C. difficile increases risk of death six-fold in patients with inflammatory bowel disease

IBD, consisting of Crohn's disease and ulcerative colitis, affects around 240,000 people in the UK and its symptoms include abdominal pain and diarrhea. When sufferers experience a bout of severe symptoms, they often need to be admitted to hospital.

C. difficile bacteria are present naturally in the gut in around two thirds of children and 3 per cent of adults, but they do not cause problems in healthy people. Broad spectrum antibiotics can cause problems by killing harmless bacteria that usually reside in the gut, allowing C. difficile to flourish and produce toxins that cause diarrhea and fever. The infection is rarely fatal in people who are not already severely ill or elderly; a review published in 2010 estimated the overall mortality rate for patients with C. difficile to be 6 per cent.

There have been drives to reduce the spread of infection by improving hospital hygiene and changing antibiotic policies, which have had some success, but there are concerns that high-risk patients are still not adequately protected. Since IBD patients already have inflammation in the gut, they are thought to be especially vulnerable to C. difficile infection, but until now the incidence of infection in these patients in the UK was not known.

In the new study, published in the journal Alimentary Pharmacology and Therapeutics, researchers from Imperial College London and St George's Healthcare NHS Trust examined NHS statistics on patient admissions between 2002 and 2008. After adjusting for differences between the groups, they found that IBD patients who contract C. difficile in hospital are six times more likely to die in hospital than patients who are admitted for IBD alone. In the patients followed in the study, the mortality rate for IBD patients with C. difficile at 30 days was 25 per cent, compared with 3 per cent for patients with IBD alone.

The results also showed that IBD patients with C. difficile also stay in hospital for longer, with a median length of stay of 26 days compared with five days, and are almost twice as likely to need gastrointestinal surgery.

Dr Sonia Saxena, from the School of Public Health at Imperial College London, said: "Hospitals must do everything they can to control infections such as C. difficile. We are asking for these high-risk patients to be screened for C. difficile proactively on admission to hospital so that if they are exposed, they can be diagnosed and treated more quickly."

Dr Richard Pollok, from St George's Healthcare NHS Trust, who was the senior author of the study, said: "At St. George's Hospital, we have seen a 70 per cent reduction in hospital-acquired infections after implementing a range of control measures, such as careful handwashing and reduced use of broad spectrum antibiotics. But we need to do more to protect vulnerable patients such as those with IBD."

The research was supported by the National Institute for Health Research, through the Biomedical Research Centre (BRC) and the Collaboration for Leadership in Applied Health Research and Care (CLAHRC) funding schemes, and the Centre for Infection Prevention and Management funded by the UK Clinical Research Collaboration. Dr Min-Hua Jen, the first author of the study, is supported by HERON Evidence Development Limited.