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

Abstract

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.

Keywords: antimicrobial consumption; carbapenem-resistant Acinetobacter baumannii; carbapenem-resistant Enterobacterales; directly observed hand hygiene; hand hygiene; healthcare-associated infection; infection control; multidrug-resistant Acinetobacter baumannii.

Figure 1

Antimicrobial-resistant organisms in Queen Mary Hospital from 2007 to 2019. CRAB, carbapenem-resistant Acinetobacter baumannii; CephRE, cephalosporin-resistant Enterobacterales; CRE, carbapenem-resistant Enterobacterales; MRAB, multidrug-resistant Acinetobacter baumannii. Remark: CRAB was defined as Acinetobacter baumannii which was non-susceptible (either resistant or intermediate) to either imipenem or meropenem being tested in our microbiology laboratory. MRAB was defined as Acinetobacter baumannii which was non-susceptible (either resistant or intermediate) to at least one agent in at least 3 antimicrobial classes of aminoglycosides, extended spectrum BLBI combination, carbapenems, cephalosporins, fluoroquinolones, and sulbactam [41]. CRE was defined as the microorganisms (E. coli, Klebsiella species, and Enterobacter species), under the order of Enterobacterales commonly cause infections in healthcare settings, non-susceptible (either resistant or intermediate) to either imipenem or meropenem [43]. CephRE was defined as the microorganisms (E. coli, Klebsiella species, and Enterobacter species) non-susceptible (either resistant or intermediate) to either cefepime, ceftazidime, or ceftriaxone in this study.

Figure 2

Hand hygiene compliance among healthcare workers in Queen Mary Hospital from 2007 to 2019. The numbers marked in the vertical bars represent the number of observed hand hygiene opportunities by infection control nurses. Non-mediated soap was used throughout the years of study.

Figure 3

Hospital-onset antimicrobial-resistant organisms in Queen Mary Hospital from 2007 to 2019. CRAB, carbapenem-resistant Acinetobacter baumannii; CephRE, cephalosporin-resistant Enterobacterales; CRE, carbapenem-resistant Enterobacterales; MRAB, multidrug-resistant Acinetobacter baumannii.

Figure 4

Antimicrobial consumption in Queen Mary Hospital before and after the enhancement of infection control measures. All, all antimicrobial agents; BLBI, extended spectrum betalactam-betalactamase inhibitor combination; Carbap, carbapenems; Ceph, cephalosporins; FQ; fluoroquinolones.