Driven by the emergence of new hypervirulent strains, Clostridium difficile infections (CDIs) have been on the rise since the early 2000s, and have overtaken methicillin-resistant Staphylococcus aureus (MRSA) as the most common healthcare-acquired superbug. However, in England the use of antibiotic stewardship has helped to reverse this trend over the last 10 years, and now one group of researchers thinks they know why.
Since the introduction of policies designed to improve infection control and restrict antibiotic use in 2006, the incidence of CDIs has dropped by roughly 80%, according to Public Health England. In comparison, it has been estimated that other countries may have seen a rise in incidence of 16% over the same time period.
So what exactly was so successful about the antibiotic stewardship program?
A recent study in Lancet Infectious Diseases suggests that restrictions on fluoroquinolone use might explain the observed drop in CDI incidence.
During the study, researchers took local and national data on C. difficile incidence and antibiotic prescribing practices, and compared them to genomic sequences of C. difficile isolates during the same time period. They found that the decline in CDI was driven by a drop in the prevalence and transmission of fluoroquinolone-resistant strains of C. difficile. In comparison, there was very little change to transmission of fluoroquinolone-susceptible strains over the same time period.
From their findings, the authors concluded that the restrictions on fluoroquinolone use appear to explain the decline in C. difficile infections in England, and suggest that antibiotic stewardship should be at the center of any program to control CDI.
One challenge when implementing a unilateral antibiotic stewardship program is achieving a high level of compliance from physicians, and although the centralized National Health Service in England could exercise additional control over antibiotic stewardship in hospitals, there may still be significant opportunities in improving compliance by primary care practitioners.
It remains to be determined whether reduced fluoroquinolone usage was the only contributing factor to the drop in CDI prevalence seen in England. It will therefore be interesting to see if similar antibiotic stewardship programs aiming at replacing fluoroquinolones with other treatment options can result in similar outcomes in other countries. For example, in Italy, where fluoroquinolone-resistant C. difficile strains are known to be prevalent, antibiotic stewardship might provide an effective approach to CDI control and prevention.