Four patients in an intensive-care unit at University of Maryland Medical Center have been isolated after lab tests showed that they have a relatively uncommon bacterial infection that is resistant to antibiotics.
Doctors identified the bacterium as Acinetobacter baumannii, known to attack wounded military personnel and hospital patients with weakened immune systems.
The isolated patients at the hospital have a treatment team assigned to them, members of which wear gowns and gloves, and the hospital has minimized risks that the infection might spread to its nine other intensive-care units, said Dr. Harold Standiford, medical director of infection control.
Standiford said the hospital acted after routine lab tests showed that one intensive-care patient was infected late last month.
Dr. David Blythe, a state epidemiologist, reviewed the hospital's plans after they were implemented Jan. 4.
"We want to keep this very well walled off so our other patients are safe," Standiford said.
Unlike MRSA, another antibiotic-resistant bacterium that can migrate from hospital wards to the general population, A. baumannii does "not hit healthy individuals," he said.
But the bacterium is capable of causing the deaths of people who are very sick or frail.
Three patients who had been in the same UM Medical Center intensive-care unit for several weeks have died in the two weeks since the bacterium was discovered, but Standiford said doctors might never know whether A. baumannii contributed to the deaths.
About 102 military personnel wounded in Afghanistan and Iraq were infected with the bacterium at Landstuhl Regional Medical Center in Germany and at Water Reed Army Medical Center between Jan. 1, 2002, and Aug. 31, 2004, according to a report from the federal Centers for Disease Control and Prevention.
Cases also have been reported over the years in hospital intensive-care units in the United States and Europe.
"The high level of antimicrobial resistance is a challenge to clinicians treating A. baumannii infections," the report said.
Dr. John Bartlett, an infectious-disease expert at the Johns Hopkins School of Medicine, said A. baumannii has become an increasing problem in hospitals, especially in infectious-disease units, where many patients are severely ill.
"We've had it at Hopkins, and I think most hospitals have had it," Bartlett said.
The organism has become resistant to many antibiotics and, as a result, has become extremely hard to treat, he said.
When patients have died, it is often hard to determine whether A. baumannii or their underlying disease was implicated.
"When these people get infected, their kidneys are already failing, their livers are failing, they're on ventilation. You sort of say this is the last straw," Bartlett said.
Sun reporter Jonathan Bor contributed to this article.