[Is Disinfection of Public Surfaces useful for the Prevention of SARS-CoV-2 Infections?] / Ist die Desinfektion öffentlicher Flächen zur Prävention von SARS-CoV-2 ­ infektionen sinnvoll?

Measures to control SARS-CoV-2 often include the regular disinfection of public surfaces. The frequency of SARS-CoV-2 detection on surfaces in the surrounding of confirmed cases was evaluated in this systematic review. Overall, 26 studies showed 0 and 100% rates of contamination with SARS-CoV-2 RNA on surfaces in the surrounding of patients. Seven studies with at least 100 samples mostly showed detection rates between 1.4 and 19%. Two other studies did not detect infectious SARS-CoV-2 on any surface. Similar results were obtained from surfaces in the surrounding of confirmed SARS- and influenza-patients. A contamination of public surfaces with infectious virus is considerably less likely because there are much less potential viral spreaders around a surface, the contact time between a person and the surface is much shorter, and the asymptomatic carriers typically have no symptoms. In addition, a hand contact with a contaminated surface transfers only a small part of the viral load. A simple cleaning reduces the number of infectious viruses already by 2 log10-steps. That is why public surfaces should in general be cleaned because the wide use of biocidal agents for surface disinfection further increases the microbial selection pressure without an expectable health benefit.

An epidemic CC1-MRSA-IV clone yields false-negative test results in molecular MRSA identification assays: a note of caution, Austria, Germany, Ireland, 2020.

We investigated why a clinical meticillin-resistant Staphylococcus aureus (MRSA) isolate yielded false-negative results with some commercial PCR tests for MRSA detection. We found that an epidemic European CC1-MRSA-IV clone generally exhibits this behaviour. The failure of the assays was attributable to a large insertion in the orfX/SCCmec integration site. To ensure the reliability of molecular MRSA tests, it is vital to monitor emergence of new SCCmec types and junction sites.

MRSA Point Prevalence among Health Care Workers in German Rehabilitation Centers: A Multi-Center, Cross-Sectional Study in a Non-Outbreak Setting.

People working in health care services have an increased risk of being infected with methicillin-resistant Staphylococcus aureus (MRSA), though little is known about the prevalence in rehabilitation centers. This cross-sectional study investigated the MRSA prevalence in employees from different rehabilitation centers and aimed to identify risk factors for MRSA transmission. We invited all staff (i.e., with and without patient contact from 22 participating rehabilitation centers; n = 2499) to participate. Study participation included a questionnaire on personal characteristics, lifestyle, personal and occupational risk factors for MRSA and nasal swabs taken by the study team. In total, 1005 persons participated in the study (response: 40.2%). Only four participants carried MRSA (0.40 (95% CI 0.00-1.00) per 100). MRSA carriage did not seem to be occupationally related, as it was found in different occupations with and without direct contact with MRSA patients, as well as in different clinics with different indications and patient clientele. We could not find a clear association between MRSA carriage and potential risk factors due to the low number of cases found. Genotyping revealed the spa types t032 (Barnim epidemic strain) and t1223. Our results suggest a low point prevalence of nasal MRSA colonization in a non-outbreak setting in employees from rehabilitation centers.

Prevalence and predictors of MRSA carriage among employees in a non-outbreak setting: a cross-sectional study in an acute care hospital.

BACKGROUND: Health care workers have an increased risk of being infected with Methicillin-resistant Staphylococcus aureus (MRSA), though little information is available about how prevalent (dormant) MRSA colonization is among health care workers. The aim of this study was to estimate the prevalence and predictors of MRSA carriage in a non-outbreak setting in a university hospital in Germany. METHODS: The entire staff of a university hospital heart center for cardiologic maximum medical care and cardiac surgery were invited to participate in a cross-sectional study (N = 575). The sampled population included health care workers as well as employees with no close patient contact.A questionnaire concerning personal and occupational risk factors as well as lifestyle and demographic factors was applied and nasal swabs were taken. In total 180 persons (31.3%) participated in the study. RESULTS: The majority of study participants had close contact to patients at work (n = 149, 82.8%). Thereof, about one-third had contact to MRSA-patients (n = 53, 35.6%), and most reported wearing protective clothing (n = 44, 83.0%). None of the administrative staff tested positive for MRSA and only one in 149 persons (0.7%, CI 0.00-0.02) with close patient contact carried MRSA (strain CC1-MRSA-IV). This person had close contact to patients with MRSA, less than 1 year of work experience, and had been treated with antibiotics within the last 12 months. CONCLUSION: The results of our study suggest low point prevalence rates of MRSA colonization in health care workers in a non-outbreak setting.

Air quality in the operating room: Surgical site infections, HVAC systems and discipline - position paper of the German Society of Hospital Hygiene (DGKH).

In recent years, there has been an ongoing discussion about the value of laminar airflow (LAF=low turbulence displacement ventilation) in the operating room for prevention of surgical site infections (SSI). Some publications, e.g., from the WHO, issued the demand to no longer build LAF ceilings in operating rooms. The present statement deals critically with this position and justifies the use of LAF ceilings in different ways: Many of the papers cited by the WHO and others for the case against LAF do not provide reliable data.The remaining studies which might be used for answering the question give quite different results, also in favor of LAF.The size of the LAF ceiling in many studies is not given or mostly too small in comparison to actual technical requirements.LAF in different countries can mean quite different techniques (e.g., the US in comparison to Germany) so that the results of studies that do not take this into account may not be comparable.LAF has positive effects in terms of reducing particulate and bacterial load, associated with increased airflow in the surgical working area. A reduction of carcinogenic substances in the air may also be assumed, which would increase workers' safety. Thus, this paper recommends building LAF ceilings in the future as well, depending on the operations intended. Further, this paper gives an overview of possible reasons for surgical site infections and highlights the importance of discipline in the operating theatre.

Investigation and Evaluation of Potential Aerosol Release by Maquet/Getinge Heater-Cooler Units Used during Cardiac Surgery.

BACKGROUND: Heater-Cooler units (HCUs) supply tempered water through blood heat exchangers and through warming/cooling blankets to control the body temperature of heart surgery patients. Bacteria which potentially colonize the stored water may escape from the tank into the environment and are carried by the device's cooling air exhaust into the sterile field and finally may infect open chest heart surgery patients. Reports from several countries are connecting the infection of open chest heart surgery patients to airborne transmitted Mycobacteria chimaera which were found in the water of heater-cooler devices. As a consequence of the vigilance system for medical products, we investigated the potential release and the possible transmission of bacteria from the tank water into the sterile operating field. MATERIALS AND METHODS: In the absence of an evaluation standard for this problem, measurable acceptance criteria for particle releases and a qualitative method for bacteria transmission assessment have been deployed. To assess potential bacteria transmission into the sterile field, tank water of the test devices was inoculated with high concentrations of Pseudomonas aeruginosa (reference strain ATCC15442) and operated in an operating room with simulated use. RESULTS: The particle release at the tank lids of the Maquet/Getinge HCU 30 and HCU 40 during the filling of the tubes with water (deaeration) and during the removal of water from the tubes (emptying) increased slightly, but close to the blank readings for the larger particles. As expected, the particle release at the cooling air grids was higher than around the tank openings. Consistent with the particle measurements, no bacteria from the tank water were found in the sterile field during simulated use of all highly inoculated machines in an operating room. CONCLUSION: In summary, we assess the risk of infecting open chest heart surgery patients with aerosol-transmitted bacteria from water inside the Maquet/Getinge HCU 40, HCU 30 to be negligible, if handled in accordance with common clinical hygienic precautions.

Molecular Typing of ST239-MRSA-III From Diverse Geographic Locations and the Evolution of the SCCmec III Element During Its Intercontinental Spread.

ST239-MRSA-III is probably the oldest truly pandemic MRSA strain, circulating in many countries since the 1970s. It is still frequently isolated in some parts of the world although it has been replaced by other MRSA strains in, e.g., most of Europe. Previous genotyping work (Harris et al., 2010; Castillo-Ramírez et al., 2012) suggested a split in geographically defined clades. In the present study, a collection of 184 ST239-MRSA-III isolates, mainly from countries not covered by the previous studies were characterized using two DNA microarrays (i) targeting an extensive range of typing markers, virulence and resistance genes and (ii) a SCCmec subtyping array. Thirty additional isolates underwent whole-genome sequencing (WGS) and, together with published WGS data for 215 ST239-MRSA-III isolates, were analyzed using in-silico analysis for comparison with the microarray data and with special regard to variation within SCCmec elements. This permitted the assignment of isolates and sequences to 39 different SCCmec III subtypes, and to three major and several minor clades. One clade, characterized by the integration of a transposon into nsaB and by the loss of fnbB and splE was detected among isolates from Turkey, Romania and other Eastern European countries, Russia, Pakistan, and (mainly Northern) China. Another clade, harboring sasX/sesI is widespread in South-East Asia including China/Hong Kong, and surprisingly also in Trinidad & Tobago. A third, related, but sasX/sesI-negative clade occurs not only in Latin America but also in Russia and in the Middle East from where it apparently originated and from where it also was transferred to Ireland. Minor clades exist or existed in Western Europe and Greece, in Portugal, in Australia and New Zealand as well as in the Middle East. Isolates from countries where this strain is not epidemic (such as Germany) frequently are associated with foreign travel and/or hospitalization abroad. The wide dissemination of this strain and the fact that it was able to cause a hospital-borne pandemic that lasted nearly 50 years emphasizes the need for stringent infection prevention and control and admission screening.

Variability of SCCmec elements in livestock-associated CC398 MRSA.

The most common livestock-associated lineage of methicillin-resistant Staphylococcus aureus (MRSA) in Western Europe is currently clonal complex (CC) 398. CC398-MRSA spread extensively across livestock populations in several Western European countries, and livestock-derived CC398-MRSA strains can also be detected in humans. Based on their SCCmec elements, different CC398 strains can be distinguished. SCCmec elements of 100 veterinary and human CC398-MRSA isolates from Germany and Austria were examined using DNA microarray-based assays. In addition, 589 published SCC and/or genome sequences of CC398-MRSA (including both, fully finished and partially assembled sequences) were analysed by mapping them to the probe sequences of the microarrays. Several isolates and sequences showed an insertion of a large fragment of CC9 genomic DNA into the CC398 chromosome. Fifteen subtypes of SCCmec elements were detected among the 100 CC398 isolates and 41 subtypes could be discerned among the published CC398 sequences. Eleven of these were also experimentally detected within our strain collection, while four subtypes identified in the isolates where not found among the sequences. A high prevalence of heavy metal resistance genes, especially of czrC, was observed among CC398-MRSA. A possible co-selection of resistances to antibiotics and zinc/copper supplements in animal feed as well as a spill-over of SCCmec elements that have evolved in CC398-MRSA to other, possibly more virulent and/or medically relevant S. aureus lineages might pose public health problems in future.

Dissemination of high-level mupirocin-resistant CC22-MRSA-IV in Saxony.

Mupirocin is used for eradicating methicillin-resistant S. aureus (MRSA) in nasal colonization. A plasmid-borne gene, mupA, is associated with high-level mupirocin resistance. Despite the fact that, among all MRSA from a tertiary care center in the German state of Saxony, the prevalence of mupA, encoding high-level mupirocin resistance, was approximately 1% over a 15-year period from 2000-2015, a sharp increase to nearly 20% was observed in 2016/2017. DNA microarray profiling revealed that this was due to the dissemination of a variant of CC22-MRSA-IV ("Barnim Epidemic Strain" or "UK-EMRSA-15"), which, in addition to mecA, harbors mupA, aacA-aphD, qacA, and - in most isolates - erm(C). In order to prevent therapy failures and a further spread of this strain, the use of mupirocin should be more stringently controlled as well as guided by susceptibility testing. In addition, MRSA decolonization regimens that rely on other substances, such as betaisodona, polyhexanide or octenidine, should be considered.

Diversity of SCCmec Elements in Staphylococcus aureus as Observed in South-Eastern Germany.

SCCmec elements are very important mobile genetic elements in Staphylococci that carry beta-lactam resistance genes mecA/mecC, recombinase genes and a variety of accessory genes. Twelve main types and a couple of variants have yet been described. In addition, there are also other SCC elements harbouring other markers. In order to subtype strains of methicillin-resistant S. aureus (MRSA) based on variations within their SCCmec elements, 86 markers were selected from published SCC sequences for an assay based on multiplexed primer extension reactions followed by hybridisation to the specific probes. These included mecA/mecC, fusC, regulatory genes, recombinase genes, genes from ACME and heavy metal resistance loci as well as several genes of unknown function. Hybridisation patterns for published genome or SCC sequences were theoretically predicted. For validation of the microarray based assay and for stringent hybridisation protocol optimization, real hybridization experiments with fully sequenced reference strains were performed modifying protocols until yielded the results were in concordance to the theoretical predictions. Subsequently, 226 clinical isolates from two hospitals in the city of Dresden, Germany, were characterised in detail. Beside previously described types and subtypes, a wide variety of additional SCC types or subtypes and pseudoSCC elements were observed as well as numerous composite elements. Within the study collection, 61 different such elements have been identified. Since hybridisation cannot recognise the localisation of target genes, gene duplications or inversions, this is a rather conservative estimate. Interestingly, some widespread epidemic strains engulf distinct variants with different SCCmec subtypes. Notable examples are ST239-MRSA-III, CC5-, CC22-, CC30-, and CC45-MRSA-IV or CC398-MRSA-V. Conversely, identical SCC elements were observed in different strains with SCCmec IVa being spread among the highest number of Clonal Complexes. The proposed microarray can help to distinguish isolates that appear similar or identical by other typing methods and it can be used as high-throughput screening tool for the detection of putative new SCC types or variants that warrant further investigation and sequencing. The high degree of diversity of SCC elements even within so-called strains could be helpful for epidemiological typing. It also raises the question on scale and speed of the evolution of SCC elements.

Reducing Mediastinitis after Sternotomy with Combined Chlorhexidine-Isopropyl Alcohol Skin Disinfection: Analysis of 3,000 Patients.

BACKGROUND: Reducing surgical site infections (SSI) following median sternotomy remains a challenge for cardiac surgeons. Standard prophylaxis of SSI at our institution includes pre-operative skin disinfection with isopropyl alcohol (IPA). The addition of chlorhexidine gluconate (CHG) has the theoretical advantage of longer antimicrobial activity (>48h), compared with 2 h for IPA alone. OBJECTIVES: This prospective registry study was conducted to evaluate the effect of combined CHG-IPA (ChloraPrep®) skin antiseptic on the incidence of sternal surgical incision infections after cardiac surgical procedures via median sternotomy. METHODS: Between September 2011 and November 2013, 3,942 consecutive patients underwent cardiac surgery with median sternotomy at our institution. Among them, 2,985 patients met inclusion criteria and were enrolled in the study. The complete cohort was prospectively divided into two registries. In registry 1 (1,523 patients), CHG-IPA was used to disinfect skin at the thoracic operative site prior to incision. In registry 2 (1,462 patients), single IPA disinfection was used. The primary endpoint was the incidence of post-sternotomy mediastinitis within 30 d of surgery. Secondary endpoints were SSI of any other kind, 30-d survival, and hospital length of stay. RESULTS: Both registries were well matched in baseline characteristics and main risk factors. Post-operative data analysis revealed reduction in the rate of post-sternotomy mediastinitis in registry 1 (29 patients, 1.9%) versus registry 2 (62 patients, 4.2%), p = 0.0002. No relevant difference in incidence of other surgical site infections, length of hospital stay, and 30-d mortality was found. CONCLUSIONS: Skin disinfection with combined chlorhexidine-isopropyl alcohol reduced the incidence of mediastinitis in elective adult cardiac surgery with median sternotomy but did not affect other types of surgical site infections.

Development and first data of a customized short tracheal cannula based on digital data.

PURPOSE: At the moment, there is an inadequate margin fit of commercially available stoma buttons. The aim of the present study was to develop a customized short tracheal cannula based on digital data. Furthermore, the applied material has to be evaluated considering germ colonization and appropriate cleaning procedures. METHODS: Computed tomographies of 53 patients who underwent laryngectomy were surveyed. Based on the digital data, a customized short tracheal cannula was created and manufactured from silicone. The new cannula was incorporated in ten patients and worn for 4 weeks. A clinical examination of an otolaryngologist and subjective assessment of the patients were carried out. Furthermore, microbiological test considering germ colonization was performed. RESULTS: The customized short tracheal cannula could be incorporated in all patients. The clinical results showed no irritation or mucosal lesions. The subjective individual evaluation by the patients was promising. The proposals for improvement could be considered. The microbiological examination revealed a higher contamination of the silicone compared to the silver cannulas. Both chemical and mechanical decontamination showed sufficient results. CONCLUSION: A workflow for development and manufacturing of a customized short tracheal cannula from digital data could be established. The cannula is compatible to standard equipment and routine cleaning procedures. Clinical studies are required to evaluate the potential benefit for patients.

A single standardized practical training for surgical scrubbing according to EN1500: effect quantification, value of the standardized method and comparison with clinical reference groups.

UNLABELLED: The standardized training of practical competences in skills labs is relatively new among German Medical Faculties. The broad acceptance and outstanding evaluation results do not provide objective data on the efficiency and cost-efficiency of these trainings. This study aims on the quantification of the teaching effect of the surgical scrubbing technique EN1500 and its comparison with clinical references of OR personnel. METHODS: 161 4(th) year medical students were randomized into intervention and control group. The intervention group received a 45 minute standardized peer-teaching training of practical competences necessary in the OR including the scrubbing according to EN1500. Fluorescence dye was mixed in the disinfectant solution. After hand disinfection, standardized fotographs and semi-automated digital processing resulted in quantification of the insufficiently covered hand area. These results were compared with the control group that received the training after the test. In order to provide information on the achieved clinical competence level, the results were compared with the two clinical reference groups. RESULTS: The intervention group remained with 4,99% (SD 2,34) insufficiently covered hand area after the training compared to the control group 7,33% (SD 3,91), p<0,01. There was no significant difference between control group and reference groups: surgeons 9,32% (SD 4,97), scrub nurses 8,46% (SD 4,66). The student intervention group showed results that were significantly better than the clinical references. The methodic mistake remained negligible. In the sub-group analysis, the students with low or medium experience in surgical scrubbing and hand disinfection derived highest benefit from the training, whereas students with no or high experience did benefit less. All participants showed better results on hand palms compared to back of hand areas. DISCUSSION: A single standardized peer-teaching of surgical scrubbing and hand disinfection according to EN1500 is sufficient to improve the measurable coverage of hand area and reduce the disinfection gap by 1/3. In absolute measures, the competence level of experienced surgeons and scrub nurses is achieved or even exceeded.

Clonal replacement of epidemic methicillin-resistant Staphylococcus aureus strains in a German university hospital over a period of eleven years.

Worldwide, methicillin-resistant Staphylococcus aureus (MRSA) pose an increased risk for healthcare- and community-associated infections. Since the first report of MRSA in England in 1961, several distinct clones or strains have emerged. Changes within the MRSA population of whole countries, small regions or of single hospitals have been observed with some clones replacing others. In this study, the clonal replacement of MRSA isolates in a South-eastern German tertiary care hospital between 2000 and 2010 is described based on microarray analyses of 778 isolates and at least 50 MRSA per year. Within these eleven years, four common epidemic strains, CC22-MRSA-IV, CC45-MRSA-IV, CC5/ST228-MRSA-I (including a variant with a truncated SCCmec element) and CC5-MRSA-II were identified. The PVL-negative CC22-MRSA-IV strain (Barnim Epidemic Strain, UK-EMRSA-15) was detected for the first time in 2001 and its abundance increased since then to 58.6% in 2010. CC5-MRSA-II increased from 2% (2000) to about 30% (2003), and since then it fluctuates between 23 and 37% of isolates. CC5/ST228-MRSA-I decreased from about the half of tested isolates (2000) to 2.3% (2010). A similar trend was observed for CC45-MRSA-IV, which decreased drastically down to 3.4% in 2010 after reaching a maximum of 62.0% in 2002. Seventeen other PVL-negative MRSA strains were identified sporadically with no significant trend being observed. Seven PVL-positive MRSA strains were found, but they remained rare during the study period accounting together for 2.7% of isolates.

A field guide to pandemic, epidemic and sporadic clones of methicillin-resistant Staphylococcus aureus.

In recent years, methicillin-resistant Staphylococcus aureus (MRSA) have become a truly global challenge. In addition to the long-known healthcare-associated clones, novel strains have also emerged outside of the hospital settings, in the community as well as in livestock. The emergence and spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an additional cause for concern. In order to provide an overview of pandemic, epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference strains from the United States have been genotyped by DNA microarray analysis. This technique allowed the assignment of the MRSA isolates to 34 distinct lineages which can be clearly defined based on non-mobile genes. The results were in accordance with data from multilocus sequence typing. More than 100 different strains were distinguished based on affiliation to these lineages, SCCmec type and the presence or absence of PVL. These strains are described here mainly with regard to clinically relevant antimicrobial resistance- and virulence-associated markers, but also in relation to epidemiology and geographic distribution. The findings of the study show a high level of biodiversity among MRSA, especially among strains harbouring SCCmec IV and V elements. The data also indicate a high rate of genetic recombination in MRSA involving SCC elements, bacteriophages or other mobile genetic elements and large-scale chromosomal replacements.

One-day point prevalence of emerging bacterial pathogens in four secondary and five tertiary care German hospitals - results from a pilot study of the German Society for Hospital Hygiene (Deutsche Gesellschaft für Krankenhaushygiene, DGKH).

OBJECTIVE: Data on the prevalence of emerging bacterial pathogens like extended-spectrum-lactamase-building (ESBL) Gram negative organisms, multiresistant Pseudomonas and Acinetobacter species or toxin-building Clostridium difficile in German hospitals are sparse. To provide data for different regions in Germany, a one-day point prevalence study with five tertiary care hospitals and four secondary care hospitals was conducted on the 10(th) of February 2010. METHOD: For participating hospitals, the level of care (primary/secondary/tertiary), staffing with infection prevention personnel, availability of a MRSA-screening, microbiological support and the prevalence of five emerging bacterial pathogens in intensive care, surgical and medical wards was assessed by questionnaire. RESULTS: Overall, 3411 patients were included. In tertiary hospitals, the following prevalences were given: MRSA 1.8%, ESBL E. coli 0.45%, ESBL Klebsiella spp. 0.41%, multiresistant Pseudomonas 0.53%, multiresistant Acinetobacter species 0.15%, VRE 0.49% und Clostridium difficile 1.01%. In secondary hospitals, as prevalences resulted for MRSA 3.48%, ESBL E. coli 0.4%, ESBL Klebsiella spp. 0.4%, multiresistant Pseudomonas 0%, multiresistant Acinetobacter species 0%, VRE 0.13% und Clostridium difficile 1.34%. DISCUSSION: The prevalence of MRSA found is comparable to other prevalence studies published in the last years, but remarkably higher than reported by the German National Surveillance System (KISS). As no prevalence data for other pathogens as MRSA could be found, only data from the ITS-KISS are available for comparison. Again, the prevalences found in the present study are much higher than reported by the KISS. Whether this is by chance or indicates a systematic underreporting in the KISS remains unclear. CONCLUSION: The results from this one day point prevalence study show that prevalences of emerging bacterial pathogens differ markedly between regions, departments and hospitals. This can be explained by regional, methodical and other difference associated with the level of care provided by these hospitals. Still, the prevalences found fit well to other prevalence studies from the last years but are remarkably higher than to be expected by the KISS. As questionnaire-based one-day prevalence studies have been shown to be inexpensive and feasible, such studies, using a fixed day and protocol, should be extendedly used in the future to collect representative data for Germany. By such initiatives, scientific societies as the DGKH can take part in collecting valuable epidemiological data of emerging bacterial pathogens.

Infection prevention during anaesthesia ventilation by the use of breathing system filters (BSF): Joint recommendation by German Society of Hospital Hygiene (DGKH) and German Society for Anaesthesiology and Intensive Care (DGAI).

An interdisciplinary working group from the German Society of Hospital Hygiene (DGKH) and the German Society for Anaesthesiology and Intensive Care (DGAI) worked out the following recommendations for infection prevention during anaesthesia by using breathing system filters (BSF). The BSF shall be changed after each patient. The filter retention efficiency for airborne particles is recommended to be >99% (II). The retention performance of BSF for liquids is recommended to be at pressures of at least 60 hPa (=60 mbar) or 20 hPa above the selected maximum ventilation pressure in the anaesthetic system. The anaesthesia breathing system may be used for a period of up to 7 days provided that the functional requirements of the system remain unchanged and the manufacturer states this in the instructions for use.THE BREATHING SYSTEM AND THE MANUAL VENTILATION BAG ARE CHANGED IMMEDIATELY AFTER THE RESPECTIVE ANAESTHESIA IF THE FOLLOWING SITUATION HAS OCCURRED OR IT IS SUSPECTED TO HAVE OCCURRED: Notifiable infectious disease involving the risk of transmission via the breathing system and the manual bag, e.g. tuberculosis, acute viral hepatitis, measles, influenza virus, infection and/or colonisation with a multi-resistant pathogen or upper or lower respiratory tract infections. In case of visible contamination e.g. by blood or in case of defect, it is required that the BSF and also the anaesthesia breathing system is changed and the breathing gas conducting parts of the anaesthesia ventilator are hygienically reprocessed.Observing of the appropriate hand disinfection is very important. All surfaces of the anaesthesia equipment exposed to hand contact must be disinfected after each case.

MRSA in a large German University Hospital: Male gender is a significant risk factor for MRSA acquisition.

BACKGROUND: The continually rising number of hospital acquired infections and particularly MRSA (Methicillin-resistant Staphylococcus aureus) colonization poses a major challenge from both clinical and epidemiological perspectives. The assessment of risk factors is vital in determining the best prevention, diagnosis and treatment strategies. MATERIALS AND METHODS: We analyzed 798 cases of MRSA in a large German University Hospital over a 7-year period. Data was collected retro- and prospectively including patient age, sex, type of ward and duration of inpatient stay. In addition we analyzed all cases on ICU with regards to cross infection and MRSA genotyping via DNA MicroArray Technology. The years 2004 to 2007 were analyzed with a specific focus on gender. RESULTS: Male gender is significantly correlated with increased risk of MRSA acquisition (p<0.001), the predominant setting for MRSA is on ICU. 75% of the MRSA positive patients are over 50 years of age (average age 59.8 years). The inpatient time was 4.15 times higher in MRSA carriers compared with non-MRSA cases, however this was not significant. MRSA genotyping on ICU showed mainly the subtypes ST 5, ST 22, ST 228, however cross contamination with identical genotypes was only detected in a minority of cases (5 out of 22). CONCLUSION: Unlike previous studies which show no or inconclusive evidence of gender as a risk factor, our data confirm that male gender is a significant risk factor for MRSA carrier status. Further research will be required to investigate the aetiology of these findings.

Comparison of commercially available media for the recovery of Legionella species.

A lack of standardization of environmental monitoring techniques for Legionella spp. complicates the interpretation and comparison of results from different institutions. Since the quality of the culture media has enormous effect on the recovery of Legionella spp. a comparative assessment of commercially available media from four manufactures (Becton Dickenson, BioMerieux, Heipha, and Oxoid) was performed. For this, samples containing infected Acanthamoeba castellanii cells, samples from the External Quality Assurance Scheme (EQA) run by the Health Protection Agency in London and water samples from a hospital in Dresden, Germany, were investigated. The glycine-containing media (GVPC) from four manufactures were equally effective in growing legionellae. However, this medium formulation inhibited some of the non-pneumophila strains tested which was not observed with the selective BMPA and non-selective BCYE-agar.

A pilot study of three methods for the reduction of bacterial contamination of dental unit water systems in routine use.

Three different methods for minimizing the bacterial contamination of the water system in a SIRONA C2 type dental unit were investigated sequentially. Without any decontamination method, water from the hand piece, air-water-jet and mouthwash were continuously contaminated by 10(3) to 10(5) colony forming units (cfu) of aerobic mesophilic bacteria per milliliter. A reduction to below 100 cfu/ml was achieved by continuous adding of a chemical microbicide based on hydrogen peroxide and silver ions. However, this was only possible after rinsing the system thoroughly for at least two minutes after interruptions of the treatment. Long-lasting low counts of below 100/ml were obtained by means of an in-line bacteria filter, in connection with the provision of a thermo-chemical or thermal decontamination of the water pipes and hand pieces after the filter. The electrolyte release of chlorine from the dental unit tap water by anodic oxidation without addition of any chemical disinfectant also resulted in continuously low colony numbers of the water. In this case, regular decontamination of the end parts of the pipes and hand pieces was not necessary.