By Marie Rosenthal, MS

In a new report released today, the CDC said antibiotic-resistant bacteria and fungi cause more than 2.8 million infections in the United States, and 35,000 of them end in death.

That means on average, “a death from antibiotic-resistant infection occurs about every 15 minutes, and a resistant infection occurs ever 11 seconds,” CDC Director Robert R. Redfield, MD, said in a telebriefing.

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Using data sources not previously available, the updated “Antibiotic Resistance Threats in the United States, 2019” (2019 AR Threats Report) categorizes the 18 top antibiotic-resistant threats based on level of concern to human health: urgent, serious or concerning. The CDC added two new organisms—drug-resistant Candida auris and carbapenem-resistant Acinetobacter—to the list of urgent threats, bringing the most serious organism list to five: these plus carbapenem-resistant Enterobacteriaceae (CRE), Neisseria gonorrhoeae and Clostridioides difficile, added in 2013.

“One in three patients infected by invasive C. auris dies,” Dr. Redfield said, “and some samples of resistant and rare fungus had been shown to be resistant to all three classes of antifungal drugs.” 

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Since being identified in Asia in 2009, C. auris has become a cause of severe infections around the world. It spread to the United States in 2015, with reported cases increasing 318% in 2018, according to the report.

Carbapenem-resistant Acinetobacter, which causes pneumonia and wound, bloodstream and urinary tract infections, often affects people in ICUs. Unfortunately, resistant Acinetobacter can carry genetic elements that are easily shared among bacteria, rapidly spreading its resistance. In addition, the bacteria can survive a long time on surfaces, according to the report. 

Luckily, resistance among CRE infections has remained stable. Patients who require devices, such as catheters, and who take antibiotics for long periods are most at risk for CRE infections. They also carry genetic resistance that can be shared with other bacteria. Some CRE are resistant to nearly all antibiotics, leaving treatment options that are not only less effective but also more toxic.

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Drug-resistant N. gonorrhoeae is a growing concern. More than half a million resistant gonorrhea infections occur each year: twice as many as reported in 2013. N. gonorrhoeae has developed resistance to all but one class of antibiotics, and half of all infections are resistant to at least one antibiotic. 

Although C. difficile is not typically resistant, its association with antibiotic use makes it a growing threat, according to the CDC. If added to the tolls above, the threats listed in the report exceed 3 million infections and 48,000 deaths: more than twice as many deaths than in the original 2013 report.

The report also identifies three additional organisms—azole-resistant Aspergillus fumigatus, drug-resistant Mycoplasma genitalium and drug-resistant Bordetella pertussis—that have yet to spread resistance widely or are not well understood in the United States, but that the CDC and other public health experts are monitoring closely.

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For this new report, which used electronic health record data from hospitals for the first time, the CDC studied how estimates of antibiotic-resistant infections and deaths have changed over time, and the result is a mixed bag. Although resistant infections and deaths from organisms often associated with hospitals are steadily declining—deaths from antibiotic-resistant infections in hospitals went down 28% from 2012 to 2017—resistance to essential antibiotics is increasing in seven of the 18 organisms on the list, and the concern is moving into the community, according to Michael Craig, MPP, of the CDC’s Antibiotic Resistance Coordination and Strategy Unit.

“The CDC is concerned about other rising resistant infections in our communities,” he said. “These infections are putting people at risk and undermining gains made in health care. Infections in the community can happen to healthy people, making spread more difficult to identify and contain the urgent threat.”
For instance, extended-spectrum beta-lactamase–producing Enterobacteriaceae are one of the leading causes of death from resistant organisms, making urinary tract infections harder to treat, especially in women, and invasive infections from erythromycin-resistant group A Streptococcus have quadrupled since the 2013 report.

The CDC experts analyzed data from various CDC data systems to create the 2019 AR Threats Report. These data and new methodologies provide more precise, although still conservative, estimates of the human costs of antibiotic resistance.

For the first time, the CDC used electronic health data from U.S. hospitals to measure the burden of antibiotic-resistant infections, including attributable mortality, for seven of the 18 germs listed. 

The CDC researchers assessed all 18 threats according to seven factors associated with resistant infections: health impact, economic impact, how common the infection is, a 10-year projection of how common it could become, how easily it spreads, availability of effective antibiotics, and barriers to prevention. Because new methods have been used, the burden of some organisms can be compared with the 2013 estimates while others cannot.

“We used several data sources to generate these national estimates,” Mr. Craig explained. “We also did a look back at our 2013 report data. The CDC used the best data available at the time, but we knew and said then that our estimate was conservative and likely underestimated the true burden of antibiotic resistance.

“And we were right [based on] the new data available,” Mr. Craig said.

Although the numbers and some of the threats have changed, the response has not, according to Dr. Redfield:

“The global community needs more innovation, new treatment options, reliable diagnostics and better data that will help protect people,” Dr. Redfield said.

“Despite significant progress, this threat remains our enemy,” he said. “Join us in this important mission to effectively communicate the risk posed by antibiotic resistance and the important role that each of us has in combating this threat.”