According to a scientific review, A baumannii can be found in environmental sources such as soil, food, vegetables, meat and fish and may colonise the skin of healthy people at low density for a short time.
However infections can occur in hospitalised patients, particularly those who are already critically ill, report authors wrote.
Like with other superbugs such as MRSA and C. diff, patients of advanced age, with serious underlying diseases, immune suppression, major trauma or burn injuries are at risk.
Invasive procedures including indwelling catheters, mechanical ventilation support, extended hospital stay and previous administration of antibiotics are also associated with infections.
Surveillance has indicated that 30% of cases are multidrug resistant and rates of resistance to the antibiotic Carbapenem, the agent of choice, are increasing.
The effectiveness of the alternative treatment, Sulbactam, is decreasing but small clinical trials have indicated that Polymyxins are possibly alternatives.
Authors wrote: ‘This pathogen is associated with institutional outbreaks that are difficult to control. Potential common sources include contaminated environmental sites and medical equipment, and health-care personnel with skin colonisation.
‘Measures to address specific modes of transmission identified during an outbreak and strict adherence to a variety of infection control measures are typically required for the containment of an outbreak.’
Lancet Infectious Diseases (2008) 8:751-62