Epidemiology and infection control of carbapenem resistant Acinetobacter baumannii and Klebsiella pneumoniae at a German university hospital: a retrospective study of 5 years (2015-2019)

Effect of Antimicrobial Stewardship 2018 on severe pneumonia with bacterial infection in paediatric intensive care units

OBJECTIVES

Antimicrobial Stewardship 2018 (ASP 18) in China emphasizes the hierarchical control of antimicrobial drugs and the management of physicians' prescribing authority, especially in children. The purpose of this study was to assess the effect of implementation of ASP 2018 on antibiotic consumption, resistance, and treatment outcomes in children with severe pneumonia from bacterial infections.

METHODS

A single center, retrospective study was conducted on 287 children with severe bacterial pneumonia, including 165 patients before intervention (May 2016-April 2018) and 122 patients after intervention (May 2018-April 2020). The antimicrobial resistance rates, antibiotic consumption, and clinical outcomes of the two periods were compared.

RESULTS

After the implementation of ASP 2018, Staphylococcus aureus (17.9%) became the predominant Gram-positive bacterium. The resistance of Streptococcus pneumoniae to clindamycin, erythromycin, and tetracycline was significantly reduced (P < 0.001), and Staphylococcus aureus to tetracycline also decreased (P = 0.034). In addition, Klebsiella pneumoniae (18.4%) replaced Pseudomonas aeruginosa (9.5%) as the most common Gram-negative bacterium. The resistance rates of Klebsiella pneumoniae to amoxicillin/clavulanic acid (AMC) and trimethoprim/sulfamethoxazole (SXT), and Acinetobacter baumannii to cefotaxime and SXT decreased significantly (P < 0.02). Total consumption (DDD/100 patient-days) of five antibiotics (cephalosporins, carbapenems, macrolides, antifungal agents, and linezolid) showed a decreasing trend, and the decrease in antifungal agents and linezolid was the most significant (27.4% and 25.6%, P < 0.001). The isolation rate of multidrug-resistant (MDR) strains decreased significantly from the highest, 16.8%, before intervention to 6.7% after intervention (P < 0.001).

CONCLUSION

Our data indicate that the implementation of antimicrobial management strategies has significantly reduced the consumption of antibiotics and the occurrence of antimicrobial resistance in children with severe bacterial pneumonia in PICU.

Epidemiology and infection control of vancomycin-resistant enterococci at a German university hospital: A three-year retrospective cohort study

Vancomycin-resistant enterococci (VRE) occur in hospitalized patients, causing both infection and colonization. In recent years, there has been an increase in VRE in German and other hospitals, raising the question of how to control this epidemic best. To better understand the specific epidemiology and to guide infection control, we conducted a retrospective cohort study analyzing all patients with VRE at Hannover Medical School, a tertiary university clinic in Germany that specializes in solid organ transplantation. Epidemiologic and clinical characteristics of patients with VRE from 2015-2017 were collected. Basic epidemiologic parameters, including VRE incidence and incidence density, were calculated. Independent risk factors for nosocomial VRE infection compared to colonization were assessed using a logistic regression model. There were 1,492 VRE cases corresponding to 822 individual patients. The incidence was 0.8 VRE cases per 100 cases. A total of 536 (35.9%) of the 1,492 VRE cases were acquired nosocomially. Of the 1,492 cases, 912 cases had VRE-positive samples (894 Enterococcus (E.) faecium and 18 E. faecalis) in our hospital laboratory and the remaining cases were known VRE carriers. The vanB-phenotype was observed in 369 of the 894 (41.3%) E. faecium isolates and in 6 of the 18 (33.3%) E. faecalis isolates. There was an increase over time in the vanB-phenotype proportion in E. faecium (2015: 63 of 171, 36.8%, 2016: 115 of 322, 35.7% and 2017: 191 of 401, 47.6%). A total of 107 cases had a VRE infection (7.2% of all VRE cases) according to the criteria of the German National Reference Center for Surveillance of Nosocomial Infections. The remaining cases were only colonized. Among other factors, leukocytopenia (<1,000/μL), the use of a central venous catheter and the visceral surgery medical specialty were independently associated with nosocomial VRE infection. VRE imposed a relevant and increasing infection control burden at our hospital. Nosocomial VRE infection was predominantly found in certain medical specialties, such as hematology and oncology and visceral surgery. Infection control efforts should focus on these highly affected patient groups/specialties.

Control of Healthcare-Associated Carbapenem-Resistant Acinetobacter baumannii by Enhancement of Infection Control Measures

Antimicrobial stewardship and infection control measures are equally important in the control of antimicrobial-resistant organisms. We conducted a retrospective analysis of the incidence rate of hospital-onset carbapenem-resistant Acinetobacter baumannii (CRAB) infection (per 1000 patient days) in the Queen Mary Hospital, a 1700-bed, university-affiliated teaching hospital, from period 1 (1 January 2007 to 31 December 2013) to period 2 (1 January 2014 to 31 December 2019), where enhanced infection control measures, including directly observed hand hygiene before meal and medication rounds to conscious patients, and the priority use of single room isolation, were implemented during period 2. This study aimed to investigate the association between enhanced infection control measures and changes in the trend in the incidence rate of hospital-onset CRAB infection. Antimicrobial consumption (defined daily dose per 1000 patient days) was monitored. Interrupted time series, in particular segmented Poisson regression, was used. The hospital-onset CRAB infection increased by 21.3% per year [relative risk (RR): 1.213, 95% confidence interval (CI): 1.162−1.266, p < 0.001], whereas the consumption of the extended spectrum betalactam-betalactamase inhibitor (BLBI) combination and cephalosporins increased by 11.2% per year (RR: 1.112, 95% CI: 1.102−1.122, p < 0.001) and 4.2% per year (RR: 1.042, 95% CI: 1.028−1.056, p < 0.001), respectively, in period 1. With enhanced infection control measures, the hospital-onset CRAB infection decreased by 9.8% per year (RR: 0.902, 95% CI: 0.854−0.953, p < 0.001), whereas the consumption of the extended spectrum BLBI combination and cephalosporins increased by 3.8% per year (RR: 1.038, 95% CI: 1.033−1.044, p < 0.001) and 7.6% per year (RR: 1.076, 95% CI: 1.056−1.097, p < 0.001), respectively, in period 2. The consumption of carbapenems increased by 8.4% per year (RR: 1.84, 95% CI: 1.073−1.094, p < 0.001) in both period 1 and period 2. The control of healthcare-associated CRAB could be achieved by infection control measures with an emphasis on directly observed hand hygiene, despite an increasing trend of antimicrobial consumption.