WASHINGTON — The nation faces “potentially catastrophic consequences” if it doesn’t act quickly to combat the growing threat of antibiotic resistance, which kills an estimated 23,000 Americans each year, the Centers for Disease Control and Prevention (CDC) warned Monday.

In a 114-page report, the agency detailed for the first time nearly two dozen antibiotic-resistant bacteria that are causing the most harm to humans — ranking the threat of each as “urgent,” “serious” or “concerning.” Should the trend continue unabated, some infections could become essentially untreatable.

“If we’re not careful, the medicine chest will be empty when we go there to look for a life-saving antibiotic,” CDC Director Thomas Frieden told reporters Monday in a telephone news conference. “Without urgent action now, more patients will be thrust back to a time before we had effective drugs.”

One bacteria atop the agency’s “urgent” list of infections is carbapenem-resistant Enterobacteriaceae (CRE), which typically strike patients in medical facilities and has become resistant to nearly all existing antibiotics. Known as the “nightmare bacteria,” CRE causes life-threatening diarrhea. It has continued to proliferate and has been confirmed in medical facilities in nearly every state.

Likewise, Neisseria gonorrhoeae, which causes the sexually transmitted disease gonorrhea, has begun showing resistance to the antibiotics typically used to treat it, the CDC said. The condition, which can cause severe reproductive complications, shows up in an estimated 800,000 cases annually in the United States.

Clostridium difficile, or C. difficile, infections, which cause about 14,000 deaths per year, also made the agency’s urgent list Monday. While resistance to the antibiotics used to treat C. difficile infections hasn’t yet become a problem, the agency said the bacteria spreads rapidly because it is naturally resistant to many drugs that are used to treat other infections.

The CDC estimates that more than 2 million people in the United States are sickened each year by antibiotic-resistant infections, with 23,000 dying as a result. The agency said Monday that those numbers are conservative estimates and that the true figures likely are even greater.

The report said such infections also lengthen hospital stays and require more extensive treatment, adding “considerable and avoidable” costs to the nation’s already overburdened health-care system.

The overuse of antibiotics is the strongest factor contributing to antibiotic resistance around the globe. The more a particular germ is exposed to antibiotics, the more rapidly it can develop resistance.

The CDC said as much as half of all antibiotics that are prescribed are either unnecessary or used inappropriately. In addition, the vast majority of antibiotics used in the United States — 80 percent, by some estimates — are used in animal agriculture to promote growth and prevent and treat disease in livestock. Some consumer advocates have pushed Congress and the Food and Drug Administration to more tightly regulate the amount of antibiotics given to animals.

While Monday’s report detailed growing threats in the United States, the CDC reiterated that the problem is not defined by borders.

“New forms of antibiotic resistance can cross international boundaries and spread between continents with ease,” Monday’s report stated. “Many forms of resistance spread with remarkable speed.”

Steve Solomon, the CDC’s director of antimicrobial resistance, said in an interview that, while the agency is concerned about all 18 of the bacteria detailed in Monday’s report, the most troubling are those on the brink of resisting all current treatments.

“The ones at the edge of pan-resistance, we’re sounding an urgent alarm,” Solomon said. “We need to act now. We do not have antibiotics in the pipeline that are going to be available soon enough to address those problems.”

For those microbes and others that are increasingly resistent, the search for new antibiotics is essential, Solomon said.

“We need to invest in [finding] new antibiotics,” he said. “History has shown us the bacteria are always going to become resistant.”

If new drugs aren’t developed to replace the ones that have lost effectiveness, patients will face a dire predicament.

“We’re getting closer and closer to the cliff,” said Michael Bell, deputy director of the CDC’s division of health-care quality promotion. “When we no longer have that second-line drug to rely on, that’s when it’s a life or death matter.”

Beyond developing new treatments for antibiotic-resistant bacteria, the agency on Monday detailed an array of other actions that local communities, government officials and public-health professionals can take to minimize the sickness and deaths caused by the problem each year.

Those include more aggressive work to prevent infections, more closely monitoring resistant bacteria and taking steps to ensure that antibiotics are used more judiciously and wisely in humans and in animals.

“Only through concerted commitment and action,” the CDC wrote, “will the nation ever be able to succeed in reducing this threat.”


Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.