Diagnostic strategies for endemic Coronavirus Disease 2019 (COVID-19)

By:
KOST GJ. ARCH PATHOL LAB MED (VOL. 146: 16-25)

The findings in a nutshell

COVID-19 rapid antigen tests generate fast and immediately actionable results. They quickly confirm COVID-19, but weakly rule out infection as their sensitivity is not as high as other testing methods. Test performance depends on the prevalence in the community and testing protocol. The move toward the global endemic phase calls for high quality, low cost and user-friendly testing methods. This research provides a few important recommendations or diagnostic strategies to help us work toward this goal.

Overview of the paper

COVID-19 is moving toward the endemic phase globally, and new COVID variants are spreading rapidly across communities. This emphasises the need for high quality, low cost, readily accessible, user-friendly testing. The article describes some interesting and complex original mathematics and visual logistics for interpreting rapid antigen test performance patterns. These found that the deterioration of performance of these tests appears with increasing prevalence. The key points outlined by this paper are as follows:

• Rapid Antigen Tests (RATs) generate fast and immediately actionable results
• Sensitivity / specificity test results suggest that they quickly confirm COVID-19, but only weakly rule out infection
• Current high prevalence of COVID and the particular testing protocol utilised are suggested to alter test performance
• This study analysed and interpreted COVID RAT performance patterns to determine the influence of prevalence and evaluate repeated testing
• When COVID-19 is highly prevalent across communities, the sensitivity of RATs is limited (risk of not detecting infection when present is higher)

Implications for Australian workplaces

The key take away, evidence-based message from this paper is that dual testing 36 hours apart allows time for the viral load to increase, thus improving the sensitivity of rapid antigen testing. Adopting this testing protocol when using RATs will maximise the sensitivity of the tests to the COVID-19 virus.

To find out more about Diagnostic strategies for endemic Coronavirus Disease 2019 (COVID-19) read the full article here.

More practical RAT tips

Follow this link to an ABC story called ‘Eat or brush your teeth before taking a RAT swab? Here’s why it may affect the results’ for excellent tips to help ensure the accuracy of RATs.

Date published: January 2022