SARS-CoV-2/COVID-19 Testing: The Tower of Babel

Area of Science:

• Public Health
• Infectious Disease Epidemiology
• Diagnostic Testing

Background:

• Testing is a cornerstone of the public health response to the SARS-CoV-2 (COVID-19) pandemic.
• The accuracy and utility of testing programs are influenced by both the type of tests used and the specific context of their application.

Purpose of the Study:

• To describe developed SARS-CoV-2 testing methods and strategies.
• To evaluate pooled testing and rapid antigen tests for population-wide screening.
• To analyze the impact of pre-test probability on the predictive values of rapid antigen tests.

Main Methods:

• Description of various SARS-CoV-2 testing methods and strategies.
• Focus on pooled testing (split-pooling) and rapid antigen testing for population-wide applications.
• Analysis of the accuracy of split-pooling and the predictive values of rapid antigen tests under different pre-test probability scenarios.

Main Results:

• Split-pooling demonstrates higher sensitivity and requires fewer tests compared to individual testing when negative results are retested.
• Rapid antigen tests show utility in low pre-test probability scenarios; a negative result can help rule out infection, while a positive result necessitates confirmatory molecular testing.

Conclusions:

• Choosing the appropriate SARS-CoV-2 test requires consideration of testing program goals and context, not solely test performance.
• Pooled testing strategies are recommended for population-wide screening.
• Weekly rapid antigen testing is advised for periodic monitoring in low-prevalence populations.