The Mounting Crisis of a Silent Pandemic: Antimicrobial Resistance

“If left unchecked, Antimicrobial Resistance could cost losses of between $1 trillion and $3.4 trillion in global Gross Domestic Product by 2030.”

World Bank, September, 2025

“Infections of Drug-Resistant ‘Nightmare Bacteria’ Are Surging in Hospitals.”

Lauren J. Young, Scientific American, September 24, 2025

Antimicrobial resistance (AMR) is the ability of pathogens to evade the treatment effects of antimicrobial drugs. In the U.S. more than 2.8 million AMR infections occur every year, resulting in over 35,000 deaths. Globally, the situation is even worse; in 2022, more than 3 million deaths of children worldwide were linked to AMR.

AMR is a “silent pandemic,” a slow moving crisis that while often overlooked is nonetheless escalating. On September 23, 2025, scientists at the Centers for Disease Control and Prevention reported that between 2019 and 2023, a 461% increase occurred in the infection rate of bacteria in the Enterobacterales group of bacteria that are resistant to all antibiotics. In this week’s post, I provide an update on this crisis—a crisis that many Public Health experts consider the biggest worldwide infectious disease threat of all. (See, “Battling Antimicrobial Resistance: WHO’s on Board. Who Else?”, Germ Gems, May 22, 2024).

What is AMR? AMR is when bacteria, viruses, fungi, or parasites change over time and no longer respond to antimicrobial medicines. Several groups of bacteria—both gram-positive, like methicillin-resistant Staphylococcus aureusand Streptococcus pneumoniae, and gram-negative, such as carbapenem-resistant Enterobacterales (CRE)—garner the most AMR attention. But AMR is also a huge problem not only in other bacteria, e.g., Mycobacterium tuberculosis, the cause of tuberculosis, but also in viruses, such as HIV, the cause of AIDS, fungi, like Candida auris, and parasites, including Plasmodium, the cause of malaria.

Why does AMR develop? The emergence of AMR is largely a natural phenomenon. Microbes of all sorts have the capacity to evolve, that is, develop mechanism that promote their survival in the face of pressures from the environment, such as the presence of antimicrobial agents. The presence of these gene-based resistance mechanisms can even be found in microbes living in environments where antibiotics have never been used. Even though the emergence of AMR can be considered a natural phenomenon, humans, namely physicians and farmers, are guilty of aiding and abetting this “crime.”

In the case of physicians, the most common offense is the misuse of antibiotics. Antibiotics are only of value in treating bacterial infections and the misuse of antibiotics can foster the emergence of AMR. This is a major issue in primary care settings. Researchers at Huazhong University of Science and Technology, Wuhan, China, found that antibiotics accounted for 42 out of 100 primary care prescriptions worldwide, yet more than half of these were prescribed inappropriately. (Song, Q., et al., “Worldwide antibiotic prescription practices in primary care and associated factors: A systemic review and meta-analysis,” American Journal of Infection Control, September 2, 2025).

Many physicians prescribe antibiotics for the treatment of non-bacterial infections, most commonly viral infections. This misuse of antibiotics occurred in spades during the COVID-19 pandemic, a pandemic caused by the virus SARS-CoV-2.  According to a study conducted by researchers at the University of Wisconsin, 45% of patients with COVID-19 received a potentially unnecessary antibiotic during hospitalization. (Pulia, M.S., et al., “National Trends in Antibiotic Prescribing for Adults Hospitalized with Coronavirus Disease 2019 and Other Viral Respiratory Infections,” Open Forum Infectious Diseases, February 19, 2025).

And, it appears that it is not only the misuse or overuse of antibiotics that can foster the emergence of AMR.  Researchers at the University of South Australia recently found that ibuprofen and acetaminophen appear to enhance mutations in E. coli, making the common bacteria more resistant to the broad-spectrum antibiotic ciprofloxacin. (Chen, H., et al., “The effect of commonly used non-antibiotic medications on antimicrobial resistance development in Escherichia coli,” Antimicrobials and Resistance, August 25, 2025). They also found that when used together, the two drugs amplify this effect. As the lead researcher stated in a press release, “Antibiotic resistance isn’t just about antibiotics anymore.”

In the case of farmers, and others involved in the livestock industry, their unintended contribution to the emergence of AMR occurs by adding antibiotics to animal feed as a means of fattening up poultry, swine, cattle, chickens, and sheep. This creates a dynamic where resistance in one area can emerge and spread to others, for example when resistant bacteria from farm animals contaminate food or water. Retail meat is a prime example of this happening in the food supply chain.

According to analysis of data from the Food and Drug Administration, “[o]ver one-third of U.S. retail meat samples tested positive for at least one type of potentially harmful bacteria, and nearly 1 in 4 bacterial isolated collected were multidrug-resistant.” (Dall, C., “Analysis highlights bacterial contamination, multi-drug resistance, in retail meat samples,” CIDRAP News Brief, June 18, 2025; see also, Dall, C., “Multidrug-resistant Salmonella strains are spreading in poultry, study suggests,” CIDRAP News Brief, July 22, 2025).

Finally, there are several human-related behaviors that have been linked to emergence of AMR. These include human involvement in climate change (Dall, C., “Climate change could increase global levels of antimicrobial resistance, study finds,” CIDRAP News, April 28, 2025) as well as human conflict ( Stone, R., “War-torn Ukraine is breeding drug-resistant bacterial strains,” AMR Insights, November 29, 2024; Ebied, M., “How Human Conflict Accelerates Antimicrobial Resistance,” American Society for Microbiology, September 2, 2025). As Scott Pallett of the Royal Centre for Defence Medicine said, “The level of drug resistance we are seeing in Ukraine heralds the peril of a postantibiotic era.”

Potential solutions. There is increasing evidence that “Antibiotic Stewardship Programs,” usually staffed by expert physician and pharmacist teams, make a difference in improving antibiotic prescribing.  (Kahn, K., “In-Hospital Infections, Antimicrobial Resistance Declined Over 13 Years,” MedPage Today, August 15, 2024; Dall, C., “CDC study shows drop in antibiotic prescribing at US nursing homes,” CIDRAP News, November 21, 2024). But this is not enough.  Other innovative approaches to solving AMR need to be used.

In the past several years, re-thinking of the duration of antimicrobial use for a number of infectious diseases has become a proved strategy to reduce the burden of antimicrobial agents in the environment. This concept –“shorter is better”—is backed by a number of experts in the field of infectious diseases and by studies that have shown benefits without loss of safety. (See, e.g, Lowey,  Matias A., “More Days, More Resistance: Time to Rethink Antibiotics,” Medscape Medical News, June 20, 2025;  Daneman, N., et al., “Antibiotic Treatment for 7 versus 14 Days in Patients with Bloodstream Infections,” New England Journal of Medicine, March 13, 2025; Langford, B., et al., “Evaluating Harms Associated with Prolonged Antibiotic Duration of Therapy in Community-Dwelling Older Adults: A Cohort Study Using Instrumental Variable Analysis,” Clinical Infectious Diseases, December 30, 2024).

Two other approaches that address the escalating threat of AMR stand out in my mind. One is the use of bacteriophages, that is, “viruses that eat bacteria.”  (See, e.g., Cornman, E., “Antibiotic Resistance: Fighting With ‘Phage-hunting’ and More,” Yale School of Medicine News, October 31, 2024; Asanga, P. ,“A Fix for Antimicrobial Resistance Could Be Hiding in the Past,” Healthcare Security, September 15, 2024). The second is to step up the pace of a tried and proved method for discovery of antimicrobial agents, that is “digging in the dirt.” Historically, the so-called “antibiotic pipeline” has been filled in no small part by scientists exploring all kinds of nooks and crannies for microbes that produce antimicrobial agents. ( See, e.g., Mallapaty, S., “New antibiotic that kills drug-resistant bacteria discovered in technician’s garden,” Nature, March 28, 2025).

Crucial Role of Collaboration.  Collaboration is our strongest weapon against antimicrobial  resistance, and the “One Health” movement could have a huge impact. (Singh, Reema, “Fighting the silent pandemic: Collaboration is our strongest weapon against antimicrobial resistance,” Science Speaks blog, August 13, 2025.) The engineering community, among others, stands to serve as a critical One Heath collaborator. (Schweitzer, K.,  “Five Engineering Advancements That May Help Solve the Growing Threat of Antimicrobial Resistance,” Journal American Medical Association, February 28, 2025).

The “One Health” approach has its roots in the 19^th and 20^th centuries. A modern (2023-present) definition of “One Health” is an integrated, unifying approach that aims to sustainably balance  and optimize the health of people, animals, and ecosystems.  This approach is “essential for tackling AMR precisely because it recognizes that human, animal and environmental health are deeply connected.”  Resistance cannot be addressed by focusing on just one part of this delicate system. Instead we need diverse shareholders presenting a united front: a shared goal against AMR. (Note: The Infectious Diseases Society of America plays an instrumental role in fostering this essential collaboration.)

In the fall of 2024, those leading the effort to decrease AMR convened and called for a “One Heath approach that encourages disciplines beyond human health care—such as agriculture, animal health biopharmaceuticals, and wastewater and the environment—to join forces to improve practices and innovate solutions.”  On September 24, 2025 the European Union announced the “EU One Health Plan Against AMR.” As of this writing, the U.S. is a close collaborator and partner with this EU initiative.  Given the enormity of the AMR problem, all countries need to be on board this partnership.