Experts clear way for tests to defeat deadly hospital bug

About 3,000 people die in hospitals in the UK each year from the bacterial infection Clostridium difficile (C-diff). The complaint, which affects the digestive system, is most common in patients treated with antibiotics for other infections.

Now a study led by experts from Leeds University has compared the two gold-standard tests for the infection, examining 12,000 samples from patients at four centres including hospitals in Leeds.

The research found patients with samples testing positive using one test were almost twice as likely to die within 30 days than those testing positive using the alternative method. The findings mean tests which detect the presence of C-diff toxin in samples are the most reliable indicators of the infection.

Microbiologist Prof Mark Wilcox, of Leeds University, who also works at the city’s hospitals and is the C-diff lead for Public Health England, said: “The diagnosis of C-diff has become a complicated area with lots of alternative tests, and there has been considerable uncertainty about which are the best tests to use.

“This is a landmark study not only because of its size, but also because we followed what happened to patients. This meant we have been able to show confidently which are the best tests to use to diagnose C-diff. C-diff cases in the NHS have decreased markedly in number since their peak in 2007-08 but reliably diagnosing C-diff is a crucial way forward to continuing to fight this infection.”

The research team says the findings highlight the importance of using appropriate tests to diagnose the infection, especially as it is not possible to diagnose it using laboratory tests.

Treating patients for C-diff and preventing the spread of infections in hospitals relies on accurately identifying who has the infection, but also who may transmit the bug. The study identified a way of using a combination of tests to identify who has C-diff and who could be at risk of spreading it.

The research has already been used as a basis for new NHS guidelines on diagnosing C-diff. The findings are published online today in the journal Lancet Infectious Diseases. The study was funded by the Department of Health and the former Health Protection Agency.