# 5695
Based on the number of news stories published overnight – and their `forward looking’ headlines - you’d think the study that appeared in yesterday’s Journal of Breath Research was the scientific discovery of the year.
A few examples:
Swine flu breath test would 'save thousands from having needless vaccines' – Daily Mail
Future Swine Flu Vaccination Shortages Could Be Reduced By Breath Test – Medical News Today
Now, breath test to diagnose H1N1 infection – New Kerala
The actual research isn’t quite as far advanced as these headlines might lead the reader to believe.
A far more balanced (and realistic) report comes from Lauren La Rose of the Canadian Press.
H1N1 breath test could help ID those infected with flu virus, study suggests
In it, one of the authors of the report is quoted as calling this research "rather preliminary," and that he views it mainly as a “proof of the concept” that monitoring chemical components in the breath could be used to determine vaccine response, or perhaps even infection status.
The study itself is available online.
Effect of the influenza A (H1N1) live attenuated intranasal vaccine on nitric oxide (FENO) and other volatiles in exhaled breath
A Mashir, K M Paschke, D van Duin, N K Shrestha, D Laskowski, M K Storer, B Yen-Lieberman, S M Gordon, M Aytekin and R A Dweik
The article is (temporarily) available for free (registration required), and a press release is available here.
The gist of the study is that researchers inoculated a small (n=9) number of subjects with the live attenuated (Flumist) H1N1 vaccine, and then measured the chemical components of their exhaled breath over a period of 7 days.
The found elevated levels of nitric oxide (NO) – which has previously been linked to influenza and viral infection – on day 3 in all the test subjects. Another compound - isoprene – was detected at elevated levels on day three as well.
While these elevated levels appear to be connected to the replication of the live-attenuated H1N1 virus in the lungs, exactly how and why they are produced isn’t known.
One of the authors of the study, Professor Raed Dweik is quoted in the press release as saying:
"This study adds to the growing evidence for the utility of breath analysis in medical diagnostics. More work still needs to be done, however, to identify the specific compounds that change in response to vaccination and to find the biologic link between those compounds and the host response to the vaccine or the actual disease."
Which - while admittedly a fascinating line of research - is a far cry from today’s headlines that boldly suggest that scientists have invented a test can identify H1N1 infections.
Not to rain on anyone’s parade, but in order for a breath test to be able to identify who was infected by a specific influenza virus, the test would have to be able to differentiate between different viral infections.
And thus far, that ability has not been demonstrated.
Earlier this week, in BMC Study: A Crowded Viral Field, we looked at viral screening results during the opening months of the 2009 pandemic in Scotland.
They found that only 9% of those diagnosed with the H1N1 virus (based on clinical & epidemiological criteria) actually tested positive for the virus.
Many others were infected with rhinovirus (8.9%), parainfluenza 1 (1.9% ) and 3 (4.1%), and adenovirus (3.5%). In the majority of cases, the cause of the illness could not be identified.
A breathalyzer test that could identify who was already infected with a specific virus would be a major coup, of course. And this line of research might someday lead us there.
But despite this morning’s breathless headlines, we aren’t there yet.
