Game Changers: Scientists in China Develop Rapid Breath Test for COVID-19

Breathalyzer tests capable of rapid detection of SARS-CoV-2 would go a long way in simplifying and broadening access to coronavirus screening testing. Now comes word that a team of researchers in China has developed a new breathalyzer that can detect the virus in five to 10 minutes that requires only that test subjects exhale into a bag for 30 seconds.

The Diagnostic Challenge

Most of the currently available tests for detecting the SARS-CoV-2 virus rely on tissue specimens that must be collected by throat or nasal swabs. As a result, developing a test methodology to eliminate swabbing and simplify sample collection has become a focus for a growing number of scientists and laboratory companies around the world.

While saliva testing currently seems to offer the most promise, progress is also being made in breathalyzer applications capable of using the volatile organic compounds (VOCs) a patient exhales to detect the virus. There are 12 signal breath-borne VOCs that can be used as “fingerprints.”

The Chinese Rapid Breath Test

The new rapid breath test, which was reported by the English-language Chinese newspaper Global Times, is based on a study conducted by scientists from the Laboratory of Environmental Simulation and Pollution Control of Peking University and Chaoyang district’s Center for Disease Control and Prevention in Beijing.

The researchers evaluated exhalations of 74 COVID-19 patients, 30 patients with other respiratory infections and 87 healthy people with no infections. They detected higher levels of propanol in the exhaled breath of the former two groups than in the healthy subjects. They also found that breath-borne acetone was significantly lower for COVID-19 patients than for those with other respiratory infections.

Based on the 12 signal VOCs, they created an algorithm. They then verified the algorithm, finding that its accuracy ranged from 91 percent to 100 percent. They concluded that the test is not only accurate for detecting but also differentiating COVID-19 infections from other respiratory infections.

Plans to Deploy the Breath Test

In addition to its speed and accuracy, the breath test offers advantages to current COVID-19 antigen tests by eliminating the need for swabs and reagents. The test is also cheap, reportedly costing 10 yuan ($1.50), as opposed to the 80 yuan ($12) price tag for molecular nucleic acid tests.

Further data and validation tests may be needed before the rapid breath test can be deployed on a widespread basis for COVID-19 screening. But hopes are high that validation is imminent and that the test will be ready in time for use at the Beijing Winter Olympics, which are scheduled to begin on Feb. 4, 2022.

Takeaway

There are also several projects in the US to develop handheld breathalyzer devices using VOC-based detection that can be easily deployed in factories, airports, grocery stores, and businesses of all sorts to rapidly screen for active infections. That includes a NASA project called the “E-Nose.” (See Diagnostic Testing & Emerging Technology, May 22, 2021).