Role of place of acquisition and inappropriate empirical antibiotic therapy on the outcome of extended-spectrum β-lactamase-producing Enterobacteriaceae infections

Tacconelli E, Cataldo  MA, Mutters NT, Carrara E, Bartoloni A, Raglio A, Cauda R, Mantengoli E,  Luzzaro F, Pan A, Beccara LA, Pecile P, Tinelli M, Rossolini GM.

Int J Antimicrob Agents. 2019 Jul;54(1):49-54. doi: 10.1016/j.ijantimicag.2019.04.007. Epub 2019 Apr 12.

The impact of inappropriate empirical antibiotic therapy (IEAT) on  the outcome of severe infections due to extended-spectrum  β-lactamase-producing Enterobacteriaceae (ESBL-Ent) remains unclear.  Current evidence is limited by study design and lack of confounder  control. The main objective of this study was to define the outcome of  severe infections due to ESBL-Ent according to clinical parameters and  place of infection acquisition. Adult hospitalised patients with  ESBL-Ent infections were included in a 3-year multicentre prospective  study. Primary outcomes were IEAT rates and crude mortality of severe  infections, adjusted by place of acquisition [community-acquired  infection (CAI), healthcare-associated infection (HCAI) and  hospital-acquired infection (HAI)]. Among 729 patients, 519 (71.2%) were  diagnosed with HAI, 176 (24.1%) with HCAI and 34 (4.7%) with CAI.  Moreover, 32.9% of patients received IEAT; higher rates of IEAT were  observed in pneumonia (23%) and deep surgical site infections (19%).  HCAIs were more frequently associated with IEAT than HAIs (48.3% vs.  27.9%; OR = 1.7, 95% CI 1.2-2.4). The overall mortality rate for severe  infections (n = 264) was 12.1% and was significantly higher in HCAIs  (20%) than HAIs (10%) (RR = 2.3, 95% CI 1.01-5.3). IEAT significantly  increased the risk of mortality in bloodstream infections (RR = 8.3, 95%  CI 2-46.3). Rates of IEAT and overall mortality of ESBL-Ent severe  infections were higher in HCAIs than HAIs. Prompt diagnosis of patients  with severe HCAIs due to ESBL-Ent is essential since these infections  receive high rates of IEAT and significantly higher mortality than HAIs  [ClinicalTrials.gov Identifier: NCT00404625].

Keywords:  Community-acquired infection; ESBL; Extended-spectrum β-lactamase; Inappropriate antibiotic therapy.