“Nightmare bacteria” that have become increasingly resistant to even the strongest antibiotics infected patients in 4 percent of U.S. hospitals in the first half of 2012 and in 18 percent of specialty hospitals, public health officials said on Tuesday.

“Our strongest antibiotics don’t work and patients are left with potentially untreatable infections,” Dr. Tom Frieden, director of the Centers for Disease Control and Prevention, said in a statement before an afternoon news conference. He said doctors, hospitals and public health officials must work together now to “stop these infections from spreading.”

Over the past decade more and more hospitalized patients have been incurably infected with the bug, Carbapenem-Resistant Enterobacteriaceae (CRE), which kills up to half of patients who get bloodstream infections from them, according to a new CDC report.

The bacteria belong to the Enterobacteriaceae family, which includes more than 70 species that normally live in the water, soil and human digestive system, such as the well-known E. coli. Over the years, some Enterobacteriaceae have become resistant to all or almost all antibiotics, including last-resort drugs known as carbapenems.

Over the past decade, the percentage of Enterobacteriaceae that are resistant to these last-ditch antibiotics rose by 400 percent. One type of CRE, a form of Klebsiella pneumoniae, has increased sevenfold in the last decade.

– 360 Experiment