MMM researchers at Oxford and Leeds, and PHE, have published a major piece of research proving that overuse of antibiotics was the main driver of the C. difficile (C. diff) epidemic that took place in the UK by mid-2000s. In a nutshell, the study published online on 24/1/17 in The Lancet Infectious Diseases, showed that within a group of measures to control the outbreak, restrictions on fluoroquinolone use had the highest impact.
Inappropriate use and widespread over prescribing of fluoroquinolone antibiotics—such as ciprofloxacin—in fact allowed C. diff bugs that were resistant to the drug to thrive, because non-resistant bugs in the gut were killed off by the antibiotic. This left the way clear for rapid growth of resistant C. diff. (See picture below.)
The observations that restriction of fluoroquinolones resulted in the disappearance of the vast majority of infections caused by the antibiotic-resistant C. diff, but did not significantly decrease the number of cases caused by drug-sensitive bugs or the number of bugs that were transmitted between people in hospitals, confirmed the hypothesis that ensuring antibiotics are used appropriately is the most important way to control the C. diff superbug.
The study analysed data on the numbers of C. diff infections and on the amounts of antibiotics used in hospitals and by GPs in the UK. It also whole genome sequenced 4,000 C. diff bugs to work out which antibiotics each bug was resistant to.
Co-author Derrick Crook, from University of Oxford said: “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 study was funded by the UK Clinical Research Collaboration, (Medical Research Council, Wellcome Trust, National Institute for Health Research); NIHR Oxford Biomedical Research Centre; NIHR Health Protection Research Unit in Healthcare Associated Infections and Antibiotic Resistance, University of Oxford in partnership with Leeds University and Public Health England; NIHR Health Protection Research Unit in Modelling Methodology, Imperial College London in partnership with Public Health England; and the Health Innovation Challenge Fund.