On October 27 the U.S. Centers for Disease Control and Prevention (CDC) released a report identifying the 19 most dangerous pathogens—such as bacteria and fungi—that are developing “the ability to defeat the drugs designed to kill them.” Each year in the United States alone, these “superbugs” are responsible for 50,800 deaths and 9.7 million infections. The hospital-associated infections among them cause more than 42,000 deaths and over $12 billion in added health care costs.

The most “urgent” threat comes from four drug-resistant organisms that include the carbapenem-resistant strains of the Acinetobacter group of bacteria that cause pneumonia, wound, bloodstream, and urinary tract infections. Carbapenem is the group of antibiotics, considered by many to be the strongest in the world, and used when all other drugs fail. Also on the CDC’s “urgent” list are the carbapenem-resistant strains of the Enterobacterales bacteria that are known for infecting patients who use medical devices such as ventilators and catheters. The list also includes the drug-resistant fungus Candida auris, which can quickly spread through entire hospitals and nursing homes. There is a tenfold increase in Candida auris infections compared to 2019, when the CDC issued its last such report. Another top concern is the bacteria that cause gonorrhea, which has become resistant to nearly every class of antibiotic used against it.

One potentially fatal group of bacteria, Clostridioides difficile (often abbreviated as C. diff), was downgraded from the CDC’s “urgent” list to “serious” because of greatly improved prevention and antibiotic management in hospitals. It still kills some 10,000 people annually.