Nosocomial-acquired Non-fermenting Gram-negative Bacilli: Impact on Morbidity and Mortality in a Brazilian University Hospital

Aims: To investigate non-fermenting Gram-negative bacilli (NFGNB), Acinetobacter baumannii and Pseudomonas aeruginosa, recovered from clinical isolates and surveillance cultures, accessing their role on morbidity and hospital mortality.

Study Design: This observational case-control study was conducted in the Hospital of the Universidade Federal de Minas Gerais, between March 2012 and September 2013.

Methodology: We included 102 patients categorized by 51 study group (those infected or colonized by multidrug resistant NFGNB, mainly A. baumannii) and 51 controls (patients colonized or infected by other multiresistant Gram-negative bacteria). Demographic (gender and age) and clinical data (diagnosis of sepsis, antimicrobial intake during hospitalization, among others) were compared between groups. Hospital mortality and length of hospital stay were investigated.

Results: The average age was of 61 years (± 15) in the case group and of 54 (± 18) in the control group (P= .004). Male represented 54.9% of the case group and 43.1% of the control (P= .32). It was observed higher mortality rates in the case group (33.3% vs. 9.8%; P=.008), which also had longer periods of hospital stay (57.5 days vs. 29.9; P< .001), longer antimicrobials intake (28.7 days vs. 15; P<.001) and more complex treatment regimens than the control group. Multivariate analysis showed that NFGNB colonization was associated with mortality during hospital stay (OR 4.60; CI 95% [1.54 to 13.69]).

Conclusion: Recovery of NFGNB seems to be associated with poor outcomes in hospitalized adult patients, even when the analysis is adjusted for other potential risk factors. Other studies involving larger samples of patients are necessary in an attempt to better understand the meaning of these preliminary findings.