(ABC News) -- A new superbug is on the rise in U.S. hospitals, according to the U.S. Centers for Disease Control and Prevention. The family of germs, dubbed CRE for carbapenem-resistant Enterobacteriaceae, evades some the strongest antibiotics, making infections almost untreatable.
"Right now, these infections are limited to hospitals, but we know from history that bacteria that start in hospitals often find a way out into the community," said ABC News chief health and medical editor Dr. Richard Besser, who for seven years ran a CDC program aimed at promoting proper antibiotic use to curb antibiotic resistance. "That would be a nightmare scenario."
One in 25 acute-care facilities reported at least one case of hospital-acquired CRE last year, according to the CDC. Most of the infected patients, who tended to have multiple medical problems and weakened immune systems, were treated with colistin, an older antibiotic that can have toxic effects on the kidneys.
"For many patients, that's their only choice," Besser said. "And even with treatment, almost half of all patients who get this infection in their bloodstream die from it."
The CDC has urged hospitals, health care providers and patients to take steps to curb the spread of the dangerous superbug that include frequent hand-washing. The agency also recommends removing intravenous lines and catheters as early as possible to reduce the risk of infection.
"The goal of the campaign is to get this under control right now, before CRE has a chance to spread to more hospitals and out into the community," said Besser.
CRE isn't the only scary superbug. ABC News asked infectious disease experts which antibiotic-resistant bacteria pose the biggest threats at home and abroad.