Retrospective analysis ofAcinetobacter baumanniibacteraemia risk factors, complications, and mortality in a tertiary university hospital in Saudi Arabia

Introduction. Acinetobacter baumannii is a nosocomial pathogen of which many isolates are multidrug resistant. A. baumannii is a major cause of healthcare-acquired infections in patients who are critically ill, and A. baumannii bacteraemia (ABB) is associated with high mortality. Several factors are known to play a role in A. baumannii transmission and the emergence of resistance. Aim. This study aimed to retrospectively analyse ABB cases in Saudi Arabia, where little is known about the prevalence, risk factors, clinical disease, treatment outcomes, and mortality associated with this infection. Methods. A retrospective chart review was performed from January 1, 2015, until December 31, 2022, to identify all patients 14 years and above with ABB. Demographic and clinical data, as well as results from laboratory analyses, were collected from patients’ electronic charts. Statistical analyses were performed on the data to identify factors associated with 90-day mortality. Results. In total, 112 ABB cases were identified with a mean age of 58.0 years, of which 66.1% were males. Of these cases, 71 (63.4%) died. The factors that were found to be associated with 90-day mortality were the Charlson comorbidity score, Pitt bacteraemia score, quick Sequential Organ Failure Assessment (qSOFA) score (p < 0.001 for each), hospital ward (p < 0.02), short duration of antibiotic treatment (p < 0.01), and higher age (p < 0.05). The most common source of infection was Central Line-associated Bloodstream Infection in 52.7%. Also associated with mortality were inappropriate antimicrobial therapy (p < 0.02) and empirical use of colistin (p < 0.05). In many patients, ABB was caused by carbapenem-resistant A. baumannii (CRAB) (69.6%), and 74.4% of those patients died. Conclusion. CRAB is a growing threat in hospitals in Saudi Arabia especially in the critical care setting and carries a very high risk of mortality. Future studies should focus on novel ways of preventing CRAB infections and on the assessment of promising new antimicrobials such as cefiderocol or sulbactam-durlobactam and other treatment options such as bacteriophages.