The U.S. Centers for Disease Control and Prevention (CDC) this week released a report on antibiotic-resistant bacteria – and the news doesn’t look good. The CDC’s data shows that antibiotic resistance is on the rise in the U.S. The agency estimates that around two million Americans each year are infected with such germs, and that “at least” 23,000 of them die from the infections.

“Antibiotic resistance is rising for many different pathogens that are threats to health,” said Dr. Tom Frieden, director of the CDC. “If we don’t act now, our medicine cabinet will be empty and we won’t have the antibiotics we need to save lives.”

Antibiotic-resistant bacteria are infections that don’t respond to normal antibiotics. Bacteria can become resistant to antibiotics simply by being exposed to them. The frequency with which bacteria are exposed to antibiotics can affect how quickly they are able to evolve a resistance.

The CDC is warning that up to 50% of all antibiotic use in unneeded or “not prescribed appropriately.” In addition, the overuse of antibiotics on livestock is a concern for the agency. According to the CDC, improving antibiotic use (by using them only when medically necessary) is the most important factor for slowing the spread of antibiotic-resistant strains of bacteria.

“Every time antibiotics are used in any setting, bacteria evolve by developing resistance,” said Dr. Steve Solomon, M.D., director of CDC’s Office of Antimicrobial Resistance. “This process can happen with alarming speed. These drugs are a precious, limited resource – the more we use antibiotics today, the less likely we are to have effective antibiotics tomorrow.”

In addition to the yearly deaths antibiotic-resistant bacteria causes in the U.S., the CDC has also compiled statistics on the monetary costs. The agency estimates that $20 billion in health care costs can be attributed to antibiotic resistance and that as much as $35 billion in lost productivity can be connected to such infections.