HOSPITAL PRACTICE

Where hospitals are stanching antibiotic resistance

Controlling the spread of antibiotic-resistant bacteria, an endeavor frequently criticized as long on talk and short on action, is having a few, small successes, with a funding victory in Congress and reports of hospitals rolling back the incidence of antibiotic-resistant infections.

Speaking at the 2002 Conference on Antimicrobial Resistance, sponsored by the National Foundation for Infectious Diseases, Rep. Sherrod Brown (D, Ohio) announced that the recently passed bioterrorism bill authorizes an annual $25 million grant program to help hospitals monitor antibiotic resistance. No two hospitals have identical patterns of antibiotic resistance, and tracking the incidence of resistance is an essential first step in reducing incidence.

According to the Centers for Disease Control & Prevention, more than two million Americans each year get infections in hospitals, and more than 70% of the bacterial strains involved resist at least one antibiotic. Extended hospital stays and more expensive alternate antibiotics to treat these infections cost an estimated $4.5 billion annually.

Antibiotics are a unique drug class in that misuse with some patients can prevent others from using them at all, said Stuart B. Levy, president of the Alliance for Prudent Use of Antibiotics. In this sense, antibiotics are societal drugs, and overuse, particularly of broad-spectrum antibiotics, places society at risk by hastening the emergence of antibiotic resistance. For two reasons, this problem grows more urgent, he said. One is the spread in hospitals of untreatable strains resistant to multiple drugs, including vancomycin, the antibiotic of last resort. Vancomycin-resistant enterococci (VREs) and staphylococci are particularly worrisome.

The other reason is the spread of antibiotic resistance outside of hospitals. "Many of us have witnessed the movement of multiple-drug-resistant infections from hospital origins to the community following increased use of antibiotics in a community," he said, citing the case of an 11-month-old child with refractory otitis media who had to be hospitalized. "Her organism was resistant not just to penicillin, but also to clindamycin, erythromycin, trimethoprim-sulfone combinations, and tetracycline." Other children attending the day care center in the child's small Georgia community turned out to be colonized with the same organism.

A few hospitals are showing that the incidence of antibiotic resistance can be reduced. An example is Highland General Hospital in Oakland, Calif., where, in 1999, more than 90% of enterococci isolates were vancomycin-resistant, and 45%-50% of gram-negative rod pathogens resisted both penicillin-class drugs and cephalosporins. Gram-negative resistance was caused by widespread use of third-generation cephalosporins. Indirectly, cephalosporins also boosted the VRE rate, because reducing gram-negative bacteria in patients' bowels provided small populations of VREs more room to grow. Fecal contamination then helped VREs to spread within the hospital.

A solution was found by giving physicians pocket-sized guides recommending equally efficacious alternatives to third-generation cephalosporins for each type of infection and for patients with special conditions, such as penicillin allergy and renal insufficiency. Within two years, said Larry B. Lambert, clinical microbiologist at the hospital, the VRE rate was reduced to 20%, while resistant gram- negatives fell to less than 20%.

Another cause of antibiotic resistance is the administration of antibiotics to healthy farm animals, usually to promote growth and prevent infections. Research indicates that antibiotic-resistant strains developed on farms spread through animal feces into the water supply and from there to humans. To end nontherapeutic use of antibiotics on farms, Brown has introduced H.R. 3804, the Preservation of Antibiotics for Human Treatment Act of 2002. The bill, with bipartisan support and endorsed by the American Medical Association, phases out the feeding of eight classes of antibiotics to healthy farm animals. The drugs can still be used for veterinary care.

Thomas Hollon, Ph.D.

The author is a writer in the Washington, D.C., area.

For more information

Here are two Web sites that provide more information on antibiotic resistance:

Alliance for Prudent Use of Antibiotics—
www.apua.org

Centers for Disease Control & Prevention campaign to prevent antimicrobial resistance in healthcare settings—
www.cdc.gov/drugresistance/healthcare/

 

Tom Hollon. Where hospitals are stanching antibiotic resistance. Drug Topics 2002;15:55.