SARS-CoV-2 rapid antigen test: High sensitivity to detect infectious virus

Area of Science:

• Infectious Diseases
• Diagnostic Microbiology
• Public Health

Background:

• The COVID-19 pandemic necessitates rapid, cost-effective, and point-of-care diagnostic tools for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
• Effective diagnostics are crucial for limiting disease transmission.

Purpose of the Study:

• To evaluate the performance of two rapid antigen immunochromatographic tests for detecting infectious SARS-CoV-2.
• Assessing the Abbott Panbio™ COVID-19 Ag Rapid Test and the Zhejiang Orient Gene/Healgen Biotech Coronavirus Ag rapid test cassette.

Main Methods:

• Evaluation of nasopharyngeal samples from symptomatic individuals using real-time PCR for SARS-CoV-2 RNA analysis.
• Testing 156 PCR-positive and 130 (Panbio) / 176 (Orient Gene) PCR-negative samples.
• Subgroup analysis based on Ct-values and viral cultivation on Vero cells.

Main Results:

• Overall sensitivity and specificity: Panbio (71.8%, 100%), Orient Gene (79.5%, 74.4%).
• High sensitivity (>88%) for samples with Ct-values <25 and infectious virus presence (Panbio: 94.1%, Orient Gene: 97.1%).
• Both tests detected <50 picogram nucleocapsid protein; no infectious virus found with Ct-value >27.

Conclusions:

• Rapid antigen tests, particularly the Panbio test, show potential as valuable tools for identifying contagious individuals during the pandemic.
• The tests are effective in detecting infectious SARS-CoV-2, especially in early stages of infection.