Acinetobacter baumannii Infection in Prior ICU Bed Occupants Is an Independent Risk Factor for Subsequent Cases of Ventilator-Associated Pneumonia

Objective. We aimed to evaluate risk factors for ventilator-associated pneumonia (VAP) due to Acinetobacter baumannii (AbVAP) in critically ill patients. Methods. This was a prospective observational study conducted in an intensive care unit (ICU) of a district hospital (6 beds). Consecutive patients were eligible for enrolment if they required mechanical ventilation for > 48 hours and hospitalization for > 72 hours. Clinical, microbiological, and laboratory parameters were assessed as risk factors for AbVAP by univariate and multivariate analysis. Results. 193 patients were included in the study. Overall, VAP incidence was 23.8% and AbVAP, 11.4%. Previous hospitalization of another patient with Acinetobacter baumannii infection was the only independent risk factor for AbVAP (OR (95% CI) 12.016 (2.282-19.521) P < 0.001). ICU stay (25 +/- 17 versus 12 +/- 9 P < 0.001), the incidence of other infections (OR (95% CI) 9.485 (1.640-10.466) P = 0.002) (urinary tract infection, catheter related infection, and bacteremia), or sepsis (OR (95% CI) 10.400 (3.749-10.466) P < 0.001) were significantly increased in patients with AbVAP compared to patients without VAP; no difference was found with respect to ICU mortality. Conclusion. ICU admission or the hospitalization of patients infected by Acinetobacter baumannii increases the risk of AbVAP by subsequent patients.