Headlines about hospital superbugs have focussed overwhelmingly on bacteria called MRSA, for methicillin-resistant staphylococcus aureus (MRSA).
But a different pathogen, Acinetobacter baumannii, is an expanding threat and controlling outbreaks of it are proving extremely difficult, said the study, published in the British medical journal The Lancet.
Nearly a third of cases involving infection by A. baumannii have shown resistance to frontline antibiotics, it said, citing research data.
"Institutional outbreaks caused by multidrug resistant strains are a growing public health problem," said co-authors Drosos Karageorgopoulos and Matthew Falagas of the Alfa Institute of Biomedical Sciences in Athens.
According to a 2004 study of 24,000 US cases, 34 percent of patients whose bloodstream became infected by A. baumannii while in hospital eventually died, a figure that rose to 43 percent among those in intensive care, they said.
Urgent measures must be taken to prevent outbreaks in healthcare facilities, and to identify which drugs and drug combinations are the most effective in neutralising the bacteria, they warned.
A. baumannii rarely attacks healthy individuals, and is more frequently found among critically ill hospital patients.
Conditions which favor the superbug are advanced age, serious underlying diseases, weakened immune systems, along with major trauma and burns.
Patients who have undergone surgery or are fitted with catheters are also more vulnerable to infection, along with persons breathing with the help of mechanical ventilation.
Symptoms include pneumonia and bacteria in the blood, as well as infection of surgical sites and the urinary tract.
The new study reviews different options for controlling and treating infections.
Stricter hygiene practices -- sterilisation of reusable medical equipment, hand washing, limiting physical contact -- are essential, the researchers say.
They also review the panoply of antibiotics available.
Long regarded as the "agents of choice," a category of treatment called carbapenems has shown much higher rates of resistance in recent years.
Other antibiotic groups, polymyxins and minocyclines, have been shown to be more effective.