Becker's Clinical Quality & Infection Control

20 ANTIBIOTIC RESISTANCE & STEWARDSHIP Routinely Prescribed Antibiotic May Not Be Best Severe C. diff Treatment By Heather Punke S witching from using metronidazole to vancomycin as the initial treatment for severe Clostridium difficile infec- tions could have a significant effect on mor- tality rates, according to a study published in JAMA Internal Medicine. Current guidelines recommend using either metronidazole or vancomycin to treat C. diff infections. "For many years the two antibiotics were considered to be equivalent in their ability to cure C. diff and prevent recurrent disease," said Vanessa Stevens, PhD, the study's lead author. "Our work and several other studies show that this isn't always the case." For this study, researchers examined data from more than 10,000 patients treated for C. diff infections through the Department of Veterans Affairs healthcare system between 2005 and 2012. ey defined an infection as severe if the patient had an elevated white blood cell count or serum creatinine within four days of the diagnosis. About 35 percent of cases in this study were severe. ey found no differences in the risk of C. diff recurrence between patients treated with vancomycin and those treated with metronidazole. However, patients with se- vere C. diff who were treated with vancomy- cin were less likely to die than those treated with metronidazole. "e risk of 30-day mortality was signifi- cantly reduced among patients who re- ceived vancomycin," the study concludes. "Our findings may further justify the use of vancomycin as initial therapy for severe CDI [C. diff infection]." n Antibiotics Primary Driver for Rise in C. diff Infections, Study Finds By Brian Zimmerman R esearchers determined antibiotic misuse — not poorly cleaned hospitals — was the primary driver in surging rates of Clostridium difficile across the U.K.'s publicly funded healthcare system, according to a study published in January in The Lancet Infectious Diseases. High rates of C. diff across U.K. hospitals first came to public attention in 2006, spurring new deep cleaning protocols and a reduction in antibiotic use. The new protocols resulted in an 80 percent drop in C. diff rates, though the main driver of this reduction was unclear. To determine the primary cause of the spike in C. diff cas- es and identify the specific protocols that subsequently re- duced infection rates, researchers examined national data on the rates of C. diff from 2006 to 2014, antibiotic prescrib- ing data from the same time period and genome sequenc- es from 4,045 national and international C. diff isolates. The isolates were examined to determine the rate of C. diff infec- tions resistant to antibiotics. Analysis revealed limiting the number of prescriptions for antibiotics like fluoroquinolone was the primary cause of the significant drop in C. diff rates. "These findings are of international importance because other regions such as North America, where fluoroquino- lone prescribing remains unrestricted, still suffer from epidemic numbers of C. diff infections," said Dr. Derrick Crook, a study co-author and a microbiologist from Ox- ford University in the U.K. C. diff was linked to nearly 500,000 infections in the United States in 2011, according to the CDC. Approximately 29,000 of those infected died within 30 days of diagnosis. n When Travelers Use Antibiotics Abroad, Drug-Resistant Superbugs Can Hitchhike Home By Heather Punke T ravelers to areas like Latin America, Africa and South and Southeast Asia often carry antibiotics in case of infection, but treating diarrhea with those antibiotics can leave travelers at great risk of contracting extended spectrum beta-lactamases, or ESBL, bacteria. Such bacteria are resistant to penicillins and cephalo- sporins, so an infection is treated with antibiotics from other groups, like fluoroquinolones. Researchers recruited Finnish travelers for a study and col- lected stool samples before and after travel. Ninety of the travelers contracted an intestinal strain of ESBL bacteria on their trip and participated in a follow-up study. Among those who did not use an antibiotic, 37 percent had an ESBL strain resistant to fluoroquinolone. Nearly all (95 percent) of those who did use fluoroquinolone to treat their infection had a strain of ESBL bacteria resis- tant to that and other antibiotics. Usually, ESBL infections do not have symptoms. However, symptomless carriers can still spread the bacteria, which can cause life-threatening diseases in other people. "In practice this means that travelers pick up the most resistant strains of ESBL, and we are left with dwindling treatment options for ESBL infections," said Anu Kantele, MD, PhD, the study's lead author. "The spread of resistant strains of bacteria makes the sit- uation worse. Therefore, unnecessary use of antibiotics should be avoided also while traveling," Dr. Kantele said. n

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