By Brenda L. Mooney
SALT LAKE CITY — Severe illness caused by the bacteria Clostridium difficile (C. diff) is now the most common hospital-acquired infection in the United States. A new VA-led study suggests, however, that it is not always being treated appropriately.
In a study published online by JAMA Internal Medicine, researchers from the Veterans’ Salt Lake City Health Care System and University of Utah reported that patients with the infection were less likely to die when treated with the antibiotic vancomycin compared to the standard treatment of metronidazole.1
One of the challenges in treating C. diff is the high mortality rate, as high as 26%. In 2011, almost a half-million Americans, mostly 65 or older, developed CDI, and 83,000 of them experienced recurrence of infection within 30 days of completing the standard course of antibiotics, according to the national Centers for Disease Control and Prevention (CDC).
“This is a very real problem that impacts the patients’ quality of life,” explained lead author Vanessa Stevens, PhD, a research assistant professor in the department of internal medicine and an investigator at the IDEAS 2.0 Center at the VA.
While the antibiotics metronidazole or vancomycin are recommended in practice guidelines to treat the condition, metronidazole has tended to be favored over the past few decades because of its lower cost and because of concerns about vancomycin resistance in other hospital-acquired infections.
“For many years, the two antibiotics were considered to be equivalent in their ability to cure C. diff and prevent recurrent disease,” noted Stevens, whose report pointed out that the study guidelines are based on small clinical trials from about three decades ago. “Our work and several other studies show that this isn’t always the case.”
For the current study, researchers sought to determine effectiveness of the two drugs by focusing on the risk of mortality after treatment.
Eligible patients included those with CDI as measured by the CDC laboratory—identified based on a laboratory test result that indicated the presence of C difficile toxin or toxin gene in a stool sample.
For purposes of the research, a severe case of Clostridium difficile infection (CDI) was defined as elevated white blood cell count or serum creatinine within four days of the CDI diagnosis, while a mild to moderate case of CDI was defined as normal white blood cell counts and creatinine levels.