Drug-resistant bacteria and fungi cause an estimated 9.7 million infections and 50,800 deaths in the United States each year, according to a new report from the Centers for Disease Control and Prevention (CDC), which warns that antimicrobial resistance remains a growing threat to public health.

The report identifies 19 drug-resistant germs that pose varying levels of danger, including four classified as urgent threats, the CDC’s highest risk category. The agency’s updated estimates exceed those in its 2019 report, although officials said changes in measurement methods account for part of the increase.

Healthcare-associated infections account for more than 42,000 deaths annually and add nearly $12 billion to healthcare costs, underscoring the burden resistant germs place on hospitals, nursing homes and patients.

“Antimicrobial resistance threatens modern medicine and puts millions of Americans at risk every year,” CDC Director Dr. Erica Schwartz said in a statement.

Among the most concerning pathogens is Candida auris, a drug-resistant fungus that can spread in hospitals and nursing homes and is resistant to many antifungal medications. Reported U.S. cases climbed from 48 in 2016 to 6,304 in 2024, highlighting the rapid expansion of a pathogen that can be particularly dangerous for medically vulnerable patients.

The CDC also designated carbapenem-resistant Acinetobacter and carbapenem-resistant Enterobacterales, known as CRE, as urgent threats. These bacteria can cause pneumonia, bloodstream infections, wound infections, and urinary tract infections. They are especially concerning in intensive care settings, where patients may already have weakened immune systems or require invasive medical procedures. CRE bacteria can also transfer resistance mechanisms to other germs, complicating efforts to control their spread.

The fourth urgent threat is drug-resistant Neisseria gonorrhoeae, the bacterium responsible for gonorrhea. Its growing resistance to antibiotics threatens to make an already common sexually transmitted infection increasingly difficult to treat.

Carbapenems are powerful antibiotics often reserved for serious infections when other medications are ineffective. Resistance to these drugs leaves doctors with fewer treatment options for some of the most vulnerable patients.

The CDC classified another 13 germs as serious threats and two as concerning, while placing six additional pathogens on a watch list.

Dr. Helen Chu, an infectious disease physician at the University of Washington in Seattle, told The Washington Post that she has seen more severe infections among hospitalized patients, including drug-resistant gonorrhea and necrotizing fasciitis, a potentially life-threatening infection that destroys soft tissue.

“We saw an uptick of these cases in the last few years, the ‘flesh-eating bacteria’ that we worry about,” Chu said.

The report also identified progress in combating certain infections. Clostridioides difficile, commonly known as C. diff, was classified as an urgent threat in 2019 but has since been downgraded to serious. The CDC attributed the improvement to better diagnostic practices and more effective infection-prevention measures in hospitals and other healthcare facilities.

Despite that progress, medical experts warn that antimicrobial resistance could undermine routine treatments and complex procedures. Chemotherapy, organ transplants, and joint replacements frequently depend on antibiotics to prevent or treat infections, making resistant germs a threat to the safety of modern medical care.

Antimicrobial resistance develops when bacteria and fungi evolve mechanisms that allow them to survive medications intended to eliminate them. The use and misuse of antimicrobial drugs can accelerate that process by giving resistant organisms opportunities to survive and spread.

The CDC advises patients to use antibiotics only when medically necessary and to follow their healthcare provider’s instructions. Antibiotics do not treat viral illnesses such as colds and influenza, and taking them unnecessarily provides no benefit against those infections while contributing to resistance.

The agency also advises patients not to pressure doctors into prescribing antibiotics or save leftover medication for future illnesses. Using the wrong drug, dosage, or treatment duration can contribute to resistance and make future infections harder to control.

The CDC’s findings highlight the need for stronger infection prevention, appropriate antibiotic use, and continued surveillance as hospitals and healthcare providers confront germs that increasingly evade available treatments.