Slowly but surely, over the past decade a little strain of bacteria has been gaining steam. Known as carbapenem-resistant Enterobacteriaceae (or, because that long name is impossible to remember, CRE), this germ has spent years gaining resistance to basically every single antibiotic we’ve got. Recent reports of this “nightmare bacteria” have grabbed headlines, and there are reports of fatality rates as high as fifty percent. The CDC called a press conference to explain what they called a “critical health issue.” Basically, it’s bad, and the CDC is really worried.

It’s easy to pooh-pooh the CDC. The agency told you to get a flu shot, too; you didn’t, but you also didn’t get the flu. And what about that overhyped bird flu thing? And Hurricane Irene wasn’t bad at all! Why should you listen to them?

Well, fine, don’t listen to the CDC. But maybe listen to Maryn McKenna, who spends most of her time writing about nasty horrible things like MRSA and food poisoning. She wrote on Facebook: “The CDC usually falls over backward trying to be non-alarmist; so when they call something a “nightmare,” it’s good to listen.” And here she is, in Wired, summarizing the bug’s dangers:

The underlying risk here is that effectively untreatable CRE will spread out from hospitals and into the wider world, where it will become vastly more common and much harder to detect. That is not an unreasonable fear, given that the Enterobacteriaceae include incredibly common E. coli, which has already been found to be causing bladder infections bearing a slightly less dire form of multi-drug resistance, known as ESBL.

Or perhaps you should listen to Dr. Brad Spellberg, a researcher at the Harbor-UCLA Medical Center who specializes in infectious diseases. He told NPR:

We’re not talking about an iceberg that’s down the line. The ship has hit the iceberg. We’re taking on water. We already have people dying. Not only of CRE, but of untreatable CRE.

At CNN, they break down some of the numbers:

Each year, hospital-acquired infections sicken about 1.7 million and kill 99,000 people in the United States. While up to 50% of patients with CRE bloodstream infections die, similar antibiotic-susceptible bacteria kill about 20% of bloodstream-infected patients.

It’s true that the majority of the infected people are already in hospitals, which means that their immune systems are compromised already. But should the bacteria escape to the broader public, it could still be hugely dangerous.

If you’re ready to listen to the CDC, here’s what the agency’s director, Tom Frieden, said in the press conference:

CRE… pose a triple threat. First, they’re resistant to all or nearly all antibiotics. Even some of our last-resort drugs. Second, they have high mortality rates. They kill up to half of people who get serious infections with them. And third, they can spread their resistance to other bacteria. So one form of bacteria, for example, carbapenem-resistant Klebsiella, can spread the genes that destroy our last antibiotics to other bacteria, such as E. coli, and make E. coli resistant to those antibiotics also… We only have a limited window of opportunity.

The CDC has outlined some ways to prevent CRE from spreading. These are techniques like effective testing for the bug, grouping patients that have it together, requiring hospitals to declare that a patient has CRE when transferring to another hospital and cutting down on the use of the antibiotics that help make CRE so resistant. But whether or not this will work is still up in the air. McKenna explains:

But an important point is that none of this is required, and none of this is funded. When the Netherlands wanted to beat back the emergence of MRSA, that country passed laws requiring every hospital to test patients before letting them in the door. (That story is told in this book.) When Israel wanted to counter KPC, which was ripping through its hospitals after arriving from the US, it created a national task force and imposed mandatory national measures for detecting and confining the infection. (That program is described in this 2011 paper.) And hospitals are on their own in figuring out how to organize and pay for CRE control. There are no reimbursements, under Medicare, for infection-control as a hospital task; and as infection-prevention physician Eli Perencevich demonstrated two years ago, the National Institutes of Health is not funding resistance-countering research.

So while the CDC is trying to sound the alarm and get everybody moving to stop CRE, it’s unclear whether they’ll be able to.

More from Smithsonian.com:

Gonorrhea Mutates Into Treatment-Resistant Superbug

Attack of the Superbugs