Acquisition and clearance of multidrug resistant Acinetobacter baumannii on healthy young adults concurrently burned in a dust explosion in Taiwan: the implication for antimicrobial stewardship

Abstract

BackgroundInformation is limited about the effect of restricted carbapenem use on clearance of multi-drug resistant Acinetobacter baumannii (MDRAB). We sought to determine the time effect of antibiotic exposure on multi-drug resistant Acinetobacter baumannii (MDRAB) acquisition and clearance.MethodsWe conducted a retrospective observational study at the intensive care units of a tertiary medical center. Forty-two of a cohort of previously healthy young adults who were concurrently burned by a dust explosion was included. Cases consisted of those from whom MDRAB was isolated during hospitalization. Controls consisted of patients from whom MDRAB was not isolated in the same period. Use of antimicrobial agents was compared based on days of therapy per 1,000 patient-days (DOT/1,000PD). A 2-state Markov multi-state model was used to estimate the risk of acquisition and clearance of MDRAB.ResultsMDRAB was discovered in 9/42 (21.4%) individuals. The cases had significantly higher use of carbapenem (652 DOT/1,000PD vs. 385 DOT/1,000PD, P < 0.001) before MDRAB isolation. For the cases, clearance of MDRAB was associated with lower use of carbapenem (469 DOT/1,000PD vs. 708 DOT/1,000PD, P = 0.003) and higher use of non-carbapenem beta-lactam (612 DOT/1,000PD vs. 246 DOT/1,000PD, P <0.001). In multi-state model, each additional DOT of carbapenem increased the hazard of acquiring MDRAB (hazard ratio (HR), 1.08; 95% confidence interval (CI) 1.01–1.16) and each additional DOT of non-carbapenem beta-lactam increased the protection of clearing MDRAB (HR, 1.25; 95% CI 1.07–1.46).ConclusionsBoth acquisition and clearance of MDRAB were related to antibiotic exposure in a homogeneous population. Our findings suggest that early discontinuation of carbapenem could be an effective measure in antibiotic stewardship for the control of MDRAB spreading.

Trends in microbial profile of burn patients following an event of dust explosion at a tertiary medical center

“…More information might be provided if molecular epidemiological surveillance was available. However, the overall data from our study showed that the incidence of A. baumannii isolates resistant to carbapenem was relatively low, and the result was similar to the incidence of CRABs (21%) reported by two similar groups, but treated in different hospitals [23,24]. Apart from CRAB, the resistance rates for other GNB were also quite low, such as carbapenem-resistant Enterobacteriaceae (0.3-2.4%) and pandrug-resistant P. aeruginosa (0.3%).…”

“…Recently one study showed that the overwhelming majority of bloodstream pathogens were GNB isolates typically isolated within 2 weeks after the burn. During 15-28 days after burn, A. baumannii was the most common causative pathogen, while Chryseobacterium spp., S. maltophilia, and R. mannitolilytica were most frequently isolated early (mean: 14.5 days) after the burn [24]. The proportion of the overall microbial isolates in this study showed a significant change in trend over time; in particular, hospitalization for more than 14 days (OR 4.5-9.8, p < 0.001).…”

Modifiable risk factors for multidrug‐resistant Gram‐negative infection in critically ill burn patients: a systematic review and meta‐analysis

“…Studies were published between 1994 and 2017 and combined data spanning from 1990 to 2015. The highest number of contributions came from France (two) and Turkey (two), while one study each was carried out in Australia, Brazil, Canada, Germany, Singapore, Spain and Taiwan . Studies ran for a median of 15 months (interquartile range 12–24) and analysed a total of 289 cases from a cohort of 2221 patients.…”

“…Two (18%) studies included patients from an ICU only, two (18%) from a burn ICU and seven (64%) combined data on ICU patients with patients from the burn ward . Seven (64%) studies focused exclusively on A. baumannii , two (18%) on P. aeruginosa , one (9%) study on K. pneumoniae and one (9%) analysed Gram‐negative bacteria collectively . Five (45%) studies used molecular typing to identify bacterial clones .…”

“…We also considered carbapenem resistance in A. baumannii or P. aeruginosa to be MDR where a study failed to list in detail the full resistance profile. We combined the terms colonization and infection because in the literature they are often used interchangeably in this patient population . This is because the usual physiological response to a burn involves elevated body temperature and inflammatory markers, thus making it difficult to distinguish between the two states.…”