Leeds: The study concluded that overuse of antibiotics like ciprofloxacin led to the outbreak of severe diarrhoea caused by Clostridium difficile (C.diff) that hit headlines from 2006 onwards. The outbreak was stopped by substantially reducing use of ciprofloxacin and related antibiotics. 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, leaving the way clear for rapid growth of resistant C. diff. Concerns about hospital 'superbugs' which had become resistant to common antibiotics resulted in the announcement of a programme of “deep cleaning” and other infection control measures in the NHS in 2007.
The study, by the University of
Leeds, University of Oxford and Public Health England and published today in
The Lancet Infectious Diseases, found that cases of C. diff fell only when
fluoroquinolone use was restricted and used in a more targeted way as one part
of many efforts to control the outbreak.
The restriction of fluoroquinolones
resulted in the disappearance in the vast majority of cases of the infections
caused by the antibiotic-resistant C. diff, leading to around an 80% fall
in the number of these infections in the UK (in Oxfordshire approximately 67%
of C. diff bugs were antibiotic-resistant in September 2006, compared to
only approximately 3% in February 2013).
In contrast, the smaller number of
cases caused by C. diff bugs that were not resistant to fluoroquinolone
antibiotics stayed the same. Incidence of these non-resistant bugs did not
increase due to patients being given the antibiotic, and so were not affected
when it was restricted.
At the same time, the number of
bugs that were transmitted between people in hospitals did not change. This was
despite the implementation of comprehensive infection prevention and control
measures, like better handwashing and hospital cleaning in this case.
The study’s authors therefore
conclude that ensuring antibiotics are used appropriately is the most important
way to control the C. diff superbug. The authors note that it is important
that good hand hygiene and infection control continues to be practiced to
control the spread of other infections.
The study analysed data on the
numbers of C. diff infections and amounts of antibiotics used in hospitals and
by GPs in the UK.
More than 4,000 C. diff bugs also
underwent genetic analysis using a technique called whole genome sequencing, to
work out which antibiotics each bug was resistant to.
Co-author Derrick Crook, Professor
of Microbiology, University of Oxford said: “Alarming increases in UK hospital
infections and fatalities caused by C. diff made headline news during the
mid-2000s and led to accusations of serious failings in infection control.
“Emergency measures such as ‘deep
cleaning’ and careful antibiotic prescribing were introduced and numbers of C.
diff infections gradually fell by 80% but no-one was sure precisely why.
“Our study shows that the C.
diff 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. diff 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. diff 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.
“These findings are of
international importance because other regions such as North America, where
fluoroquinolone prescribing remains unrestricted, still suffer from epidemic
numbers of C. diff infections.”
Co-author Prof Mark Wilcox,
Professor of Microbiology, University of Leeds, said: “Our results mean that we
now understand much more about what really drove the UK epidemic of C. diff
infection in the mid-2000s.
“Crucially, part of the reason why
some C. diff strains cause so many infections is because they find a way to
exploit modern medical practice.
"Similar C. diff bugs that affected
the UK have spread around the world, and so it is plausible that targeted
antibiotic control could help achieve large reductions in C. diff infections in
The funding for the study came from
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.
Journalists can contact Sophie Freeman in the University of Leeds press office on 0113 343 8059 or email firstname.lastname@example.org
The research paper is available here