Breath test could detect bad microbe

Scientists in New Zealand have devised a breath test for detecting a fungal lung infection. Using gas chromatography and mass spectroscopy, the team detected a substance called 2-pentylfuran in the breath of people infected with Aspergillus fumigatus but not in people presumed to be free of infection.

The achievement stands as the first example of using people’s breath to detect an airborne biomarker of a pathogen in their lungs, says Stephen T. Chambers, a physician at the University of Otago in Christchurch. He presented the work at a meeting of the Infectious Diseases Society of America in San Francisco in October.

A. fumigatus causes infections in people with compromised immune systems. Chambers and his colleagues tested breath from 10 healthy volunteers and four cystic fibrosis (CF) patients whose lungs had been colonized by A. fumigatus. None of the healthy volunteers had detectable 2-pentylfuran in their breath, but all the CF patients did.

A breath test based on the findings would be less invasive than a lung biopsy to diagnose A. fumigatus, Chambers says. The test would be particularly useful for leukemia patients who have received bone marrow transplants, which involve suppression of the immune system, he adds.