Swab The Throat And The Nose? The Argument Over The Best Way To Test For SARS-CoV-2

Swab the throat or the nose? The argument over the best way to test for SARS-CoV-2. As COVID-19 continues to pose difficulties, experts and health officials have been considering the most effective approach to antigen testing for asymptomatic individuals. The FDA recently updated its information, recommending that people take rapid antigen tests three times over a span of five days to be sure of a negative result for COVID-19. However, the question of whether to use nasal swabs alone or to combine them with throat swabs remains a subject of clinical argument and ongoing research.

The Reasoning Behind Throat Swabs

Chemist Rustem Ismagilov, PhD, from the California Institute of Technology's Jacobs Institute for Molecular Engineering for Medicine, has suggested that infected people may take longer to test positive with nasal swabs because the initial viral loads of SARS-CoV-2 are higher in the throat. This finding has sparked interest in using throat swabs to improve early detection of SARS-CoV-2 and it may be the best way to test for SARS-CoV-2.

Mixed Findings and Recommendations

While some studies have shown that combining throat and nasal swabs can increase test sensitivity, other research discoveries have been inconclusive. Particularly, the FDA has not authorized any rapid tests that involve throat swabs as of December 2022.

Countries like Canada, especially in the provinces of Newfoundland and Labrador, Nova Scotia, Ontario, and Prince Edward Island, as well as Israel, and the UK's National Health Service, have suggested or employed throat and nose swab combination testing for improved precision.

The Research Divide Created Over The Best Way To Test For SARS-CoV-2

Several studies have explored the efficiency of throat swabs alongside nasal swabs in detecting COVID-19:

The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies at Emory University conducted research on symptomatic people and found no significant improvement in diagnostic performance from throat swabs.

A study in San Francisco using the BinaxNOW rapid antigen test showed a marginal 4% increase in detection with throat swabs, which some researchers deemed not worth the extra effort.

Ismagilov's research on early-stage Omicron infection showed potential benefits in combining specimens from the throat and saliva to detect infections at an earlier stage.

Nova Scotia researchers using the Abbott Panbio rapid antigen test found that combining nasal and throat swabs detected more cases compared to using them alone.

Waiting for Validation

While some believe that adding throat swabs could be useful, the FDA has voiced concerns about reduced test sensitivity. Since rapid antigen tests in the US have been confirmed only with nasal swabs, there is a lack of motivation for manufacturers to explore the safety and effectiveness of adding throat swabs. The FDA could potentially order manufacturers to validate their tests using both throat and nasal swabs, but it remains uncertain when this could happen or if it will.

Unanswered Questions

Several significant questions have yet to be answered regarding throat swabbing for COVID-19 testing:

Could a sample taken from the throat affect the test results, especially considering the differences in chemistry between throat and nasal samples?

How might eating, drinking, or smoking before throat swabbing affect the accuracy of the test?

Could swabbing the throat introduce undesirable microbes into the nasal sample, and does this pose any risks?

Can people effectively swab their throat to acquire a good sample, and can the process be easily translated for at-home use?

So, What Is The Best Way To Test For SARS-CoV-2

While combining nasal and throat swabs may enhance the sensitivity of rapid antigen tests, there is currently no evidence supporting the use of throat swabs alone. As the debate continues, researchers and health authorities strive to find the most effective testing strategies for early COVID-19 detection.