that drinking water biofilms may act as a reservoir for H. pylori which raises new concerns about the role of biofilms as vectors for pathogens like Helicobacter pylori.

Aktuelle epidemiologische und hygienisch-mikrobiologische Untersuchungen zeigen, dass dem Hausinstallationssystem in medizinischen Einrichtungen als Infektionsreservoir fur nosokomiale Infektionen eine bislang erheblich unterschatzte Bedeutung zukommt. Nach Einfuhrung spezifischer Praventionsmasnahmen konnte das Risiko einer Ubertragung relevanter nosokomialer Infektionserreger wie Legionellen und Pseudomonaden deutlich reduziert werden. Im vorliegenden Beitrag werden Besonderheiten der Wasseranwendung in medizinischen Einrichtungen, die besondere Vulnerabilitat bestimmter Patienten, die wichtigsten wasserassoziierten Erreger und deren okologische Besonderheiten, rechtliche Aspekte und die wichtigsten Masnahmen zur Pravention und Kontrolle behandelt.

The virion of a poxvirus is an enveloped particle that differs significantly from other enveloped viruses. Apart from DNA, proteins and phospholipids, poxvirus virions also contain carbohydrates. They show a high environmental stability and remain contagious over a period of several months in an ambient environment. Poxviruses show an extraordinary high resistance to drying, which is further enhanced by materials in which they are released into the environment (e.g., dermal crusts, serum, blood residues and other excretions). Dried Vaccinia virus can be stored at 4°C over a period of more than 35 weeks without any loss of infectivity. Frozen in buffer at -20°C, a titer reduction of only 3 log-steps is observed within 15 years. In general, virus isolated from patients and/or environment is more resistant to environmental conditions than virus deriving from cell cultures. In addition, poxviruses show a high stability towards different pH values. Due to their low lipid content, they are less sensitive to organic solvents/disinfectants compared to other enveloped viruses. This is the reason for the considerably higher resistance of poxviruses to diethylether in comparison to other enveloped viruses. Despite all of these aspects, poxviruses are highly sensitive to all common approved disinfection regimens. Cell-bound poxvirus may show a higher stability than cell-free virus. This phenomenon is not observed if quaternary ammonium compounds are used. Due to the possible renewed importance of smallpox, e.g., in case of abuse in biological warfare, but also because of the impact of poxviruses in veterinary medicine, representatives of the poxvirus family have been chosen to test the efficacy of common disinfectants. The common sterilization procedures - thermal, chemical, an/or radiation - are usually effective against poxviruses.

A method based on measuring a soil-induced fluorescence intensity response of 1,8-anilinonaphthalene sulfonate at two fixed wavelengths (460 and 510 nm) was used for determining residual contamination on test soil carriers simulating medical devices after passage through a hospital washer-disinfector. The fluorescence response can be satisfactorily calibrated to soil levels as low as approximately 1 microg/L. Practical tests were performed in two hospitals with washer-disinfectors of 3 types and with several chemical or enzymic cleansers-disinfectants. In combination with the previously developed system of standardized test soil carriers simulating both easily and poorly accessible parts of soiled medical devices, the liver-lactose-oil test soil and an efficient sonication procedure for stripping the residual soil off the carriers, this soil detection method permits the detection of very low contamination levels.

We introduce a consensus real-time PCR protocol for the detection of bacterial DNA from laboratory-prepared specimens such as water, urine, and plasma. This prototype detection system enables an exact Gram stain classification and, in particular, screening for specific species of 17 intensive care unit-relevant bacteria by means of fluorescence hybridization probes and melting-curve analysis in a one-run experiment. One strain of every species was tested at a final density of 10 6 CFU/ml. All bacteria examined except Staphylococcus aureus and Staphylococcus epidermidis could be differentiated successfully; S. aureus and S. epidermidis could only be classified as “ Staphylococcus species.” The hands-on time for preparation of the DNA, performance of the PCR, and evaluation of the PCR results was less than 4 h. Nevertheless, this prototype detection system requires more clinical validation.

An easy-to construct, easy-to-operate standardized system was developed for determining the residual biological contamination of surgical instruments, endoscopes and other medical appliances subjected to hospital cleansing and/or disinfection. It consists of standard-sized pieces of glass, metal or endoscope plastic — dirt carriers — either bare or enclosed in truncated Eppendorf caps to simulate hard-to-access conditions. The surface of the carriers is covered with model dirt simulating biological contamination and the carriers are then affixed to sturdy metal holders. Conventional model dirts were found to peel or flake off the carrier surface, lowering the precision of residual soil determination. A newly developed model dirt consisting of liver mash, lactose and sunflower oil and exhibiting low tendency to peel off surfaces was therefore used. The whole setup was subjected to chemical or enzymic cleansing programs at elevated temperature in hospital washer-disinfectors of two types, and the residual dirt after cleansing was determined by three methods. The method using toxicant-doped dirt that quenches the luminescence of an indicator bacteriumPhotobacterium phosphoreum gave satisfactory data under laboratory conditions but with hospital-washed samples it exhibited excessive fluctuations caused by bacterium-dirt interactions and by physical influences. Both other methods gave better results but displayed some process sensitivity. The luciferin-luciferase-based ATP bioluminescence assay sometimes gave low or even negative dirt level values and showed a low effect of reduced dirt accessibility on cleansing of metal carriers. The Bradford protein assay showed about equal cleansing efficiency for both easily and poorly accessible carriers after enzymic cleansing. Our system can be used for determining low levels of residual contamination of medical appliances after cleansing/disinfection and assessing the efficiency of commercial washer-disinfectors; its efficiency can be further increased by using a cleansing process-insensitive method for soil detection and quantification.

Kinetic features (initial start-up phase, drug pumping velocity and efficiency as dependent on drug concentration and growth phase) of yeast plasma membrane multidrug resistance ABC pumps were studied by monitoring the uptake of the fluorescent potentiometric dye diS-C3(3), which has been found to be expelled from the cells by these pumps. The monitoring was done with Saccharomyces cerevisiae mutants AD1-8 and AD1-3 deleted in different ABC pumps, and in their pump-competent parent strain US50-18C overexpressing transcriptional activators Pdr1p and Pdr3p. On addition to the cells, diS-C3(3) is expelled by the Pdr5p, Yor1p and Snq2p pumps with overlapping substrate specificity. The pump action can be assessed as a difference between the dye uptake curve for pump-competent and pump-deleted cells. The pump-mediated dye efflux, which shows an initial lag of various lengths, maintains a certain residual intracellular dye level. In the absence of external glucose the dye efflux ability of the pumps depends on the growth phase; late exponential and stationary cells can maintain the export for tens of minutes, whereas exponential cells keep up the pump action for limited time periods. This may reflect an insufficient number of pump molecules in the membrane or an effect of insufficient pump energization from endogenous sources. This effect is not mediated by changes in membrane potential because lowered membrane potential caused by inhibition of the plasma membrane H+-ATPase does not affect the pump action.