AWMF mold guideline "Medical clinical diagnostics for indoor mold exposure" - Update 2023 AWMF Register No. 161/001

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[Measures and Recommendations for Ensuring Adequate Inpatient Care Capacities for Pandemic Management within a Region: Results of a Hybrid Delphi Method]

INTRODUCTION

Since the beginning of the pandemic in spring 2020, inpatient healthcare has been under enormous burden, which is reflected especially in overworked staff, imprecise bed planning and/or data transfer. According to the recommendation of the Science Council, university clinics should play a controlling role in regional healthcare and act in conjunction with surrounding hospitals and practices.

METHODS

In September 2021, 31 representatives from 18 university hospitals were invited to a hybrid Delphi study with a total of 4 survey rounds to discuss criteria for effective inpatient care in a pandemic situation, which were extracted from previous expert interviews. Criteria that were classified as very important/relevant by≥75% of the participants in the first round of the survey (consensus definition) were then further summarized in 4 different small groups. In a third Delphi round, all participants came together again to discuss the results of the small group discussions. Subsequently, these were prioritized as Optional ("can"), Desirable ("should") or Necessary ("must") recommendations.

RESULTS

Of the invited clinical experts, 21 (67.7%) participated in at least one Delphi round. In an online survey (1st Delphi round), 233 criteria were agreed upon and reduced to 84 criteria for future pandemic management in four thematic small group discussions (2nd Delphi round) and divided into the small groups as follows: "Crisis Management and Crisis Plans" (n=20), "Human Resources Management and Internal Communication" (n=16), "Regional Integration and External Communication" (n=24) and "Capacity Management and Case & Care" (n=24). In the following group discussion (3rd Delphi round), the criteria were further modified and agreed upon by the experts, so that in the end result, there were 23 essential requirements and recommendations for effective inpatient care in a pandemic situation.

CONCLUSION

The results draw attention to key demands of clinical representatives, for example, comprehensive digitization, standardization of processes and better (supra) regional networking in order to be able to guarantee needs-based care even under pandemic conditions. The present consensus recommendations can serve as guidelines for future pandemic management in the inpatient care sector.

Environmental Contamination and Persistence of Clostridioides difficile in Hospital Wastewater Systems

Clostridioides difficile produces an environmentally resistant dormant spore morphotype that infected patients shed to the hospital environment. C. difficile spores persist in clinical reservoirs that are not targeted by hospital routine cleaning protocols. Transmissions and infections from these reservoirs present a hazard to patient safety. This study aimed to assess the impact of patients acutely suffering from C. difficile-associated diarrhea (CDAD) on C. difficile environmental contamination to identify potential reservoirs. Twenty-three hospital rooms accommodating CDAD inpatients with corresponding soiled workrooms of 14 different wards were studied in a German maximum-care hospital. Additionally, four rooms that never accommodated CDAD patients were examined as negative controls. Stagnant water and biofilms from sinks, toilets, and washer disinfector (WD) traps as well as swabs from cleaned bedpans and high-touch surfaces (HTSs) were sampled. For detection, a culture method was used with selective medium. A latex agglutination assay and a Tox A/B enzyme-linked immunosorbent assay were performed with suspect colonies. Stagnant water and biofilms in hospital traps (29%), WDs (34%), and HTSs (37%) were found to be reservoirs for large amounts of C. difficile during the stay of CDAD inpatients that decreased but could persist 13 ± 6 days after their discharge (13%, 14%, and 9.5%, respectively). Control rooms showed none or only slight contamination restricted to WDs. A short-term cleaning strategy was implemented that reduced C. difficile in stagnant water almost entirely. IMPORTANCE Wastewater pipes are microbial ecosystems. The potential risk of infection emanating from the wastewater for individuals is often neglected, since it is perceived to remain in the pipes. However, sewage systems start with siphons and are thus naturally connected to the outside world. Wastewater pathogens do not only flow unidirectionally to wastewater treatment plants but also retrogradely, e.g., through splashing water from siphons to the hospital environment. This study focused on the pathogen C. difficile, which can cause severe and sometimes fatal diarrheas. This study shows how patients suffering from such diarrheas contaminate the hospital environment with C. difficile and that contamination persists in siphon habitats after patient discharge. This might pose a health risk for hospitalized patients afterward. Since this pathogen's spore morphotype is very environmentally resistant and difficult to disinfect, we show a cleaning measure that can almost entirely eliminate C. difficile from siphons.

Hospital sanitary facilities on wards with high antibiotic exposure play an important role in maintaining a reservoir of resistant pathogens, even over many years

BACKGROUND

Hospitals with their high antimicrobial selection pressure represent the presumably most important reservoir of multidrug-resistant human pathogens. Antibiotics administered in the course of treatment are excreted and discharged into the wastewater system. Not only in patients, but also in the sewers, antimicrobial substances exert selection pressure on existing bacteria and promote the emergence and dissemination of multidrug-resistant clones. In previous studies, two main clusters were identified in all sections of the hospital wastewater network that was investigated, one K. pneumoniae ST147 cluster encoding NDM- and OXA-48 carbapenemases and one VIM-encoding P. aeruginosa ST823 cluster. In the current study, we investigated if NDM- and OXA-48-encoding K. pneumoniae and VIM-encoding P. aeruginosa isolates recovered between 2014 and 2021 from oncological patients belonged to those same clusters.

METHODS

The 32 isolates were re-cultured, whole-genome sequenced, phenotypically tested for their antimicrobial susceptibility, and analyzed for clonality and resistance genes in silico.

RESULTS

Among these strains, 25 belonged to the two clusters that had been predominant in the wastewater, while two others belonged to a sequence-type less prominently detected in the drains of the patient rooms.

CONCLUSION

Patients constantly exposed to antibiotics can, in interaction with their persistently antibiotic-exposed sanitary facilities, form a niche that might be supportive for the emergence, the development, the dissemination, and the maintenance of certain nosocomial pathogen populations in the hospital, due to antibiotic-induced selection pressure. Technical and infection control solutions might help preventing transmission of microorganisms from the wastewater system to the patient and vice versa, particularly concerning the shower and toilet drainage. However, a major driving force might also be antibiotic induced selection pressure and parallel antimicrobial stewardship efforts could be essential.

Examining Different Analysis Protocols Targeting Hospital Sanitary Facility Microbiomes

Indoor spaces exhibit microbial compositions that are distinctly dissimilar from one another and from outdoor spaces. Unique in this regard, and a topic that has only recently come into focus, is the microbiome of hospitals. While the benefits of knowing exactly which microorganisms propagate how and where in hospitals are undoubtedly beneficial for preventing hospital-acquired infections, there are, to date, no standardized procedures on how to best study the hospital microbiome. Our study aimed to investigate the microbiome of hospital sanitary facilities, outlining the extent to which hospital microbiome analyses differ according to sample-preparation protocol. For this purpose, fifty samples were collected from two separate hospitals-from three wards and one hospital laboratory-using two different storage media from which DNA was extracted using two different extraction kits and sequenced with two different primer pairs (V1-V2 and V3-V4). There were no observable differences between the sample-preservation media, small differences in detected taxa between the DNA extraction kits (mainly concerning Propionibacteriaceae), and large differences in detected taxa between the two primer pairs V1-V2 and V3-V4. This analysis also showed that microbial occurrences and compositions can vary greatly from toilets to sinks to showers and across wards and hospitals. In surgical wards, patient toilets appeared to be characterized by lower species richness and diversity than staff toilets. Which sampling sites are the best for which assessments should be analyzed in more depth. The fact that the sample processing methods we investigated (apart from the choice of primers) seem to have changed the results only slightly suggests that comparing hospital microbiome studies is a realistic option. The observed differences in species richness and diversity between patient and staff toilets should be further investigated, as these, if confirmed, could be a result of excreted antimicrobials.

SARS-CoV-2 in Environmental Samples of Quarantined Households

The role of environmental transmission of SARS-CoV-2 remains unclear. Thus, the aim of this study was to investigate whether viral contamination of air, wastewater, and surfaces in quarantined households result in a higher risk for exposed persons. For this study, a source population of 21 households under quarantine conditions with at least one person who tested positive for SARS-CoV-2 RNA were randomly selected from a community in North Rhine-Westphalia in March 2020. All individuals living in these households participated in this study and provided throat swabs for analysis. Air and wastewater samples and surface swabs were obtained from each household and analysed using qRT-PCR. Positive swabs were further cultured to analyse for viral infectivity. Out of all the 43 tested adults, 26 (60.47%) tested positive using qRT-PCR. All 15 air samples were qRT-PCR-negative. In total, 10 out of 66 wastewater samples were positive for SARS-CoV-2 (15.15%) and 4 out of 119 surface samples (3.36%). No statistically significant correlation between qRT-PCR-positive environmental samples and the extent of the spread of infection between household members was observed. No infectious virus could be propagated under cell culture conditions. Taken together, our study demonstrates a low likelihood of transmission via surfaces. However, to definitively assess the importance of hygienic behavioural measures in the reduction of SARS-CoV-2 transmission, larger studies should be designed to determine the proportionate contribution of smear vs. droplet transmission.

SARS-CoV-2 in Environmental Samples of Quarantined Households

The role of environmental transmission of SARS-CoV-2 remains unclear. Thus, the aim of this study was to investigate whether viral contamination of air, wastewater, and surfaces in quarantined households result in a higher risk for exposed persons. For this study, a source population of 21 households under quarantine conditions with at least one person who tested positive for SARS-CoV-2 RNA were randomly selected from a community in North Rhine-Westphalia in March 2020. All individuals living in these households participated in this study and provided throat swabs for analysis. Air and wastewater samples and surface swabs were obtained from each household and analysed using qRT-PCR. Positive swabs were further cultured to analyse for viral infectivity. Out of all the 43 tested adults, 26 (60.47%) tested positive using qRT-PCR. All 15 air samples were qRT-PCR-negative. In total, 10 out of 66 wastewater samples were positive for SARS-CoV-2 (15.15%) and 4 out of 119 surface samples (3.36%). No statistically significant correlation between qRT-PCR-positive environmental samples and the extent of the spread of infection between household members was observed. No infectious virus could be propagated under cell culture conditions. Taken together, our study demonstrates a low likelihood of transmission via surfaces. However, to definitively assess the importance of hygienic behavioural measures in the reduction of SARS-CoV-2 transmission, larger studies should be designed to determine the proportionate contribution of smear vs. droplet transmission.

Air filtration as a tool for the reduction of viral aerosols

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.

Low-threshold SARS-CoV-2 testing facility for hospital staff: Prevention of COVID-19 outbreaks?

BACKGROUND

The ongoing global SARS-CoV-2 pandemic has caused over 4.7 million infections greatly challenging healthcare workers (HCW) and medical institutions worldwide. The SARS-CoV-2 pandemic has shown to significantly impact mental and physical health of HCW. Thus, implementation of testing facilities supporting HCW are urgently needed.

METHODS

A low-threshold SARS-CoV-2 testing facility was introduced at the University Hospital Bonn, Germany, in March 2020. Irrespective of clinical symptoms employees were offered a voluntary and free SARS-CoV-2 test. Furthermore, employees returning from SARS-CoV-2 risk regions and employees after risk contact with SARS-CoV-2 infected patients or employees were tested for SARS-CoV-2 infection. Pharyngeal swabs were taken and reverse transcription polymerase chain reaction for detection of SARS-CoV-2 was performed, test results being available within 24 h. Profession, symptoms and reason for SARS-CoV-2 testing of employees were recorded.

RESULTS

Between 9th March and April 30, 2020, a total of 1510 employees were tested for SARS-CoV-2 infection. 1185 employees took advantage of the low-threshold testing facility. One percent (n = 11) were tested positive for SARS-CoV-2 infection, 18% being asymptomatic, 36% showing mild and 36% moderate/severe symptoms (missing 10%). Furthermore, of 56 employees returning from SARS-CoV-2 risk regions, 18% (10/56) were tested SARS-CoV-2 positive. After risk contact tracking by the hospital hygiene 6 patient-to-employee transmissions were identified in 163 employees with contact to 55 SARS-CoV-2 positive patients.

CONCLUSION

In the absence of easily accessible public SARS-CoV-2 testing facilities low-threshold SARS-CoV-2 testing facilities in hospitals with rapid testing resources help to identify SARS-CoV-2 infected employees with absent or mild symptoms, thus stopping the spread of infection in vulnerable hospital environments. High levels of professional infection prevention training and implementation of specialized wards as well as a perfectly working hospital hygiene network identifying and tracking risk contacts are of great importance in a pandemic setting.

Recurrent mucocutaneous infections caused by PVL-positive Staphylococcus aureus strains: a challenge in clinical practice

BACKGROUND

Recurrent mucocutaneous infections caused by PVL-positive Staphylococcus (S.) aureus strains represent an increasing problem in Germany. Although there have been several outbreaks at day care centers and in urban communities in recent years, there are currently no diagnostic algorithms or treatment recommendations for these particular infections in Germany.

METHODS

We performed a literature search in the PubMed/MEDLINE database with the goal of developing an algorithm for diagnosis and treatment of these infections. National and international recommendations were also considered.

RESULTS

Panton-Valentine leukocidin (PVL) is a pore-forming protein produced by certain S. aureus strains. Both methicillin-susceptible (MSSA) and methicillin-resistant S. aureus (MRSA) strains may carry the lukS-lukF gene responsible for PVL production. The clinical presentation of infections caused by PVL-positive S. aureus ranges from isolated recurrent abscesses to extensive furunculosis. Despite adequate treatment of primary infections, approximately 40 % of patients develop recurrent disease. The choice of treatment regimen is guided by the clinical presentation of the infection. In addition, some scientific literature recommends bacteriological screening of patients and their contacts, followed by decolonization of affected individuals.

CONCLUSIONS

The present article focuses on the pathogenesis and risk factors of recurrent mucocutaneous infections caused by PVL-positive S. aureus strains and proposes a diagnostic and therapeutic algorithm for optimal patient care.

Questionnaire based evaluation of the motivation of surgically treated patients to participate in preventative hygiene measures

Background: Nosocomial infections caused by antibiotic-resistant pathogens demonstrate the continued need for preventive hygiene management strategies. Information and training of patients in their personal hygiene is a current requirement of the German Society for Hospital Hygiene, and is recommended by the Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention beim Robert-Koch Institut, KRINKO) at the Robert Koch Institute.

Aim: The aim of this study was to evaluate patients’ existing knowledge of hygiene and their motivation to actively participate in preventive hygiene measures.

Methods: This study included 445 inpatients at the Polyclinic for Surgery of University Hospital Bonn. Subjects were interviewed over a 6-month period using a questionnaire comprising 21 questions on the topic of hygiene.

Results: The majority of patients rated their subjective level of knowledge as intermediate (41%), 25% as poor and 35% as high. The respondents rated the active inclusion of patients in hygiene practices as highly relevant, and were willing to actively contribute to infection prevention, whereby the patients considered hand washing and hand disinfection in particular as important starting points. 78% of the respondents wanted more information on hygiene, particularly on wound and food hygiene. Targeted hygiene education provided by hospital staff had a positive effect on the patients’ subjective level of information, as well as on their confidence in physicians and nursing staff. Previous information via television or radio had a negative impact on the patients’ subjective information level and on their confidence in hospital staff.

Conclusion: Most surgically treated patients are motivated to actively contribute to preventive hygiene measures. This represents an additional and important option for applying hospital hygiene more effectively and, above all, closer to the patient. Information and education should preferably be performed by healthcare professionals.

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

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

Antibiotic resistant bacteria and resistance genes in biofilms in clinical wastewater networks

Increasing isolation rates of resistant bacteria in the last years require identification of potential infection reservoirs in healthcare facilities. Especially the clinical wastewater network represents a potential source of antibiotic resistant bacteria. In this work, the siphons of the sanitary installations from 18 hospital rooms of two German hospitals were examined for antibiotic resistant bacteria and antibiotic residues including siphons of showers and washbasins and toilets in sanitary units of psychosomatic, haemato-oncological, and rehabilitation wards. In addition, in seven rooms of the haemato-oncological ward, the effect of 24 h of stagnation on the antibiotic concentrations and MDR (multi-drug-resistant) bacteria in biofilms was evaluated. Whereas no antibiotic residues were found in the psychosomatic ward, potential selective concentrations of piperacillin, meropenem and ciprofloxacin were detected at a rehabilitation ward and ciprofloxacin and trimethoprim were present at a haemato-oncology ward. Antibiotic resistant bacteria were isolated from the siphons of all wards, however in the psychosomatic ward, only one MDR strain with resistance to piperacillin, third generation cephalosporins and quinolones (3MRGN) was detected. In contrast, the other two wards yielded 11 carbapenemase producing MDR isolates and 15 3MRGN strains. The isolates from the haemato-oncological ward belonged mostly to two specific rare sequence types (ST) (P. aeruginosa ST823 and Enterobacter cloacae complex ST167). In conclusion, clinical wastewater systems represent a reservoir for multi-drug-resistant bacteria. Consequently, preventive and intervention measures should not start at the wastewater treatment in the treatment plant, but already in the immediate surroundings of the patient, in order to minimize the infection potential.

The occurrence of antimicrobial substances in toilet, sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference. To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02 μg·L^-1 to a maximum of 79 mg·L^-1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.

Rationaler Antibiotikaeinsatz Daten aus dem mre-netz regio rhein-ahr aus einer Umfrage von 2014 und Vergleich mit bundesweiten Daten von 2009

Einführung Die Bedeutung von multiresistenten gramnegativen Erregern als Ursache von lebensbedrohlichen Infektionen lässt dem Antibiotic Stewardship höchste Bedeutung zukommen.

Ziel Erkennen von Schwächen bei Antibiotikaverschreibungen in Krankenhäusern und Vergleich zwischen 2009 und 2014.

Methoden Ein Fragebogen wurde 2014 an alle 380 Ärzte von 7 Krankenhäusern, der Grund-, Regel- und Maximalversorgung verteilt. Erfasst wurden berufliche Entwicklung, Funktion, Kenntnisstand und Vorhandensein und Einsatz von Regeln zum Umgang mit Antibiotika. Die 119 beantworteten Fragebögen von 2014 wurden mit den 3613 aus 2009 verglichen.

Ergebnisse 31% der Fragebögen wurden zurückgeschickt, 53,8% von Assistenzärzten, die Hälfte ohne Facharztanerkennung. 32,8% wurden von Oberärzten, 12,6% von Chefärzten beantwortet. 22.6% waren Internisten, 18,4% Chirurgen, 10,9% Urologen und 9,2% Anaesthesisten. Mehrheitlich wurden Antibiotika täglich verschrieben, von Assistenzärzten zu 66%. 23% der Assistenzärzte gaben an, täglich andere Kollegen zu beraten und 61% mind. 1-mal in der Woche. Der häufigste Anlass hierfür ist die perioperative Antibiotikaprophylaxe (35), der Harnwegsinfekt (32) und die Pneumonie (29). Die Standarddauer der Gabe war 7 Tage bei Pneumonie, 5 Tage beim Harnwegsinfekt und 1 Tag bei der perioperativen Antibiotikaprophylaxe.In fast der Hälfte der Fälle wurde die perioperative Antibiotikaprophylaxe auf 3, 5, 7,8 und 10 Tage ausgedehnt. 93,3% der Ärzte berichteten Antibiotikaleitlinien des eigenen Hauses oder von Fachgesellschaften zu benutzen. Nur 59,3% wussten über die Resistenzen an ihrem Arbeitsplatz Bescheid. 52,1% verschreiben Breitspektrumantibiotika ohne Rücksprache mit dem Oberarzt oder Chefarzt. Im Vergleich zu 2009 sind Kenntnisstand über Antibiotikaresistenzen des Hauses, Benutzung von Leitlinien und Rücksprache mit Ober- bzw. Chefarzt jeweils um ca. 5% angestiegen.

Schlussfolgerung Trotz Verbesserung im Vergleich zu 2009 kannten 38,9% der Befragten die antibiotische Resistenzlage in ihrem Haus nicht und die Hälfte aller Chirurgen setzte die perioperative Prophylaxe länger als 24 Stunden ein. Da die Bereitschaft antibiotische Leitlinien zu benutzen mit 93,3% sehr hoch ist, sollten diese ausgeweitet und regelmäßig an die Resistenzlage angepasst werden. Ferner sollte die perioperative Antibiotikaprophylaxe länger als einen Tag wegen der zusätzlichen Nebenwirkungen ohne weiteren Benefit kritisch hinterfragt werden.

Abridged version of the AWMF guideline for the medical clinical diagnostics of indoor mould exposure: S2K Guideline of the German Society of Hygiene, Environmental Medicine and Preventive Medicine (GHUP) in collaboration with the German Association of Allergists (AeDA), the German Society of Dermatology (DDG), the German Society for Allergology and Clinical Immunology (DGAKI), the German Society for Occupational and Environmental Medicine (DGAUM), the German Society for Hospital Hygiene (DGKH), the German Society for Pneumology and Respiratory Medicine (DGP), the German Mycological Society (DMykG), the Society for Pediatric Allergology and Environmental Medicine (GPA), the German Federal Association of Pediatric Pneumology (BAPP), and the Austrian Society for Medical Mycology (ÖGMM)

This article is an abridged version of the AWMF mould guideline "Medical clinical diagnostics of indoor mould exposure" presented in April 2016 by the German Society of Hygiene, Environmental Medicine and Preventive Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin, GHUP), in collaboration with the above-mentioned scientific medical societies, German and Austrian societies, medical associations and experts. Indoor mould growth is a potential health risk, even if a quantitative and/or causal relationship between the occurrence of individual mould species and health problems has yet to be established. Apart from allergic bronchopulmonary aspergillosis (ABPA) and mould-caused mycoses, only sufficient evidence for an association between moisture/mould damage and the following health effects has been established: allergic respiratory disease, asthma (manifestation, progression and exacerbation), allergic rhinitis, hypersensitivity pneumonitis (extrinsic allergic alveolitis), and increased likelihood of respiratory infections/bronchitis. In this context the sensitizing potential of moulds is obviously low compared to other environmental allergens. Recent studies show a comparatively low sensitizing prevalence of 3-10% in the general population across Europe. Limited or suspected evidence for an association exist with respect to mucous membrane irritation and atopic eczema (manifestation, progression and exacerbation). Inadequate or insufficient evidence for an association exist for chronic obstructive pulmonary disease, acute idiopathic pulmonary hemorrhage in children, rheumatism/arthritis, sarcoidosis and cancer. The risk of infection posed by moulds regularly occurring indoors is low for healthy persons; most species are in risk group 1 and a few in risk group 2 (Aspergillus fumigatus, A. flavus) of the German Biological Agents Act (Biostoffverordnung). Only moulds that are potentially able to form toxins can be triggers of toxic reactions. Whether or not toxin formation occurs in individual cases is determined by environmental and growth conditions, above all the substrate. In the case of indoor moisture/mould damage, everyone can be affected by odour effects and/or mood disorders. However, this is not a health hazard. Predisposing factors for odour effects can include genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for mood disorders may include environmental concerns, anxiety, condition, and attribution, as well as various diseases. Risk groups to be protected particularly with regard to an infection risk are persons on immunosuppression according to the classification of the German Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, KRINKO) at the Robert Koch- Institute (RKI) and persons with cystic fibrosis (mucoviscidosis); with regard to an allergic risk, persons with cystic fibrosis (mucoviscidosis) and patients with bronchial asthma should be protected. The rational diagnostics include the medical history, physical examination, and conventional allergy diagnostics including provocation tests if necessary; sometimes cellular test systems are indicated. In the case of mould infections the reader is referred to the AWMF guideline "Diagnosis and Therapy of Invasive Aspergillus Infections". With regard to mycotoxins, there are currently no useful and validated test procedures for clinical diagnostics. From a preventive medicine standpoint it is important that indoor mould infestation in relevant dimension cannot be tolerated for precautionary reasons. With regard to evaluating the extent of damage and selecting a remedial procedure, the reader is referred to the revised version of the mould guideline issued by the German Federal Environment Agency (Umweltbundesamt, UBA).

Medical diagnostics for indoor mold exposure

In April 2016, the German Society of Hygiene, Environmental Medicine and Preventative Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin (GHUP)) together with other scientific medical societies, German and Austrian medical societies, physician unions and experts has provided an AWMF (Association of the Scientific Medical Societies) guideline 'Medical diagnostics for indoor mold exposure'. This guideline shall help physicians to advise and treat patients exposed indoors to mold. Indoor mold growth is a potential health risk, even without a quantitative and/or causal association between the occurrence of individual mold species and health effects. Apart from the allergic bronchopulmonary aspergillosis (ABPA) and the mycoses caused by mold, there is only sufficient evidence for the following associations between moisture/mold damages and different health effects: Allergic respiratory diseases, asthma (manifestation, progression, exacerbation), allergic rhinitis, exogenous allergic alveolitis and respiratory tract infections/bronchitis. In comparison to other environmental allergens, the sensitizing potential of molds is estimated to be low. Recent studies show a prevalence of sensitization of 3-10% in the total population of Europe. The evidence for associations to mucous membrane irritation and atopic eczema (manifestation, progression, exacerbation) is classified as limited or suspected. Inadequate or insufficient evidence for an association is given for COPD, acute idiopathic pulmonary hemorrhage in children, rheumatism/arthritis, sarcoidosis, and cancer. The risk of infections from indoor molds is low for healthy individuals. Only molds that are capable to form toxins can cause intoxications. The environmental and growth conditions and especially the substrate determine whether toxin formation occurs, but indoor air concentrations are always very low. In the case of indoor moisture/mold damages, everyone can be affected by odor effects and/or impairment of well-being. Predisposing factors for odor effects can be given by genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for impairment of well-being are environmental concerns, anxieties, conditioning and attributions as well as a variety of diseases. Risk groups that must be protected are patients with immunosuppression and with mucoviscidosis (cystic fibrosis) with regard to infections and individuals with mucoviscidosis and asthma with regard to allergies. If an association between mold exposure and health effects is suspected, the medical diagnosis includes medical history, physical examination, conventional allergy diagnosis, and if indicated, provocation tests. For the treatment of mold infections, it is referred to the AWMF guidelines for diagnosis and treatment of invasive Aspergillus infections. Regarding mycotoxins, there are currently no validated test methods that could be used in clinical diagnostics. From the perspective of preventive medicine, it is important that mold damages cannot be tolerated in indoor environments.

In vitro study on the disinfectability of two split-septum needle-free connection devices using different disinfection procedures

This in vitro study investigated the external disinfection of two needle-free connection devices (NFC) using Octeniderm^® (spraying and wiping technique) vs. Descoderm^® pads (wiping technique). The split-septum membrane of the NFC was contaminated with >10⁵ CFU K. pneumoniae or S. epidermidis. The efficacy of the disinfection at 30 sec. exposure time was controlled by taking a swab sample and by flushing the NFC with sterile 0.9% sodium chloride solution. Disinfection with octenidine dihydrochloride 0.1 g, 1-Propanol 30.0 g, and 2-Propanol 45.0 g in 100 g solution was highly effective (CFU reduction ≥4 log) against both microorganisms, whereas the use of 63.1 g 2-Propanol in 100 ml solution led to residual contamination with S. epidermidis. Our investigation underlines that (i) in clinical practice disinfection of NFCs before use is mandatory, and that (ii) details of disinfection technique are of utmost importance regarding their efficacy. Our investigation revealed no significant differences between both split-septum NFC types. Clinical studies are needed to confirm a possible superiority of disinfectants with long-lasting residual antimicrobial activity.

[Hospital disinfection challenges due to multiresistant pathogens in surgery]

The number of antibiotic-resistant pathogens is increasing continuously while the development of new, effective antibiotics cannot be expected in the near future. Postoperative infections represent most of the nosocomial infections by now. Based on this, hygienic strategies regain importance, since a sustainable control of nosocomial infections will not succeed without the implementation of such strategies. In this article, the most important preventive strategies for prevention of infections with MRSA and 3- and 4-fold resistant gram-negative bacteria on the basis of current recommendations of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) are presented.

Krankenhaushygienische Herausforderungen durch multiresistente Erreger in der Chirurgie

Die Anzahl antibiotikaresistenter Erreger steigt kontinuierlich an, ohne dass in den nächsten Jahren mit der Entwicklung neuer, wirksamer Antibiotika zu rechnen sein wird. Postoperative Infektionen stellen mittlerweile mit die häufigsten nosokomialen Infektionen dar. Vor diesem Hintergrund erlangen Hygienestrategien wieder eine neue Bedeutung, ohne deren Umsetzung eine nachhaltige Kontrolle nosokomialer Infektionen nicht gelingen wird. In diesem Artikel werden die wichtigsten Präventionsstrategien zur Prävention einer Infektion mit MRSA sowie 3- und 4-fach resistenten gramnegativen Erregern auf der Grundlage der aktuellen Empfehlungen der Kommission für Krankenhaushygiene und Infektionsprävention (KRINKO) gegeben.

Auf die Präventionsstrategien zu den ebenso als nosokomiale Infektionserreger relevanten Vancomycin-resistenten Enterokokken (VRE) und Clostridium difficile soll in einem zukünftigen Beitrag eingegangen werden, da hierzu die Empfehlungen der KRINKO derzeit noch in Bearbeitung sind.

A new immunoassay to quantify fungal antigens from the indoor mould Aspergillus versicolor

Aspergillus versicolor is among the most commonly found moulds in moisture-damaged buildings and can be associated with adverse health effects in humans. This paper reports the development, validation and application of an enzyme immunoassay to quantify A. versicolor antigens. A sandwich ELISA was developed using polyclonal antibodies that recognize a broad range of A. versicolor proteins present in fungal spores and in mycelia fragments. To validate the new method, A. versicolor antigens were quantified in samples collected from homes with visible mould growth, including dust from vacuumed walls and bulk samples of building materials. Antigen concentrations were compared to the results of a commercial ELISA based on monoclonal antibodies (AveX ELISA, Indoor Biotechnologies, Charlottesville, USA) and correlated with colony forming units (CFU) of A. versicolor. The A. versicolor ELISA was very sensitive with a lower detection limit of 120 pg ml(-1). The assay also showed some reactivity to other moulds with strongest reactions with other Aspergillus species (1-3% reactivity). The new assay detected A. versicolor antigens in a much higher percentage of dust samples (88% vs. 27%) and bulk samples (89% vs. 24%) than the AveX assay. A significant correlation (r = 0.67, and p < 0.0001) was found between antigen concentrations and CFU of A. versicolor. Based on its low detection limit and good correlation with the culture-based method, this new immunoassay seems to be a useful tool for the measurement of A. versicolor exposure levels and a reliable complement to the traditional monitoring techniques, such as mould cultivation or microscopy.

[Farmer's lung antigens in Germany]

Recent studies suggest that besides the long-known farmer's lung antigen sources Saccharopolyspora rectivirgula (Micropolyspora faeni), Thermoactinomyces vulgaris, and Aspergillus fumigatus, additionally the mold Absidia (Lichtheimia) corymbifera as well as the bacteria Erwinia herbicola (Pantoea agglomerans) and Streptomyces albus may cause farmer's lung in Germany. In this study the sera of 64 farmers with a suspicion of farmer's lung were examined for the following further antigens: Wallemia sebi, Cladosporium herbarum, Aspergillus versicolor, and Eurotium amstelodami. Our results indicate that these molds are not frequent causes of farmer's lung in Germany.

Outbreaks of Serratia marcescens in neonatal and pediatric intensive care units: clinical aspects, risk factors and management

The following recommendations are derived from a systematic analysis of 34 Serratia marcescens outbreaks described in 27 publications from neonatal and pediatric intensive care units (NICU, PICU), in which genotyping methods were used to confirm or exclude clonality. The clinical observation of two or more temporally related cases of nosocomial S. marcescens infection should raise the suspicion of an outbreak, particularly in the NICU or PICU setting. Since colonized or infected patients represent the most important reservoir for cross transmission, hygienic barrier precautions (contact isolation/cohortation, the use of gloves and gowns in addition to strictly performed hand disinfection, enhanced environmental disinfection) should immediately be implemented and staff education given. Well-planned sampling of potential environmental sources should only be performed when these supervised barrier precautions do not result in containment of the outbreak. The current strategy of empiric antibiotic treatment should be reevaluated by a medical microbiologist or an infectious disease specialist. Empiric treatment of colonized children should use combination therapy informed by in vitro susceptibility data; in this context the high propensity of S. marcescens to cause meningitis and intracerebral abscess formation should be considered. In vitro susceptibility patterns do not reliably prove or exclude the clonality of the outbreak isolate. Genotyping of the isolates by pulse-field gel electrophoresis or PCR-based methods should be performed, but any interventions to interrupt further nosocomial spread should be carried out without waiting for the results.

Implementing the MRSA recommendations made by the Commission for Hospital Hygiene and Infection Prevention (KRINKO) of 1999 - current considerations by the DGKH Management Board

In Germany, recommendations on dealing with patients who are colonised with methicillin-resistant S. aureus (MRSA) for the inpatient sector have been published in 1999 by the Commission for Hospital Hygiene and Infection Prevention (KRINKO). Some challenges arise with regard to the practical implementation of the KRINKO recommendations. These challenges do not principally question the benefit of the recommendations but have come into criticism from users. In this commentary the German Society for Hospital Hygiene (DGKH) discusses some controversial issues and adds suggestions for unresolved problems regarding the infection control management of MRSA in healthcare settings.

[Risk of infection in the home environment. Plea for a new risk assessment]

Within the last two decades risks posed by infectious diseases outside of hospitals and nursing homes had no high significance in the public perception. The home environment is regarded as a save shelter from infectious risks. In the mean time there have been dramatic socio-demographic, health policy and technological changes which have increased infectious risks outside medical facilities. In Germany up to 1.4 million people with multiple morbidities are nursed at home. Technological changes with the aim to protect the environment, like reduction of water temperature and water volumes in washing processes has lowered the efficacy to control pathogens. Thus it is time to revise the process of risk assessment in which not only aspects of environmental protection but also those of health protection must be taken into account. The article gives an overview of new risks and epidemiological changes and discusses the necessity of a new risk assessment and risk management approach which hopefully will lead to a changing paradigm.

Nosocomial infection: A risk factor for a complicated course in children with respiratory syncytial virus infection – Results from a prospective multicenter German surveillance study

BACKGROUND

Nosocomially acquired respiratory syncytial virus infections (RSV-NI) may cause serious problems in hospitalized paediatric patients. Hitherto, prospectively collected representative data on RSV-NI from multicenter studies in Germany are limited.

METHODS

The DMS RSV Ped database was designed for the prospective multicenter documentation and analysis of clinically relevant aspects of the management of inpatients with RSV-infection. The study covered six consecutive seasons (1999-2005); the surveillance took place in 14 paediatric hospitals in Germany.

RESULTS

Of the 1568 prospectively documented RSV-infections, 6% (n=90) were NI and 94% (n=1478) were community acquired (CA). A significantly higher proportion in the NI group displayed additional risk factors like prematurity, chronic lung disease, mechanical ventilation (med. history), congenital heart disease, and neuromuscular impairment. Of all NI, 55% occurred in preterms (30.6% of all RSV-infections in preterms with severe chronic lung disease of prematurity were NI). Illness severity as well as the total mortality, but not the attributable mortality was significantly higher in the NI group. In the multivariate analysis, NI was significantly associated with the combined outcome 'complicated course of disease'.

CONCLUSION

This is the first prospective multicenter study from Germany, which confirms the increased risk of a severe clinical course in nosocomially acquired RSV-infection. Of great concern is the high rate of (preventable) NI in preterms, in particular in those with severe chronic lung disease or with mechanical ventilation due to other reasons.

Hospital-acquired legionellosis originating from a cooling tower during a period of thermal inversion

A case of hospital-acquired legionellosis occurred in a 75-year-old male patient who underwent surgery due to malignant melanoma. Legionellosis was proven by culture of Legionella pneumophila serogroup 1 from bronchoalveolar lavage (BAL) fluid. Being a chronic smoker the patient used to visit the sickroom balcony that was located about 90 m to the west of a hospital cooling tower. Routine cooling tower water samples drawn during the presumed incubation period revealed 1.0x10(4) CFU/100 ml (L. pneumophila serogroup 1). One of three isolates from the cooling tower water matched the patient's isolate by monoclonal antibody (mab)- and genotyping (sequence-based typing). Horizontal transport of cooling tower aerosols probably was favoured by meteorological conditions with thermal inversion. The case report stresses the importance of routine maintenance and microbiological control of hospital cooling towers.

Wasser als Infektionsquelle in medizinischen Einrichtungen, Prävention und Kontrolle

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

Rotavirus infections in paediatric oncology patients: a matched-pairs analysis

OBJECTIVE

To conduct a systematic investigation of the clinical relevance of rotavirus infection in the setting of paediatric cancer patients receiving intensive chemotherapy.

MATERIAL AND METHODS

Twenty-eight paediatric cancer patients with positive rotavirus antigen tests were eligible for a retrospective case-control study (January 1995-December 2004). Rota-positive patients were compared with 28 rota-negative patients matched for age, underlying disease and chemotherapy. The National Cancer Institute Common Toxicity Criteria were used to determine clinical severity.

RESULTS

Median duration of rota-related symptoms (diarrhoea, fever and vomiting) was 7 days (range 4-34 days; 75th percentile 9 days). Median duration of viral shedding was 17 days (4-73 days; 75th percentile 39.5 days). The rota infection was nosocomially acquired in 19 patients (68%). The proportions of patients with diarrhoea > or =NCI II, fever >39 degrees C, clinically relevant dehydration, metabolic acidosis, mucositis and neutropenia were significantly higher in rota-positive patients. Rota-positive patients tended to have a prolonged period of hospitalization (median 8 versus 4 days; p=0.008). A higher proportion of rota-positive patients had to receive parenteral nutrition and tube feeding (p<0.001).

CONCLUSIONS

Rotavirus is a clinically relevant but preventable pathogen in paediatric cancer patients, since many cases seem to be nosocomial in origin. Rapid microbiological testing and contact precautions should be strictly applied to any symptomatic patient and to their immediate contacts. Prolonged viral shedding in immunocompromised paediatric patients necessitates repeated testing in order to determine the duration of isolation.

Air sampling of Aspergillus fumigatus and other thermotolerant fungi: comparative performance of the Sartorius MD8 airport and the Merck MAS-100 portable bioaerosol sampler

The purpose of our field study was to compare the performance of two portable bioaerosol samplers (Sartorius MD8 airport, and Merck MAS-100) for sampling Aspergillus fumigatus and other airborne thermotolerant fungi. From October 2001 to November 2001, a total of 336 samples were analyzed at 12 sampling days. During the sampling period fungal plate counts ranged from <1 to 300 CFU/m(3) for total thermotolerant fungi and from <1 to 76 CFU/m(3) for A. fumigatus. As compared to the MD8, the relative recovery of the MAS 100 was 0.96 for total thermotolerant fungi and 0.84 for A. fumigatus. We found a good correlation (Pearson's r=0.94 for single, 0.95 for the mean of two, and 0.96 for the mean of three sequential samples) between both portable bioaerosol samplers. The spectrum of thermotolerat fungal genera and Aspergillus species showed only minor differences. We conclude that under the given conditions the results of both samplers are approximately comparable.

Restricted use of glycopeptides in paediatric cancer patients with fever and neutropenia

Until now, studies confirming the safety of glycopeptide restriction in the empirical treatment of prolonged fever and neutropenia included only nine children. In an open-label observational study, the use of teicoplanin in paediatric oncology patients was investigated. A period of unrestricted use (2001-2003) was compared with a second period (2004) following implementation of a restrictive treatment guideline. Empirical first-line treatment consisted of piperacillin/tazobactam; in 2004, fosfomycin was added after 72 h as the second-line combination instead of teicoplanin. In total, 213 episodes (n=163 in 2001-2003; n=50 in 2004) managed with teicoplanin or fosfomycin (only 2004) were eligible. Empirical treatment of fever of unknown origin with teicoplanin was reduced by 97%. In 2004, the mean length of stay was 0.4 days shorter, no infection-related death occurred and no vancomycin-resistant enterococci were detected. Restriction of empirical glycopeptides is safe in paediatric cancer patients after first-line treatment with piperacillin/tazobactam. Fosfomycin appears to offer a feasible and cost-saving alternative in second-line combination therapy.

Nosocomial respiratory syncytial virus infection: Impact of prospective surveillance and targeted infection control

BACKGROUND

Nosocomially acquired respiratory syncytial virus (RSV) infections cause serious problems in hospitalized patients. An increased effort should be made to describe the problems connected with such infections in pediatric hospitals, with the aim of reducing the occurrence of nosocomial RSV infections (NI).

METHODS

A specialized database was introduced for surveillance and a multifaceted barrier concept based on the CDC recommendations was developed for the control of NI in a university children's hospital in Germany.

RESULTS

Between 1999 and 2002 (November 1-April 30), 283 RSV infections (general population) were prospectively documented. Thirty-nine cases (13.8%) were nosocomial infections (NI) with an incidence density (ID) of 0.99/1000 patient days; 48.7% of all NI were found in prematurely born infants. Following the introduction of a surveillance and prevention policy, a 9-fold decrease of the ID (1.67 vs. 0.18/1000 patient-days) was found when comparing the first and the last season. Intensive care treatment was required in 18% of all documented RSV-infections, in 48.7% of all NI cases and in 43.5% of all RSV-infected prematurely born infants. Overall RSV-related mortality was 0.71%.

CONCLUSIONS

Early diagnosis, a strict cohorting and contact isolation policy, and prospective surveillance contribute to the reduction of nosocomial RSV infection.

Norovirus outbreak in a pediatric oncology unit

OBJECTIVE

Norovirus (NV) is an etiologic agent of outstanding importance that can cause severe epidemic gastroenteritis in day-care centers, schools, nursing homes, and hospitals. Therefore NV requires foremost attention as a pathogen responsible for epidemics of gastroenteritis in immunocompromised inpatients. In this study, a NV outbreak in a pediatric oncology unit is described and the consequences for this high-risk population are discussed.

MATERIAL AND METHODS

Stool and vomitus samples from 11 patients were tested for NV and other relevant viruses during the outbreak by reverse transcriptase-polymerase chain reaction (RT-PCR) and/or enzyme-linked immunosorbent assay (ELISA) (whenever an appropriate ELISA was available). Norwalk virus PCR amplifications were sequenced and phylogenetic analysis was performed.

RESULTS

The index patient and the chain of infection were identified. Follow-up investigation surprisingly demonstrated viral shedding for a maximum of 140 days (median 23 days). Three patients experienced severe or life-threatening symptoms, probably related to NV infection.

CONCLUSIONS

In the event of an outbreak of gastroenteritis (involving two or more symptomatic patients) in a pediatric oncology unit, the search for NV in stool or vomitus specimens should be initiated in good time. As long as the data are limited regarding whether a detectable viral antigen or RNA in stools represents an infectious virus, patients have to be isolated as long as the diagnostic assays remain positive. During the acute phase of the illness, health-care workers should wear masks in addition to practicing meticulous hand hygiene with a disinfectant of proven activity against NV. Pediatric oncology patients must be closely monitored during follow-up investigations as they may shed the virus for months. There is some evidence from the outbreak described here that those patients face a greater risk of severe NV-related complications.

Extrinsic allergic alveolitis (hypersensitivity pneumonitis) caused by Sphingobacterium spiritivorum from the water reservoir of a steam iron

A case of extrinsic allergic alveolitis (EAA) caused by Sphingobacterium spiritivorum is described. The symptoms were associated with the use of a steam iron. The water reservoir was heavily contaminated with S. spiritivorum (10(6) CFU ml(-1)). This is the first report of S. spiritivorum as a causative agent of EAA.

Prevention and control of health care-associated waterborne infections in health care facilities

The current article is a review of the public health risks attributable to waterborne pathogens in health care. The consequences of health care-associated infections (HAIs) are discussed. Not only are Legionella spp involved in HAIs, but also Pseudomonas aeruginosa, other gram-negative microorganisms, fungi, and amoeba-associated bacteria. This is particularly noteworthy among immunocompromised patients. New prevention strategies and control measures brought about through advanced planning, facility remodelling and reconstruction, disinfection, and filtration have resulted in a significant reduction of the incidence of waterborne HAIs. The positive consequences of a comprehensive multibarrier approach including prevention and control programs in health care facilities are discussed. Environmental cultures are now integrated within the infection control program of some European countries. In high-risk areas, the application of disposable sterile point-of-use filters for faucets and shower heads appears to be the practice of choice to efficiently control waterborne pathogens and to prevent infections.

[1974-2004: the Commission for Hospital Hygiene has been working for 30 years. From the "old" to the "new" guideline]

After 2 years of preparation, the Commission for Hospital Hygiene, founded in 1974 by the former German Public Health Service, published the "Guideline for Assessment,Prevention, and Controlling of Nosocomial Infections," which represented an exemplarily complete standard for hospital hygiene. In 1997 within the framework of planning the amendment to the Federal Epidemic Law, a new Commission for Hygiene and Infectious Disease Prevention started work and adapted the guideline to meet today's standards of systematic risk analysis and risk management. The amended Infection Protection Act (Infektionsschutzgesetz, IfSG), which came into force in January 2001, installed the Commission for Hospital Hygiene and Infectious Disease Prevention legally and required it to formulate a guideline to decrease the rate of nosocomial infections, the number of outbreaks, and the dissemination of antibiotic-resistant pathogens in healthcare facilities by establishing standards of modern prevention. This article describes the political importance of nosocomial infections for public health as well as the working basis, the methods, and the latest guidelines of the Commission.