Infection control and risk factors for acquisition of carbapenemase-producing enterobacteriaceae. A 5 year (2011-2016) case-control study.

Background: Carbapenemase-producing enterobacteriaceae (CPE) are a major threat for severely ill patients. However, only limited data on the epidemiology and on evidence-based infection prevention and control measures are available. The aim of this study was to investigate the epidemiology of patients with CPE, characterizing the CPE isolates by their resistance mechanisms and genetic similarity, to explore risk factors for their acquisition, and to evaluate the effectiveness of the current CPE infection control measures. Methods: A retrospective case-control study was performed using data from 2011 to 2016 in a 1800-bed academic hospital in Central Europe, where risk-based screening at patients´ admission is performed. Carbapenem resistance mechanisms of all carbapenem resistant enterobacteriaceae from patients admitted during this period were investigated. Clinical data of the CPE-positive patients were analysed and compared to a matched control group (case-control ratio of 1:3). We performed univariate and multivariate statistical analysis to identify risk factors for CPE acquisition. Results: Of 621,623 admitted patients in the study period, 75 patients with carriage of carbapenem resistant enterobacteriaceae were included (0.12/1000 admittances). Carbapenemase-encoding genes were detected in 77.3% (58/75) of patients with carbapenem-resistant enterobacteriaceae. The enzyme blaOXA-48 was found in 34.5% (20/58), blaKPC in 29.3% (17/58), blaNDM enzymes in 20.7% (12/58) and blaVIM in 8.6% (5/58) of the isolates. The overall mortality among CPE patients was 25.9% (15/58) and attributable mortality of CPE was 53.3% (8/15). Multivariate analysis revealed four risk factors to be independent predictors of CPE carriage: the length of hospital admission > 20 days (AOR: 4.9, 95% CI: 1.4-15.5; P <  0.001), hospital admission within the previous year (AOR: 22.3, 95% CI: 3.9-88.4; P <  0.001), exposure to a healthcare facility in a country with high or unknown carbapenem-resistant enterobacteriaceae prevalence 3 months before admission (AOR: 11.8, 95% CI: 2.2-63.2; P <  0.01) and the use of antibiotics longer than 10 days (AOR: 5.2, 95% CI: 1.4-35.9; P <  0.05). The current risk-based screening strategy at hospital admission could not identify 37 (63.8%) of the 58 CPE-positive patients. Epidemiological investigation and genotyping revealed that no outbreaks due to CPE occurred during this period. Conclusion: Overall, the CPE carriage rate in patients was very low, the attributable mortality, however, is alarming (53%). BlaOXA-48 and blaKPC were the main cause of carbapenem resistance in enterobacteriaceae. Although the strict application of standard infection control measures was effective for prevention of outbreaks in this setting, an enlarged risk based targeted screening strategy has to be implemented.

Bacterial Extracellular DNA Production Is Associated with Outcome of Prosthetic Joint Infections.

In a retrospective study the association of the production of extracellular DNA (eDNA) in biofilms of clinical staphylococcal isolates from 60 patients with prosthetic joint infection (PJI) and the clinical outcome were investigated. Data from a previous study on eDNA production determined in 24-hour biofilms of staphylococcal isolates (Staphylococcus aureus n=30, Staphylococcus epidermidis n=30) was correlated with the patients' clinical outcome after 3 and 12 months. Statistical analysis was performed using either the Spearman's rank correlations test or the t-test. eDNA production of S. epidermidis in 24-hour biofilms correlated with the patients' outcome 'not cured' after 12 months. For S. aureus no such correlation was detected. Thus, eDNA may be a virulence factor of S. epidermidis. Quantification of eDNA production as a surrogate marker for biofilm formation might be a potential predictive marker for the management of PJI.

Molecular epidemiology of multidrug-resistant clinical isolates of Acinetobacter baumannii : A 10-year analysis in a large tertiary care university hospital in central Europe with international admissions.

BACKGROUND: Over the last 10 years, multidrug resistant Acinetobacter baumannii has been spreading worldwide as emerging microorganisms that negatively impact on the outcome of in-hospital patients. METHODS: Between 2007 and 2016, all isolates of patients of the Vienna General Hospital (VGH), tested positive for multidrug resistant Acinetobacter baumannii (MDR A. baumannii) strains, were investigated with respect to their genetic relationship. Patient medical histories were reviewed in order to collect discriminating factors related to MDR A. baumannii colonization or infection. RESULTS: A total of 79 isolates of 76 patients were obtained. For 44 of them (55.7%) the first diagnosis ward was an intensive care unit (ICU). A total of 10 genotype clusters were identified and 35 cases (44.3%) of in-hospital acquisition in our institution could be detected. Multidrug resistant Acinetobacter baumannii isolates were acquired before admission to our hospital in 44 cases (55.7%) and in 31 (70.5%) they belonged to patients who had previous exposure to the healthcare setting of high prevalence countries for MDR A. baumannii. CONCLUSION: Patients admitted to our hospital with a previous healthcare contact in a high prevalence country for multidrug resistant Acinetobacter baumannii should be screened before admission to high-risk wards. Isolation of these patients until microbiological results could reduce negative outcome in these wards.

A national point prevalence study on healthcare-associated infections and antimicrobial use in Austria.

BACKGROUND: The first point prevalence survey performed in Austria had the aim to assess the magnitude of healthcare-associated infections and antimicrobials use in the country. METHODS: A multicentre study was carried out from May until June 2012 in nine acute care hospitals with a mean bed number of 620. Data from 4321 patients' clinical charts were reviewed. RESULTS: The overall healthcare-associated infections prevalence was 6.2% (268/4321) with the highest rate in intensive care departments (20.9%; 49/234). In medical and surgical departments the healthcare-associated infections prevalence was 5.4% (95/1745) and 6.6% (105/1586), respectively. The most frequent healthcare-associated infections were: urinary tract infections (21.3%; 61/287), pneumonia (20.6%; 59/287) and surgical site infections (17.4%; 50/287). The most common isolated microorganisms were: Escherichia coli (14.8%; 26/176), Enterococcus species (13.1%; 23/176) and Pseudomonas aeruginosa (11.4%; 20/176). Thirty-three per cent (1425/4321) of the patients received antimicrobials because of community-acquired infections treatment (14.2%; 615/4321), healthcare-associated infections treatment (6.4%; 278/4321), and surgical (8.2%; 354/4321) and medical prophylaxis (3.2%; 138/4321). Surgical prophylaxis was the indication for 22.0% (394/1792) of the overall prescriptions and was prolonged for more than 1 day in 77.2% (304/394) of the cases. CONCLUSION: The national Austrian survey proved the feasibility of a nation-wide network of surveillance of both healthcare-associated infections and antimicrobial use that will be repeated in the future. Healthcare-associated infections and antimicrobial use have been confirmed to be a grave health problem. The excessive prolongation of perioperative prophylaxis in Austria needs to be limited.

Severe Clostridium difficile infection: incidence and risk factors at a tertiary care university hospital in Vienna, Austria.

BACKGROUND: Clostridium difficile infection (CDI) is the major cause of hospital-acquired bacterial diarrhoea. The incidence of CDI has been increasing in Canada, the US and Europe and severe cases are becoming more common. METHODS: A retrospective cohort study investigating all patients with an episode of CDI present at the Vienna University Hospital between 01 January 2012 and 31 December 2012 was conducted. All microbiologically confirmed C. difficile toxin positive cases were included, ribotyped and analysed regarding their clinical course. RESULTS: A total of 278 patients with CDI were recorded, with an overall CDI incidence of 5.23 per 10,000 patients-days. Around 84,5 % (235/278) of CDI cases would have been classified as severe CDI according to European Society of Clinical Microbiology and Infectious Diseases (ESCMID) if all criteria were used. According to Society for Healthcare Epidemiology of America and the Infectious Diseases Society of America (SHEA/IDSA) guidelines only 16.5 % (46/278) could be classified as severe; with a severe CDI incidence of 4.41 and 0.86 per 10,000 patient-days, respectively. Multivariate analysis showed only a co-morbidity index of ≥ 3 (p = 0.013) as independent risk factor for severe CDI. No link between ribotype 027 and severity or clustering was observed in our study population. CONCLUSIONS: Special attention in terms of restrictive antibiotic prescription should be given to patients having a Charlson co-morbidity ≥ 3 at the time of hospital admission. SHEA/IDSA guidelines were more accurate than ESCMID criteria in predicting severe CDI in our collective, of mostly severely ill patients, in a tertiary care hospital setting.

Factors associated with patient and health care system delay in diagnosis for tuberculosis in the province of Luanda, Angola.

BACKGROUND: Tuberculosis (TB) is still a great challenge to public health in sub-Saharan Africa. Most transmissions occur between the onset of coughing and initiation of treatment. Delay in diagnosis is significant to disease prognosis, thus early diagnosis and prompt effective therapy represent the key elements in controlling the disease. The objective of this study was to investigate the factors influencing the patient delay and the health system delay in TB diagnosis in Angola. METHODS: On a cross-sectional study, 385 TB patients who visited 21 DOTS clinics in Luanda were included consecutively. The time from the onset of symptoms to the first consultation of health providers (patients' delay) and the time from the first consultation to the date of diagnosis (health system's delay) were analysed. Bivariate and logistics regression were applied to analyse the risk factors of delays. RESULTS: The median total time elapsed from the onset of symptoms to diagnosis was 45 days (interquartile range [IQR]: 21-97 days). The median patient delay was 30 days (IQR: 14-60 days), and the median health care system delay was 7 days (IQR: 5-15 days). Primary education (AOR = 1.75; CI [95%] 1.06-2.88; p <0.029) and the health centre of the first contact differing from the DOTS centre (AOR = 1.66; CI [95%] 1.01-2.75; p <0.046) were independent risk factors for patient delay >4 weeks. Living in a suburban area (AOR = 2,32; CI [95%] 1.21-4.46; p = 0.011), having a waiting time in the centre >1 hour (AOR = 4.37; CI [95%] 1.72-11.14; p = 0.002) and the health centre of the first contact differening from the DOTS centre (AOR = 5.68; CI [95%] 2.72-11,83; p < 0,00001) were factors influencing the system delay. CONCLUSIONS: The results indicate that the delay is principally due to the time elapsed between the onset of symptoms and the first consultation. More efforts should be placed in ensuring the availability of essential resources and skills in all healthcare facilities other than the DOTS centres, especially those located in suburban areas.