Background: Acinetobactor baumanii, which is one of the species of highly resistant ESKAPE pathogens, is a major cause of nosocomial infections and high mortality rates. Evaluation of risk factors for such resistant infections will aid surveillance, diagnostic initiatives and can be crucial in early and appropriate antibiotic therapy.

Objectives: This study aimed to identify the risk factors in patients with resistant A. baumannii infection wrt controls.

Methods: Prospective or retrospective cohort and case-control studies reporting the risk factors for resistant A. baumannii infection were collected through data sources, MEDLINE/PubMed, OVID/Embase and Web of Science. Studies published in the English language were included while animal studies were excluded. The Newcastle-Ottawa Scale was used to assess the quality of studies. Odds ratio of developing antibiotic resistance in patients with A. baumannii infection was pooled using a random effect model.

Results: The results are based on 38 studies with 60878 participants (6394 cases and 54484 controls). A total of 28, 14, 25 and 11 risk factors were identified for multi-drug, extensive-drug (XDR) and carbapenem resistant-A. baumannii infections respectively.

In multidrug resistant-A. baumannii infection group, exposure of carbapenem [OR 5.51], tracheostomy [OR 5.01] and urinary catheter [OR 4.57] were identified with maximal pool odd’s ratio. While previous use of amikacin [OR 4.94], carbapenem [OR 4.91] and pneumonia [OR 4.71] were foremost factors associated with developing carbapenem resistance in A. baumannii infection.

Further analysis revealed, mechanical ventilation [OR 7.21], ICU stay [OR 5.88] and bedridden [OR 4.18] as the most significant factors for XDR-A. baumannii infections.

Conclusion:

The exposure of carbapenem, amikacin (previous) and mechanical ventilation were the most significant risk factors for multidrug, extensive-drug and carbapenem resistance in patients with A. baumannii infection respectively. These findings provide guidance to control and prevent resistant infections by identifying the patients at higher risk of developing resistance.