Nosocomial infections due to Acinetobacter baumannii in a neurosurgery ICU.

Invasive infections caused by Acinetobacter baumannii in a post-operative neurosurgery ICU were studied. Sixty one patients admitted during a span of 11 months were culture positive for acinetobacter species from blood and/or CSF samples. They were followed up prospectively for evidence of infection and clinical outcome. 40 cases had clinical evidence of infection due to acinetobacter species while in 21 patients, the isolation of the organism was considered a contaminant. Acinetobacter baumannii was the most common organism associated with invasive infections. Respiratory tract was found to be the most common primary source of infection in patients with bacteraemia or meningitis. The age, sex and pre-operative hospital stay were not significantly different in the two groups (p>0.05), while post-operative hospital stay and mortality was significantly higher in patients with invasive infection (p<0.05). Acinetobacter baumannii was isolated from multiple sites (p<0.05) and repeatedly from the same site (p<0.001) in a significantly higher number of patients with invasive infections. Mortality was high in the patients infected with Acinetobacter baumannii. Even amongst the infected group, the patient shaving meningitis showed a higher mortality as compared to the patients having bacteraemia.