The Increase in Invasive Bacterial Infections With Respiratory Transmission in Germany, 2022/2023.

BACKGROUND: In late 2022, health care institutions in Germany reported an unusual number of severe, invasive bacterial infections in association with a high incidence of viral respiratory infections. METHODS: We analyzed routine data on invasive infections due to Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus pyogenes (2017-2023) from a voluntary, laboratory-based surveillance system involving continuously participating facilities providing diagnostic routine data that cover approximately one-third of the German population. RESULTS: In the first quarter (Q1) of 2023, the number of invasive S. pyogenes isolates rose by 142% (n = 837 vs. mean Q1/2017-2019 = 346, 95% CI [258; 434]), while the number of H. influenzae isolates rose by 90% (n = 209 in Q1/2023 vs. mean Q1/2017-2019 = 110, 95% CI [79; 142]), compared to pre-pandemic seasonal peak values. The number of invasive S. pneumoniae isolates was high in two quarters (n = 1732 in Q4/2022 und Q1/2023). Adults aged 55 and older and children younger than 5 years were most affected by invasive H. influenzae, S. pneumoniae, and S. pyogenes infections. N. meningitidis was most commonly found in children under age 5. CONCLUSION: The reason for the marked rise in invasive bacterial infections may be an increased circulation of respiratory pathogens and elevated susceptibility in the population after relaxation of the measures taken to prevent COVID-19 infection. Coinfections with respiratory viruses may have reinforced this effect. We recommend continuous surveillance, preventive measures such as raising awareness about invasive bacterial diseases, and vaccination as recommended by the German Standing Committee on Vaccinations (STIKO).

Reported antibiotic use among patients in the multicenter ANDEMIA infectious diseases surveillance study in sub-saharan Africa.

BACKGROUND: Exposure to antibiotics has been shown to be one of the drivers of antimicrobial resistance (AMR) and is critical to address when planning and implementing strategies for combatting AMR. However, data on antibiotic use in sub-Saharan Africa are still limited. Using hospital-based surveillance data from the African Network for Improved Diagnostics, Epidemiology and Management of Common Infectious Agents (ANDEMIA), we assessed self-reported antibiotic use in multiple sub-Saharan African countries. METHODS: ANDEMIA included 12 urban and rural health facilities in Côte d'Ivoire, Burkina Faso, Democratic Republic of the Congo, and Republic of South Africa. Patients with acute respiratory infection (RTI), acute gastrointestinal infection (GI) and acute febrile disease of unknown cause (AFDUC) were routinely enrolled, and clinical, demographic, socio-economic and behavioral data were collected using standardized questionnaires. An analysis of ANDEMIA data from February 2018 to May 2022 was conducted. Reported antibiotic use in the ten days prior to study enrolment were described by substance and by the WHO AWaRe classification ("Access", "Watch", "Reserve", and "Not recommended" antibiotics). Frequency of antibiotic use was stratified by location, disease syndrome and individual patient factors. RESULTS: Among 19,700 ANDEMIA patients, 7,258 (36.8%) reported antibiotic use. A total of 9,695 antibiotics were reported, including 54.7% (n = 5,299) from the WHO Access antibiotic group and 44.7% (n = 4,330) from the WHO Watch antibiotic group. The Watch antibiotic ceftriaxone was the most commonly reported antibiotic (n = 3,071, 31.7%). Watch antibiotic use ranged from 17.4% (56/322) among RTI patients in Côte d'Ivoire urban facilities to 73.7% (630/855) among AFDUC patients in Burkina Faso urban facilities. Reported antibiotic use included WHO Not recommended antibiotics but no Reserve antibiotics. CONCLUSIONS: Reported antibiotic use data from this multicenter study in sub-Saharan Africa revealed a high proportion of WHO Watch antibiotics. Differences in Watch antibiotic use were found by disease syndrome, country and health facility location, which calls for a more differentiated approach to antibiotic use interventions including further evaluation of accessibility and affordability of patient treatment.

Antimicrobial resistance in Germany and Europe - A systematic review on the increasing threat accelerated by climate change.

Background: Antimicrobial Resistance (AMR) is one of the top ten global public health threats facing humanity, alongside climate change. Here, we aim to summarise the effects of climate change (i.e. raise of temperature, change in humidity or precipitation) on spread of antibiotic resistance and on infections with antibiotic-resistant bacteria in Germany. Methods: We conducted a literature search with articles published between January 2012 and July 2022. Two authors screened titles, abstracts and full texts and extracted the data systematically. Results: From originally 2,389 titles, we identified six studies, which met our inclusion criteria. These studies show that an increase in temperature may lead to higher antibiotic resistance rates and an increased risk of colonisation as well as spread of pathogens. Furthermore, the number of healthcare-associated infections increases with increased temperature. Data indicate that higher antibiotic use is present in areas with warmer mean temperature. Conclusions: European data are scarce, but all studies identified point towards an increasing AMR burden due to climate change. However, further studies are needed to draw attention to the links between climatic factors and AMR and develop targeted preventive measures.

[Therapy-relevant antibiotic resistances in a One Health context]. / Therapierelevante Antibiotikaresistenzen im One-Health-Kontext.

One Health refers to a concept that links human, animal, and environmental health. In Germany, there is extensive data on antibiotic resistance (AMR) and multidrug-resistant (micro)organisms (MDRO) in human and veterinary medicine, as well as from studies in various environmental compartments (soil, water, wastewater). All these activities are conducted according to different specifications and standards, which makes it difficult to compare data. A focus on AMR and MDRO of human therapeutic importance is helpful to provide some guidance. Most data are available across sectors on methicillin-resistant Staphylococcus aureus (MRSA) and multiresistant Enterobacterales such as Escherichia coli and Klebsiella pneumoniae. Here, the trends of resistance are heterogeneous. Antibiotic use leads to MRE selection, which is well documented. Success in minimizing antibiotic use has also been demonstrated in recent years in several sectors and could be correlated with success in containing AMR and MDRO (e.g., decrease in MRSA in human medicine). Sector-specific measures to reduce the burden of MDRO and AMR are also necessary, as not all resistance problems are linked to other sectors. Carbapenem resistance is still rare, but most apparent in human pathogens. Colistin resistance occurs in different sectors but shows different mechanisms in each. Resistance to antibiotics of last resort such as linezolid is rare in Germany, but shows a specific One Health correlation. Efforts to harmonize methods, for example in the field of antimicrobial susceptibility testing and genome-based pathogen and AMR surveillance, are an important first step towards a better comparability of the different data collections.

[Strategies for the rational use of antibiotics in the outpatient sector-results of a workshop with key stakeholders in the healthcare system]. / Strategien zum rationalen Antibiotikaeinsatz im ambulanten Sektor ­ Ergebnisse eines Workshops mit wichtigen Akteuren des Gesundheitswesens.

In November 2021, the Federal Ministry of Health (BMG) organized the one-day virtual workshop "Rational antibiotic use in the outpatient sector - potential and opportunities for change" with scientific support from the Robert Koch Institute (RKI). The aim was to collect strategies for promoting the appropriate use of antibiotics in the outpatient sector. With 114 participants, important stakeholders of the healthcare system were represented. In the run-up to the event, the invited participants had already been asked to take part in an online survey on perspectives, experiences, and ideas for the rational use of antibiotics in the outpatient sector. The answers were analyzed and presented at the workshop.The workshop was introduced with plenary lectures on the German Antibiotic Resistance Strategy (DART) and the antibiotic resistance situation in Germany. All experts participated in 10 working group discussions; the resulting findings were presented in the concluding plenary session. In this conference report, selected aspects of these discussions are presented. The insights gained are to be incorporated into the "DART 2030" strategy.

[Recording of SARS-CoV-2 laboratory tests in Germany]. / Erfassung der Labortestungen auf SARS-CoV-2 in Deutschland.

The collection of data on SARS-CoV­2 tests is central to the assessment of the infection rate in the context of the COVID-19 pandemic. At the Robert Koch Institute (RKI), data collected from various laboratory data recording systems are consolidated. First, this article aims to exemplify significant aspects regarding test procedures. Subsequently the different systems for recording laboratory tests are described and test numbers from the RKI test laboratory query and the laboratory-based SARS-CoV­2 surveillance as well as accounting data from the Association of Statutory Health Insurance Physicians for SARS-CoV­2 laboratory tests are shown.Early in the pandemic, the RKI test laboratory query and the laboratory-based SARS-CoV­2 surveillance became available and able to evaluate data on performed tests and test capacities. By recording the positive and negative test results, statements about the total number of tests and the proportion of positive test rates can be made. While the aggregate test numbers are largely representative nationwide, they are not always representative at the state and district level. The billing data of the Association of Statutory Health Insurance Physicians can complement the laboratory data afterwards. In addition, it can provide a retrospective assessment of the total number of SARS-CoV­2 numbers in Germany, because the services provided by statutory health insurers (around 85% of the population in Germany) are included. The various laboratory data recording systems complement one another and the evaluations flow into the recommended measures for the pandemic response.

High impact of COVID-19 in long-term care facilities, suggestion for monitoring in the EU/EEA, May 2020.

Residents in long-term care facilities (LTCF) are a vulnerable population group. Coronavirus disease (COVID-19)-related deaths in LTCF residents represent 30-60% of all COVID-19 deaths in many European countries. This situation demands that countries implement local and national testing, infection prevention and control, and monitoring programmes for COVID-19 in LTCF in order to identify clusters early, decrease the spread within and between facilities and reduce the size and severity of outbreaks.

Application of a new methodology and R package reveals a high burden of healthcare-associated infections (HAI) in Germany compared to the average in the European Union/European Economic Area, 2011 to 2012.

BackgroundHealthcare-associated infections (HAIs) pose a major challenge to health systems. Burden of disease estimations in disability-adjusted life years (DALYs) are useful for comparing and ranking HAIs.AimTo estimate the number of five common HAIs, their attributable number of deaths and burden for Germany.MethodsWe developed a new method and R package that builds on the approach used by the Burden of Communicable Diseases in Europe (BCoDE) project to estimate the burden of HAIs for individual countries. We used data on healthcare-associated Clostridioides difficile infection, healthcare-associated pneumonia, healthcare-associated primary bloodstream infection, healthcare-associated urinary tract infection and surgical-site infection, which were collected during the point prevalence survey of HAIs in European acute-care hospitals between 2011 and 2012.ResultsWe estimated 478,222 (95% uncertainty interval (UI): 421,350-537,787) cases for Germany, resulting in 16,245 (95% UI: 10,863-22,756) attributable deaths and 248,920 (95% UI: 178,693-336,239) DALYs. Despite the fact that Germany has a relatively low hospital prevalence of HAIs compared with the European Union/European Economic Area (EU/EEA) average, the burden of HAIs in Germany (308.2 DALYs/100,000 population; 95% UI: 221.2-416.3) was higher than the EU/EEA average (290.0 DALYs/100,000 population; 95% UI: 214.9-376.9). Our methodology is applicable to other countries in or outside of the EU/EEA. An R package is available from https://CRAN.R-project.org/package=BHAI.ConclusionThis is the first study to estimate the burden of HAIs in DALYs for Germany. The large number of hospital beds may be a contributing factor for a relatively high burden of HAIs in Germany. Further focus on infection prevention control, paired with reduction of avoidable hospital stays, is needed to reduce the burden of HAIs in Germany.

Antibiotic consumption in Germany: first data of a newly implemented web-based tool for local and national surveillance.

Objectives: The features of a newly established, web-based surveillance system for hospital antibiotic consumption are described and data on broad-spectrum antibiotic use in German acute care hospitals are presented. Methods: The watch- and reserve-group antibiotics, two categories of antibiotics derived from the WHO Essential Medicines List comprising key agents for antimicrobial stewardship, were used as a framework for data analysis. The median antibiotic consumption densities (ACDs; DDD/100 patient days) for the years 2015/16 based on data from 137 acute care hospitals have been calculated for whole facilities, ICUs and medical and surgical departments, stratified by type of care. Results: The new web-based system provides real-time surveillance at unit and facility levels, accessible to all relevant stakeholders. User-defined reports are available via an interactive database, various report types support different approaches to analysis, and different complementing quantification measures of antimicrobial consumption are available. Watch- and reserve-group antibiotics accounted for 42% and 2% of total antibiotic use, respectively. Surgical services presented with considerably lower median ACDs of the watch-group antibiotics compared with medical services. Tertiary care hospitals exhibited higher ACDs of the reserve-group antibiotics and carbapenems than primary/secondary care hospitals, while the ACDs of the watch-group antibiotics as a whole did not differ significantly. Comparing the proportional use with other European countries revealed a relatively high use of the watch-group, ranking beyond the 75th percentile. Conclusions: Because of its particular features the new web-based surveillance system is a valuable tool for antimicrobial stewardship. The WHO categories of watch- and reserve-group antibiotics proved to be a useful framework for the analysis of hospital antibiotic consumption data.

Healthcare-associated pneumonia in acute care hospitals in European Union/European Economic Area countries: an analysis of data from a point prevalence survey, 2011 to 2012.

An aim of the ECDC point prevalence survey (PPS) in European Union/European Economic Area acute care hospitals was to acquire standardised healthcare-associated infections (HAI) data. We analysed one of the most common HAIs in the ECDC PPS, healthcare-associated pneumonia (HAP). Standardised HAI case definitions were provided and countries were advised to recruit nationally representative subsets of hospitals. We calculated 95% confidence intervals (CIs) around prevalence estimates and adjusted for clustering at hospital level. Of 231,459 patients in the survey, 2,902 (1.3%; 95% CI: 1.2-1.3) fulfilled the case definition for a HAP. HAPs were most frequent in intensive care units (8.1%; 95% CI: 7.4-8.9) and among patients intubated on the day of the survey (15%; 95% CI: 14-17; n = 737 with HAP). The most frequently reported microorganism was Pseudomonas aeruginosa (17% of 1,403 isolates), followed by Staphylococcus aureus (12%) and Klebsiella spp. (12%). Antimicrobial resistance was common among isolated microorganisms. The most frequently prescribed antimicrobial group was penicillins, including combinations with beta-lactamase inhibitors. HAPs occur regularly among intubated and non-intubated patients, with marked differences between medical specialities. HAPs remain a priority for preventive interventions, including surveillance. Our data provide a reference for future prevalence of HAPs at various settings.

Carbapenem non-susceptibility of Klebsiella pneumoniae isolates in hospitals from 2011 to 2016, data from the German Antimicrobial Resistance Surveillance (ARS).

Background: Carbapenem resistance in Klebsiella pneumoniae is of significant public health concern and recently spread across several countries. We investigated the extent of carbapenem non-susceptibility in K. pneumoniae isolates in Germany. Methods: We analysed 2011-2016 data from the German Antimicrobial Resistance Surveillance (ARS) System, which contains routine data of antimicrobial susceptibility testing from voluntarily participating German laboratories. Klebsiella pneumoniae isolates tested resistant or intermediate against an antibiotic were classified as non-susceptible. Results: We included 154,734 isolates from 655 hospitals in the analysis. Carbapenem non-susceptibility in K. pneumoniae isolates was low in Germany 0.63% (95% CI 0.51-0.76%). However, in continuously participating hospitals the number of K. pneumoniae isolates almost doubled and we found evidence for a slowly increasing trend for non-susceptibility (OR = 1.20 per year, 95% CI 1.09-1.33, p < 0.001). Carbapenem non-susceptibility was highest among isolates from patients aged 20-39 in men but not in women. Moreover, carbapenem non-susceptibility was more frequently reported for isolates from tertiary care, specialist care, and prevention and rehabilitation care hospitals as well as from intensive care units. Co-resistance of carbapenem non-susceptible isolates against antibiotics such as tigecycline, gentamicin, and co-trimoxazole was common. Co-resistance against colistin was 13.3% (95% CI 9.8-17.9%) in carbapenem non-susceptible isolates. Conclusion: Carbapenem non-susceptibility in K. pneumoniae isolates in Germany is still low. However, it is slowly increasing and in the light of the strong increase of K. pneumoniae isolates over the last year this poses a significant challenge to public health. Continued surveillance to closely monitor trends as well as infection control and antibiotic stewardship activities are necessary to preserve treatment options.

[Current aspects of the definition and diagnosis of sepsis and antibiotic resistance]. / Aktuelle Aspekte zur Definition und Diagnostik der Sepsis und Antibiotikaresistenz.

Hospital mortality of patients with secondary sepsis remains high at around 40%. Because of the methodological deficiencies of the definitions used so far, valid epidemiological data on secondary sepsis that allow for national and international comparisons are lacking. Since 2016, new clinical diagnostic tools that are also suitable for sepsis screening outside of intensive care units have been available. To counteract the high mortality of nosocomial sepsis, new approaches to the early identification of at-risk patients are needed. An adequate blood culture sampling rate and a high preanalytical quality should be established as a basis for quality assurance, especially in the field of nosocomial bloodstream infections; otherwise, there is a risk of surveillance bias. Data from laboratory-based antibiotic resistance surveillance on MRSA in blood culture isolates have shown a downward trend over the last 4 years. In Gram-negative pathogens, a relatively stable resistance situation has been observed over this period for many of the pathogen-antibiotic combinations.

[Global and national strategies against antibiotic resistance]. / Globale und nationale Strategien gegen Antibiotikaresistenzen.

Antimicrobial resistance (AMR) is increasingly perceived as a global health problem. To tackle AMR effectively, a multisectoral one health approach is needed. We present some of the initiatives and activities at the national and global level that target the AMR challenge. The Global Action Plan on AMR, which has been developed by the World Health Organization (WHO), in close collaboration with the Food and Agriculture Organization of the United Nations (FAO) and the World Organisation for Animal Health (OIE) is considered a blueprint to combat AMR. Member states endorsed the action plan during the World Health Assembly 2015 and committed themselves to develop national action plans on AMR. The German Antibiotic Resistance Strategy (DART 2020) is based on the main objectives of the global action plan and was revised and published in 2015. Several examples of the implementation of DART 2020 are outlined here.

The zoonotic potential of Clostridium difficile from small companion animals and their owners.

BACKGROUND: Clostridium difficile infections (CDI) in humans range from asymptomatic carriage to life-threatening intestinal disease. Findings on C. difficile in various animal species and an overlap in ribotypes (RTs) suggest potential zoonotic transmission. However, the impact of animals for human CDI remains unclear. METHODS: In a large-scale survey we collected 1,447 fecal samples to determine the occurrence of C. difficile in small companion animals (dogs and cats) and their owners and to assess potential epidemiological links within the community. The Germany-wide survey was conducted from July 2012-August 2013. PCR ribotyping, Multilocus VNTR Analysis (MLVA) and PCR detection of toxin genes were used to characterize isolated C. difficile strains. A database was defined and logistic regression used to identify putative factors associated with fecal shedding of C. difficile. RESULTS: In total, 1,418 samples met the inclusion criteria. The isolation rates for small companion animals and their owners within the community were similarly low with 3.0% (25/840) and 2.9% (17/578), respectively. PCR ribotyping revealed eight and twelve different RTs in animals and humans, respectively, whereas three RTs were isolated in both, humans and animals. RT 014/0, a well-known human hospital-associated lineage, was predominantly detected in animal samples. Moreover, the potentially highly pathogenic RTs 027 and 078 were isolated from dogs. Even though, C. difficile did not occur simultaneously in animals and humans sharing the same household. The results of the epidemiological analysis of factors associated with fecal shedding of C. difficile support the hypothesis of a zoonotic potential. CONCLUSIONS: Molecular characterization and epidemiological analysis revealed that the zoonotic risk for C. difficile associated with dogs and cats within the community is low but cannot be excluded.

Decline in the proportion of methicillin resistance among Staphylococcus aureus isolates from non-invasive samples and in outpatient settings, and changes in the co-resistance profiles: an analysis of data collected within the Antimicrobial Resistance Surveillance Network, Germany 2010 to 2015.

BACKGROUND: Recent analysis of trends of non-invasive infections with methicillin resistant Staphylococcus aureus (MRSA), of trends of MRSA infections in outpatient settings and of co-resistance profiles of MRSA isolates are scarce or lacking in Germany. METHODS: We analysed data from the Antimicrobial Resistance Surveillance Network (ARS). We included in the analysis the first isolate of S. aureus per patient and year, which had a valid test result for oxacillin resistance and which was not a screening sample. We limited the analysis to isolates from facilities, which contributed to ARS for all six years between 2010 and 2015. We compared the proportion of methicillin resistance among S. aureus isolates by calendar year using Chi-square and Fisher's exact test. We corrected for multiple testing using the Bonferroni correction. We stratified the analysis by sample type including various non-invasive sample types and by type of care (e.g. hospital versus outpatient clinic). We also analysed the non-susceptibility of MRSA to selected antibiotics. RESULTS: The analysis included 148,561 S. aureus isolates. The distribution of these isolates by sex, age, region, sample type, clinical speciality and type of care remained relatively stable over the six years analysed. The proportion of MRSA among S. aureus isolates decreased continuously from 16% in 2010 to 10% in 2015. This decrease was seen for all types of care and for the majority of sample types, including the outpatient clinic (12 to 8%), as well as blood culture (19 to 9%), urine samples (25 to 15%), swabs (14 to 9%), respiratory samples (22 to 11%) and lesions (15 to 10%). The non-susceptibility of MRSA isolates to tobramycin (47 to 32%), ciprofloxacin (95 to 89%), moxifloxacin (94 to 84%), clindamycin (80 to 71%) and erythromycin (81 to 72%) declined markedly, but it increased for tetracyclines (6 to 9%) and gentamicin (3 to 6%). Non-susceptibility of MRSA to linezolid, teicoplanin, tigecycline and vancomycin remained rare. CONCLUSION: This analysis indicates that the incidence of MRSA infections declined in a variety of settings in Germany between 2010 and 2015 and that the co-resistance profiles of MRSA isolates changed markedly.

Burden of Six Healthcare-Associated Infections on European Population Health: Estimating Incidence-Based Disability-Adjusted Life Years through a Population Prevalence-Based Modelling Study.

BACKGROUND: Estimating the burden of healthcare-associated infections (HAIs) compared to other communicable diseases is an ongoing challenge given the need for good quality data on the incidence of these infections and the involved comorbidities. Based on the methodology of the Burden of Communicable Diseases in Europe (BCoDE) project and 2011-2012 data from the European Centre for Disease Prevention and Control (ECDC) point prevalence survey (PPS) of HAIs and antimicrobial use in European acute care hospitals, we estimated the burden of six common HAIs. METHODS AND FINDINGS: The included HAIs were healthcare-associated pneumonia (HAP), healthcare-associated urinary tract infection (HA UTI), surgical site infection (SSI), healthcare-associated Clostridium difficile infection (HA CDI), healthcare-associated neonatal sepsis, and healthcare-associated primary bloodstream infection (HA primary BSI). The burden of these HAIs was measured in disability-adjusted life years (DALYs). Evidence relating to the disease progression pathway of each type of HAI was collected through systematic literature reviews, in order to estimate the risks attributable to HAIs. For each of the six HAIs, gender and age group prevalence from the ECDC PPS was converted into incidence rates by applying the Rhame and Sudderth formula. We adjusted for reduced life expectancy within the hospital population using three severity groups based on McCabe score data from the ECDC PPS. We estimated that 2,609,911 new cases of HAI occur every year in the European Union and European Economic Area (EU/EEA). The cumulative burden of the six HAIs was estimated at 501 DALYs per 100,000 general population each year in EU/EEA. HAP and HA primary BSI were associated with the highest burden and represented more than 60% of the total burden, with 169 and 145 DALYs per 100,000 total population, respectively. HA UTI, SSI, HA CDI, and HA primary BSI ranked as the third to sixth syndromes in terms of burden of disease. HAP and HA primary BSI were associated with the highest burden because of their high severity. The cumulative burden of the six HAIs was higher than the total burden of all other 32 communicable diseases included in the BCoDE 2009-2013 study. The main limitations of the study are the variability in the parameter estimates, in particular the disease models' case fatalities, and the use of the Rhame and Sudderth formula for estimating incident number of cases from prevalence data. CONCLUSIONS: We estimated the EU/EEA burden of HAIs in DALYs in 2011-2012 using a transparent and evidence-based approach that allows for combining estimates of morbidity and of mortality in order to compare with other diseases and to inform a comprehensive ranking suitable for prioritization. Our results highlight the high burden of HAIs and the need for increased efforts for their prevention and control. Furthermore, our model should allow for estimations of the potential benefit of preventive measures on the burden of HAIs in the EU/EEA.

Contamination during production of heater-cooler units by Mycobacterium chimaera potential cause for invasive cardiovascular infections: results of an outbreak investigation in Germany, April 2015 to February 2016.

Invasive infections with Mycobacterium chimaera were reported in patients with previous open chest surgery and exposure to contaminated heater-cooler units (HCUs). We present results of the surveillance of clinical cases and of contaminated HCUs as well as environmental investigations in Germany up until February 2016. Clinical infections occurred in five male German cases over 50 years of age (range 53-80). Cases had been exposed to HCUs from one single manufacturer during open chest surgery up to five years prior to onset of symptoms. During environmental investigations, M. chimaera was detected in samples from used HCUs from three different countries and samples from new HCUs as well as in the environment at the manufacturing site of one manufacturer in Germany. Our investigation suggests that at least some of the M. chimaera infections may have been caused by contamination of HCUs at manufacturing site. We recommend that until sustainable measures for safe use of HCUs in operation theatres are implemented, users continue to adhere to instructions for use of HCUs and Field Safety Notices issued by the manufacturer, implement local monitoring for bacterial contamination and continuously check the websites of national and European authorities for current recommendations for the safe operation of HCUs.