Reducing Antibiotics Cuts C. difficile rates

Hospitals around the world have taken a number of steps to limit the number of dangerous Clostridium difficile infections affecting patients each year. Now, a new study may have found the key to reducing C. difficile rates: reducing antibiotics.

C. difficile bacteria cause a potentially deadly form of diarrhea, with the Centers for Disease Control and Prevention (CDC) reporting that nearly half a million such infections occurred in the United States in a single year. Of those infected, about 15,000 die each year directly due to the superbug, with more than 80% of those deaths occurring in individuals who are 65 years of age and older. These bacteria spread through spores, which can persist on contaminated surfaces, on hands, and in people who carry the spores. Even more troubling is that these bacteria can be highly resistant to disinfectants. Use of antibacterial copper surfaces and spore-killing ultraviolet light are some of the novel manneres by which hospitals are attempting to eliminate C. difficile contamination, but a recent study found that the spores are able to spread outside of hospitals through used patient linens at laundry facilities.

In a recent study published in The Lancet Infectious Diseases journal, though, a team of researchers found that limiting antibiotic overuse effectively reduces the number of cases of hospital-acquired C. difficile. The study team, including researchers from the University of Oxford, University of Leeds, and Public Health England, investigated 4,885 cases of hospital-onset C. difficile occurring from January 1, 1997 to December 31, 2012 in Scotland, and found prevalence of these infections to be associated with the use of the antibiotics fluoroquinolone, third-generation cephalosporin, macrolides, and carbapenem. On May 1, 2009, healthcare providers began an antibiotic stewardship and infection reduction initiative, which included a 50% decrease in antibiotic use in the hospitals included in the study, along with interventions such as the introduction of alcohol-based hand sanitizer, a national hand hygiene campaign, national auditing, and inspections of hospital environment cleanliness; they also included reminders to reduce inappropriate use of proton-pump inhibitors.

The researchers found that it was only with the restriction of fluoroquinolones, and with more targeted use of the antibiotics, that the number of antibiotic-resistant C. difficile infections declined. "Emergency measures such as 'deep cleaning' and careful antibiotic prescribing were introduced and numbers of C. difficile infections gradually fell by 80% but no one was sure precisely why,” explained study author Derrick Crook, FRCP, in a recent press release. "Our study shows that the C. difficile epidemic was an unintended consequence of intensive use of an antibiotic class, fluoroquinolones, and control was achieved by specifically reducing use of this antibiotic class, because only the C. difficile bugs that were resistant to fluoroquinolones went away. Reducing the type of antibiotics like ciprofloxacin was, therefore, the best way of stopping this national epidemic of C. difficile and routine, expensive deep cleaning was unnecessary. However, it is important that good hand hygiene continues to be practiced to control the spread of other infections.”

The researchers noted another interesting aspect of their findings: in September 2006, 67% of C. difficile bugs in one location were found to be antibiotic-resistant, while in February 2013, only around 3% were found to be resitant; this highlights the before and after effects of antibiotic restriction efforts. The researchers note the international importance of their findings and hope that doctors around the world will consider the results of this study when prescribing antibiotics.