Drug-resistant infections are one of the most under-appreciated public health threats facing America today, and California is taking action before a scraped knee becomes life-threatening. In 2019, the CDC estimated that drug-resistant infections caused nearly 3 million illnesses and 35,000 deaths in the United States, with more than $20 billion in direct healthcare costs. Yet unlike flashy disease outbreaks, antimicrobial resistance rarely makes headlines, even as the bacteria and fungi that cause it grow stronger each year.

What Happens When Antibiotics Stop Working?

Dr. Christina Lin, an infectious diseases physician at Stanford University, sees the consequences of antibiotic resistance every day in her patients. She explained a pattern that's becoming increasingly common: "A relatively healthy person catches a routine respiratory virus like flu, which damages their lungs, allowing bacteria to take hold. One common culprit is Staphylococcus aureus, or staph, a bacteria many of us carry on our skin. But in a vulnerable lung, it can cause life-threatening pneumonia". When staph becomes resistant to standard penicillin-based antibiotics, it's called methicillin-resistant Staphylococcus aureus, or MRSA. At that point, doctors must reach for more intense, intravenous antibiotics, hoping they work.

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"As an infectious diseases doctor at Stanford, I care for patients with life-threatening infections that, year after year, are becoming harder to treat, because the drugs that once cured these infections are no longer effective," stated Dr. Christina Lin.

Dr. Christina Lin, Infectious Diseases Physician at Stanford University

The problem is fundamental to how antibiotics work. When we use these drugs, any microbe carrying the right genetic mutation survives. When those survivors reproduce, the next generation all carry the defense against that drug. At massive scale, in hospitals, veterinary clinics, and agriculture, this process accelerates, creating "superbugs" that can defeat multiple drugs at once.

Which Drug-Resistant Infections Should Californians Know About?

California is tracking four particularly concerning drug-resistant pathogens that are either spreading rapidly or becoming harder to treat:

• MRSA (Methicillin-Resistant Staphylococcus Aureus): Staph is a natural survivor that sticks to heart valves, bones, and implanted medical devices. Once it invades, it's hard to kill even with the most effective antibiotics. From 2017 to 2023, MRSA bloodstream infections in California acute care hospitals have been steady or decreasing, but the bacteria remains a serious threat when it takes hold.
• Candida Auris (C. Auris): This fungus spreads rapidly among vulnerable patients in hospitals and long-term care facilities. Some strains resist all three major classes of antifungal drugs, making them essentially untreatable. Outbreak mortality rates can reach 30 to 60 percent. Since a 2019 outbreak in Orange County, California cases have climbed every year.
• Carbapenemase-Producing Organisms (CPOs): These bacteria carry an enzyme that breaks down carbapenems, a critical class of antibiotics that doctors reach for when pathogens are still being identified or when bacteria resist other drugs. CPOs cause over 10,000 deaths annually in the United States, and reported cases in California have increased since 2019.
• Drug-Resistant Gonorrhea: This sexually transmitted infection has steadily developed resistance to every antibiotic deployed against it, including penicillins, tetracyclines, and fluoroquinolones. The worst complications, including pelvic inflammatory disease and infertility, fall disproportionately on communities with less access to timely treatment. In 2025, two new antibiotics received FDA approval for treating uncomplicated gonorrhea.

The rise of C. auris is particularly alarming. California detected its first outbreak in Orange County in 2019, and cases have climbed every year since then. Unlike MRSA, which can spread in the community, C. auris risk is highest in healthcare settings where vulnerable patients are concentrated.

How to Combat Antibiotic Resistance in Your Community

Stopping the spread of drug-resistant infections requires action at multiple levels, from individual behavior to healthcare policy. Here's what experts say needs to happen:

• Surveillance Systems: Early detection of resistant pathogens allows public health officials to contain spread before it becomes widespread. The California Department of Public Health maintains dashboards tracking C. auris and CPOs across healthcare facilities, feeding into outbreak investigations at the county and local levels. This infrastructure gives officials insight into when resistant strains emerge and when protective measures should be undertaken.
• Reducing Overuse in Agriculture and Healthcare: California has one of the most protective laws in the country requiring a veterinarian's prescription before antimicrobials can be used in livestock. In hospitals and clinics, antimicrobial stewardship programs help clinicians choose the right drug at the right dose for the right duration. The CDC estimates that about 30 percent of antibiotics prescribed in doctor's offices and emergency departments are not needed.
• Preventing Spread in Healthcare Settings: Infection prevention programs in hospitals are critical for containing drug-resistant pathogens. Dedicated teams track hospital-associated infections and enforce strict measures, including hand hygiene, wearing personal protective equipment, disinfecting rooms and medical equipment, and monitoring high-risk patients for resistant infections like C. auris.
• Personal Prevention Habits: Practicing healthy habits such as washing hands, preparing food safely, and using condoms can prevent infections before they happen. Chronic conditions such as diabetes increase vulnerability to serious infections, making disease management especially important.

Dr. Lin emphasized that everyone has a role to play. "The burden of AMR doesn't make headlines the way outbreaks do, but it's something we can't ignore, and each of us has a part to play in finding solutions," she noted. Taking care of yourself through basic hygiene and preventive care is the first line of defense against needing antibiotics in the first place.

Dr. Lin

The stakes are high. Without action, we risk returning to a pre-antibiotic era where routine infections become life-threatening. California's focus on surveillance, stewardship, and prevention offers a roadmap for how other states can tackle this growing threat before drug-resistant infections become the norm rather than the exception.