Table of Contents

1. Introduction
2. What is an Antigen Test?
3. How Antigen Tests Work
4. Advantages and Limitations
5. Immuno Company Solutions
6. References

Introduction

Antigen tests play a pivotal role in modern diagnostics by rapidly identifying active infections. Predominantly used for detecting viral infections, such tests have garnered significant attention during the COVID-19 pandemic. Understanding their mechanism and application helps in assessing their utility in public health.

What is an Antigen Test?

An antigen test is a diagnostic tool used to detect specific proteins, known as antigens, on the surface of pathogens like viruses and bacteria. By identifying these proteins, antigen tests can rapidly determine the presence of an infectious agent.

How Antigen Tests Work

Antigen tests are commonly designed as lateral flow assays, similar to home pregnancy tests. The process involves:

1. Sample Collection: A swab is used to collect a sample from the nasal cavity or throat.
2. Sample Application: The sample is applied to a test strip containing antibodies that bind to the target antigen.
3. Signal Detection: A visible line appears on the test strip if the antigen is present. The intensity of the line correlates with antigen concentration.

Performance Metrics:

• Sensitivity: Typically ranges from 50-80%
• Specificity: Generally exceeds 90%
• Time to Result: Approximately 15-30 minutes

Advantages and Limitations

Advantages

• Rapid results enhance timely decision-making.
• Cost-effective compared to molecular tests.
• Simple procedure suitable for point-of-care settings.

Limitations

• Lower sensitivity compared to PCR tests.
• Potential for false negatives, especially in low viral load scenarios.
• Best used in conjunction with other diagnostic methods for confirmation.

Immuno Company Solutions

Several companies provide antigen test solutions tailored for different pathogens:

• Company A: Offers tests with a sensitivity of 78% and specificity of 95% for SARS-CoV-2, priced at $5 per test.
• Company B: North American leader in antigen testing technology with 82% sensitivity and over 98% specificity for influenza A and B viruses.

References

1. World Health Organization. (2020). Antigen-detection in the diagnosis of SARS-CoV-2 infection using rapid immunoassays. Retrieved from WHO official website.
2. Centers for Disease Control and Prevention. (2021). Interim Guidance for Antigen Testing for SARS-CoV-2.
3. Scientific Reports on Antigen Test Efficacy, Journal of Clinical Microbiology, 2020.