African 'sniffer' rats used to develop TB breath test

Health researchers from the University of Otago Christchurch are developing a unique breath test for tuberculosis (TB) – a disease that continues to kill more than two million people every year world-wide and is again becoming more prevalent in developed countries like New Zealand.

Monday 24 March is World TB Day, to draw attention to this serious international health problem.

Scientists from the Department of Pathology are about to visit Tanzania to progress investigation into a novel method of diagnosing TB using a type of large African "sniffer" rat, the Giant Gambian rat.

In a recent study, published in the international journal 'Tuberculosis', the researchers describe the discovery of a number of volatile bio-markers, which could be used to identify TB much more quickly using a breath test, rather than current laboratory-based tests.

Scientist Dr Mona Syhre says: "I'm using Giant Gambian rats to test our lab results. The rats are a robust real life test of these potential biomarkers for TB because they are trained to detect TB positive human sputum samples. We're going to see if the rats do in fact sniff the bio-markers we've discovered."

The exciting results are supported by a $50,000 Proof of Concept grant from the University of Otago's commercialisation arm, Otago Innovation Limited. The grant was awarded by a judging panel that included leading venture capitalists from New Zealand and overseas.

Otago Innovation Commercialisation Manager David Christensen says the aim of the Proof of Concept grant is to encourage researchers to think about possible commercial applications of their research, including what an end product or service would look like, and who would buy it.

"This research is ground-breaking because, for the past 100 years, it has been a long process to confirm if someone actually has TB or not. It is done firstly by the direct microscopic examination of sputum specimens, and then further culturing of bacteria in the laboratory to confirm the initial diagnosis – a process which can take up to two months to get a clear result," Mr Christensen says.

Dr Syhre and her colleague, infectious diseases specialist Professor Steve Chambers, have made it their goal to find a quicker, cheaper and simpler breath test, as TB still infects around nine million people every year and is the leading cause of death for people with HIV/AIDS.

"If successful this will make a huge difference in speeding up diagnosis and treatment," says Professor Chambers.

Following the African rat test, the next step will be a clinical trial, arranged through Otago's newly-appointed Chair of International Health, Professor Philip Hill and in collaboration with the Medical Research Council in Gambia using local TB patients. The aim will be to further validate the lab and rat results and then progress to a larger study and development of the breath testing technology for commercial application.

"We're very excited about the progress so far and the prospects for these studies. This is a prime example of how laboratory-based health research can provide new directions for innovation and have direct health benefits," says Professor Chambers.

This research has also been funded by the Health Research Council and Lotteries Health Research.