The CDC estimates that at least 2 million people become infected by antibiotic-resistant bacteria each year, with at least 23,000 dying from these infections. “While much concern surrounds the inability to treat existing bacterial infections, clinicians must also keep in mind the ability of antibiotics to prevent infections after surgery or chemotherapy,” says Ramanan Laxminarayan, PhD, MPH. “As resistance rates rise, antibiotics become less effective, making surgery less safe and cancer treatment more difficult.”

Patients rely on antibiotics to be protect them from potentially deadly infections after undergoing many common medical procedures, including chemotherapy, pacemaker implantation, cesarean sections, and many others. The declining efficacy of existing antibiotics potentially jeopardizes outcomes in patients undergoing these procedures with regard to both morbidity and mortality.


Potential Consequences

For a study published in Lancet Infectious Diseases, Dr. Laxminarayan and colleagues reviewed clinical trials between 1968 and 2011 to investigate the potential consequences of greater antibiotic resistance on the 10 most common surgical procedures and immunosuppressing cancer chemotherapies that rely on antibiotic prophylaxis in the United States. The procedures included hip fracture surgery, pacemaker implantation, surgical abortion, spinal surgery, hip replacement, cesarean section delivery, prostate biopsy, appendectomy, hysterectomy, and colon surgery.

Using data from a computer model, the authors estimated the additional number of infections and infection-related deaths per year in the U.S. for various scenarios. They also estimated the percentage of pathogens causing infections after these procedures that are resistant to standard prophylactic antibiotics.

Results showed that between 39% and 51% of pathogens causing surgical site infections (SSIs) and 27% of pathogens causing infections after chemotherapy are resistant to standard prophylactic antibiotics. “If antibiotic resistance increases by 30% in the U.S., the resistant bacteria could cause 6,300 more deaths per year and 120,000 additional SSIs and infections after chemotherapy in patients undergoing these common surgical procedures,” Dr. Laxminarayan says. The study also showed that a 70% increase in resistance would lead to an additional 15,000 deaths and 280,000 infections annually.


Significant Ramifications

The study further illustrates the impact of the problem of antibiotic resistance, according to Dr. Laxminarayan. “Antibiotics are medications that just about every American will need at some point in their life,” he says. “Physicians and hospitals can help by limiting use of antibiotics to patients who truly need them and by putting tougher mandatory controls in place. The development of new antibiotics—while promising—will not help if effective antibiotic controls are not in place. It also may take many years before new antibiotics are introduced and established.”

The study notes that more data are needed to establish how antibiotic prophylaxis recommendations should be modified in the context of increasing rates of resistance. “Ultimately, efforts are needed to modify and adapt to antibiotic resistance in order to better serve patients in the future,” says Dr. Laxminarayan.