Health & Wellbeing

First COVID-19 breath test authorized for use in United States

First COVID-19 breath test aut...
A patient blows into the device using a plastic straw and results are returned in three minutes
A patient blows into the device using a plastic straw and results are returned in three minutes
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A patient blows into the device using a plastic straw and results are returned in three minutes
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A patient blows into the device using a plastic straw and results are returned in three minutes
The company claims one device can conduct around 160 tests per day
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The company claims one device can conduct around 160 tests per day

The first breath-based COVID-19 test has been issued an emergency use authorization by the U.S. Food and Drug Administration (FDA). The device takes three minutes to return results and has been found to be over 90 percent accurate in detecting positive COVID-19 cases.

The new breath-testing device is from a company called InspectIR and uses gas chromatography mass-spectrometry (GC-MS) to analyze breath samples. Like prior COVID breathalyzer prototypes, the device doesn’t identify the presence of specific viral particles. Instead it’s designed to pick up patterns of volatile organic compounds (VOCs) that have been found to correspond with SARS-CoV-2 infection. In this case the company says a pattern of five specific VOCs can effectively identify positive cases of COVID-19.

A statement from the FDA indicates the emergency use authorization was influenced by the results of a large study composed of almost 2,500 subjects. The research found the test picked up 91.2 percent of positive COVID-19 cases, a metric known as test sensitivity. The specificity of the test was even higher, correctly identifying 99.3 percent of negative cases.

“Today’s authorization is yet another example of the rapid innovation occurring with diagnostic tests for COVID-19,” said Jeff Shuren, from the FDA’s Center for Devices and Radiological Health. “The FDA continues to support the development of novel COVID-19 tests with the goal of advancing technologies that can help address the current pandemic and better position the U.S. for the next public health emergency.”

The company claims one device can conduct around 160 tests per day
The company claims one device can conduct around 160 tests per day

While the FDA’s authorization of InspectIR’s breathalyzer is inarguably a milestone – marking the first approval for a breath-based COVID-19 testing technology in the United States – this particular device is unlikely to be a game-changer in the real world.

The FDA authorization requires the device to be used by trained operators under the supervision of health care providers. Plus, although InspectIR have cleverly engineered the bulky GC-MS equipment into a small case, the device is far from a portable object. The current iteration of the breathalyzer comes in a large luggage-style case.

No price has yet been revealed for the device but the FDA’s authorization statement does indicate very limited production over the coming months. The company reports a production capacity of around 100 units a week. Each unit is said to be able to process around 160 samples a day.

So realistically, the InspectIR breathalyzer is likely to only be sporadically seen at hospitals or mobile COVID-19 testing sites over the next few months. There are, however, plenty of other COVID breath-testing systems in the works looking to make this kind of technology more accessible.

In February, a team of researchers in Singapore demonstrated a small portable COVID-19 breathalyzer that delivers highly accurate results in minutes. That device also relies on detecting unique patterns of VOCs in breath, but instead of using bulky GC-MS systems to analyze samples it looks to a technology called Raman spectroscopy. This kind of sensor technology can be engineered into small, relatively affordable portable devices.

Looking beyond VOC breath patterns to catch COVID-19 cases, a team of researchers in Australia recently presented a prototype device designed to specifically detect SARS-CoV-2 particles in breath samples. Clinical trials are currently underway to validate its accuracy and if successful it could be available later this year.

Source: FDA

3 comments
3 comments
Karmudjun
Awesome! Clearly we need less invasive SARS testing - I can't imagine being nasal & oral swabbed on a regular basis to insure I am not infectious just so I can see people in the workplace! But I still carry a mask everywhere I go and I will not sit with others (inside or outside) without a mask on until this endemic SARS-CoV-2 plague is in limited reruns. We get past one variant and up crops another one. China is growing many new variants as I type this - instead of limiting spread with their lockdowns, they seem to have mega spread! What will happen when those variants hit the US shores? We need this technology rolled out and working!
EH
Thanks for including the sensitivity and specificity numbers. Using Bayes' Theorem (via an online calculator), I computed the odds of a positive test result being correct: If 1% of the tested population has COVID (probably much too high an estimate), there is a 43% chance that the test result is a false positive. For a more realistic 0.1% prevalence rate, there is an 88% chance the result is a false positive. The false negative rates are negligible. Positive tests on the breath test should be confirmed by another method.
EH
A specificity of 99.3% means 7 false positives for each 1000 people tested who do not have COVID. If the true prevalence rate of COVID among those tested is also 7 in 1000, then if the sensitivity of the test were perfect, then there would be 7 true positive test results per 1000 people. So after ~1007 tests, half of the positive test results would be wrong. If the prevalence rate of active COVID cases is less than 0.7%, most of the positive test results will be false positives.

That's the intuitive explanation, the exact numbers can be found using Bayes' Theorem, or an online specificity-sensitivity calculator. Unless the true COVID prevalence in the tested population is quite high, several percent, then there will be more than a 10% chance that a positive test result is a false positive. So positive breath test results will need to be confirmed by PCR tests in many situations, particularly for asymptomatic subjects in populations without ongoing serious outbreaks. (The PCR tests have their own sensitivity and specificity rates which depend largely on the number of PCR cycles the test uses for amplification - a higher cycle number makes the test more sensitive but less specific.)