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Cliff the Beagle sniffs out C. diff
14th December 2012 -- A two year old beagle named Cliff may hold the key to potentially preventing C. diff infection.
Researchers in the Netherlands taught Cliff to sniff out the intestinal bacteria Clostridium difficile (C. difficile or C. diff) in stool samples from infected patients and even from the patients themselves.
In 2011 there were 2,053 deaths involving C. diff in England and Wales.
C. diff is commonly spread in hospitals and long-term care homes, causing diarrhoea that can be mild to life-threatening.
The hope is that other dogs can be trained to identify the infection far faster than it is found through current tests, preventing potentially deadly outbreaks in these settings.
"This study proves the concept, but we have to confirm that this approach will be useful in the real-world setting," says researcher Dr Marije Bomers of the VU University Medical Centre in Amsterdam in the Netherlands.
Cliff on C. Diff patrol: Image BMJ
Dogs can smell better
Older adults who have been admitted to hospital and have recently had a course of antibiotics are most at risk of C. diff infections.
Early detection can prevent the spread in hospitals and other care centres, but current tests can take anywhere from two days to up to a week to confirm infection, Dr Bomers says.
She says the idea for the study came from the observation that the diarrhoea of patients with C. diff infections has a particular smell that she and her colleagues could sometimes detect.
It occurred to them that if humans could smell the infection some of the time, then dogs, with their superior sense of smell, should be able to smell it all the time.
To test the theory, they enlisted psychologist and dog trainer Hotsche Luik, who is also Cliff's owner.
Over two months, the beagle was taught to identify the C. diff toxin in smaller and smaller quantities and in different samples, including human stool.
During one test, he correctly identified 50 of 50 C. diff positive stool samples and 47 of 50 negative samples.
In a separate test, he was taken to two hospital wards to examine his ability to sniff out the infection in patients.
He correctly identified C. diff in 25 of 30 infected patients. He also identified no infection in 265 of 270 non-infected patients.
He completed this task in one of the wards in less than 10 minutes.
New type of 'pet scan'
The researchers write in the BMJ that highly trained dogs like Cliff may one day patrol hospital wards to seek out C. diff infection.
However, experts say large hospitals may hold too many distractions for a superbug sniffing dog.
Detecting superbugs is just one of many medical uses for a dog's nose being researched. Dogs are being trained to detect prostate and bowel cancers.
Diabetic Hypo Alert Dogs are trained to detect both hypoglycaemia and hyperglycaemia. They can warn their owners by licking or pawing them, even before symptoms arise.
Additional UK reporting by Tim Locke