Non-invasive breath test for pulmonary tuberculosis
26 February 2010
A new point-of-care test can detect active pulmonary
tuberculosis by analysing volatile compounds in the breath, according to
an international study to be published in the journal Tuberculosis.
The breath test may offer a new way to detect tuberculosis, a
major cause of death, especially in developing countries. Doctors
often have difficulty diagnosing the disease because current tests
such as a chest X-ray or sputum culture are expensive and often
generate false-positive or false-negative results.
The United States Air Force recently awarded US company Menssana
Research a contract to evaluate a new point-of-care breath test for
pulmonary tuberculosis, studying patients in Africa, Great Britain
and the Philippines. If successful, a patient could learn within
minutes whether they are infected with tuberculosis.
The National Institutes of Health previously funded a multicenter
international study to validate the breath test for pulmonary TB in
San Diego, London, and two sites in the Philippines and Mexico.
"The breath test was 85% accurate in detecting patients with
active pulmonary tuberculosis," said Dr Michael Phillips, developer
of the breath test and CEO of US company Menssana Research. "The
breath test appears to detect volatile organic compounds
manufactured by the infecting organism, Mycobacterium
tuberculosis, that causes the disease. The breath test detects
a signal from Mycobacteria in the lungs, which is why it's
probably a better test than skin tests or a blood test for
tuberculosis that measure the body's immune response to infection."
Another advantage is that the breath test is safe, painless, and
non-invasive, as a patient breathes gently for two minutes for a
sample collection.
Dr Phillips hopes that physicians and patients will eventually
consider a breath test in the same way as we now think of a chest
x-ray or a blood test: as an inexpensive and convenient screening
test which can detect several diseases in their earliest and most
treatable stages.
Menssana Research says it is currently developing breath tests
for several other diseases, including lung cancer, breast cancer,
and ischemic heart disease. The US FDA previously approved the
company's Heartsbreath test for heart transplant rejection.