Nov 13, 2019 - Health

More Americans die from superbugs than previously estimated, CDC says

Antibiotic-resistant (AR) bacteria and fungi cause more than 2.8 million infections and 35,000 deaths annually in the U.S., according to new estimates posted by the Centers for Disease Control and Prevention in a long-awaited report. But, while the overall numbers are "higher than previously estimated," the number of people dying from AR infections appears to be dropping.

The five most urgent out of 18 threats of antibiotic-resistant bacteria and fungi pointed out in the CDC's report. Data: 2019 AR Threats Report; Images: CDC; Table: Andrew Witherspoon/Axios
The five most urgent out of 18 threats of antibiotic-resistant bacteria and fungi pointed out in the CDC's report. Data: 2019 AR Threats Report; Images: CDC; Table: Andrew Witherspoon/Axios
"A death from antibiotic resistant infections occurs every 15 minutes and new infections happen every 11 seconds. ... Antibiotic resistance remains a persistent enemy ... we must remain vigilant."
— Robert Redfield, CDC director, at a press briefing

Background: The "Antibiotic Resistance Threats in the United States" report is the CDC's first major update since 2013. At that time, the three most "urgent" threats were Clostridioides difficile, Carbapenem-resistant Enterobacteriaceae (CRE) and Drug-resistant Neisseria gonorrhoeae. There were another 12 "serious" threats and three "concerning" threats.

  • The 2013 report estimated that 2 million Americans were infected with antibiotic resistant germs annually, leading to at least 23,000 deaths.
  • But, for the 2019 report, the CDC used electronic health records from more than 700 geographically diverse, acute-care hospitals.
  • Using those new data sources, CDC "looked back" at 2013's original "conservative" data and revised estimates to 2.6 million infections and 44,000 deaths.
  • Of note: Neither report contains viruses or parasites.

What's new: Overall, 2019's results are mixed. There's a growing number of AR bacteria and fungi that the CDC calls greatly concerning; but there's also a lower number of deaths from these infections.

  • There are now five "urgent" threats — the three listed in 2013, plus two new ones: Carbapenem-resistant Acinetobacter and Candida auris.
  • The CDC also lists 11 "serious" threats, two "concerning" threats, and three on its watch list.

By the numbers, per CDC: AR bacteria and fungi currently cause more than 2.8 million infections and 35,000 deaths in the U.S. each year.

  • Since 2013, CDC says prevention efforts have reduced deaths from AR infections by 18% overall, and nearly 30% in hospitals.
  • But, when adding in Clostridioides difficile, a bacteria not typically considered AR but associated with antibiotic use, the current total reaches more than 3 million infections and 48,000 deaths per year.
  • Resistance to essential antibiotics is increasing in seven of the 18 germs.
  • Some good news: Infections from CRE, dubbed the "nightmare bacteria" — as it kills almost half of patients with bloodstream infections — remained stable despite the speed with which the deadly germ can spread. This showcases that improvements have made, partly from CDC's containment strategy, Arjun Srinivasan, associate director of CDC's HAI prevention programs, tells Axios.

What we're watching: There are some new threats CDC flagged.

1. Emerging threats: Bacteria and fungus evolve quickly, presenting new challenges. One is antibiotic resistant C. auris, a fungus that popped up as a problem a couple years ago in several countries simultaneously — an "unusual occurrence," Redfield says.

  • Scientists continue their efforts to determine how and why this form of C. auris emerged, as well as its root cause, Michael Craig, of the CDC's antibiotic resistance coordination and strategy unit, told the press in a briefing.
"Candida auris is a great contemporary example of the challenges from antibiotic resistant infections [that are] emerging. ... We didn't even know about it when we put out our report in 2013."
— Michael Craig

2. Community infections: The CDC is also concerned about the rising number of infections seen in outpatient care and within communities, Srinivasan says, like those associated with drug-resistant gonorrhea and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae.

  • One of the problems is that Enterobacteriaceae can transfer resistance to other members of its "family," including common infections like yeast infections and urinary tract infections.

The big picture: While improvements have been made, particularly in some hospital settings, overall antibiotic resistance and infections are spreading rapidly with new threats emerging. The CDC is calling for more vigilance and appropriate antibiotic use.

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