Tag Archives: Antibiotics and Clostridium difficile

Antibiotics; The Main Source Of C. diff. Epidemic Found Through Most Recent UK Study


As published by

University of Leeds  UK


Restricting the use of a common antibiotic was more important than a high profile ‘deep clean’ of hospitals in massively reducing UK antibiotic resistant Clostridium difficile, a major study found.

“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.”


The study concluded that overuse of antibiotics like ciprofloxacin led to the outbreak of severe diarrhea caused by Clostridium difficile (C.diff) that hit headlines from 2006 onward. 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 program 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 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 hand-washing 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 analyzed 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 other countries.”

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.

Further information:  Source:

Contact Sophie Freeman in the University of Leeds

press office on 0113 343 8059 or email s.j.freeman@leeds.ac.uk


Observational Study Of 200,000 Patients Suggests That Hospital Beds Occupied From Previous Patients Increase C.diff. Risk

More than 200,000 patients studied

The observational study, which was conducted at four hospitals in New York City, examined more than 100,000 pairs of patients who sequentially occupied a given hospital bed at one of the facilities from 2010 to 2015.

Patients were excluded from the study if they developed CDI within 48 hours of admission, or if the prior hospital bed occupant was in the bed for less than 24 hours. The intent of the study was to determine whether antibiotic treatment in the initial bed occupant had any impact in CDI rates in subsequent patients.

Overall, there were 576 pairs in which the second hospital bed patient developed CDI within 2 to 14 days of admission—0.57% of the total number of patient pairs observed. The patients who developed CDI were more likely to have traditional CDI risk factors, such as older age, increased creatinine, and decreased albumin.

But the cumulative incidence of CDI was higher when the prior bed occupants had been treated with antibiotics (0.72%) than when they received no antibiotics (0.43%). In the final analysis, CDI was 22% more likely in patients who occupied a bed in which the prior occupant received an antibiotic.

In fact, when researchers considered other potential risk factors for CDI in the prior bed occupants—including treatment with acid-suppression medications and immune suppressants—antibiotic use was the only factor associated with increased risk for CDI in subsequent patients. And the association remained after the researchers excluded the patient pairs in which the prior patient had recent CDI.

Antibiotics add to colonization pressure

The findings add another layer to our knowledge of how antibiotics can increase susceptibility to CDI, which causes an estimated 500,000 illnesses and 

Approximately 29,000 patients died within 30 days of the initial diagnosis of C. difficile.  Of those, about 15,000 deaths were estimated to be directly attributable to C. difficile infections (CDI) a year in the United States.

It’s already well established that treating patients with antibiotics increases risk for CDI by eliminating the good bacteria that keep C difficile in check or increasing bacteria that facilitate it. Previous studies have shown that antibiotic prescribing in individual hospital wards and in hospitals in general can also be associated with increased C difficile risk.

This study, though it only demonstrates a correlation, shows how antibiotics given to other patients may affect the local microenvironment and add to colonization pressure.

“In patients colonized by C difficile, antibiotics may promote C difficile proliferation and the number of C difficile spores that are shed into the local environment,” the authors write. “In turn, this may result in a higher environmental burden of C difficile and greater risk for acquisition and infection in future patients who share the same environment.”

Promoting C difficile proliferation and shedding is significant, the authors add, because            C difficile spores can persist in hospital room surfaces for months +  and are easily transferred from patient to patient.

Because C difficile can spread so quickly and stronger strains are emerging, the Centers for Disease Control and Prevention have labeled the bacteria an urgent public health threat. The White House National Action Plan for Combating Antibiotic-Resistant Bacteria has set a goal of reducing CDI by 50% by the year 2020.


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