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Infectious agent antigen detection by immunoassay with direct optical (ie, visual) observation; severe acute respiratory syndrome coronavirus 2 (sars-cov-2) (coronavirus disease [covid-19])

CPT4 code

Name of the Procedure:

Infectious Agent Antigen Detection by Immunoassay with Direct Optical (Visual) Observation for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), also known as COVID-19 Antigen Test.


This procedure involves a test that detects parts of the virus causing COVID-19 from a sample taken, usually from the nose or throat. The test uses antibodies to bind to viral antigens and can be seen with the naked eye.


The test is used to determine if a person is currently infected with SARS-CoV-2. The goal is to rapidly identify infected individuals to manage and control the spread of COVID-19.


  • Symptoms such as fever, cough, shortness of breath, and loss of taste or smell.
  • Recent contact with a confirmed COVID-19 case.
  • Requirement for testing before travel or surgery.


  • No specific preparation required.
  • Patients should inform their healthcare provider of any nasal issues or recent nosebleeds.

Procedure Description

  1. A sterile swab is inserted into the nasal cavity or throat to collect a sample.
  2. The swab is placed in a solution that releases viral antigens.
  3. The specimen is applied to a test strip containing antibodies specific to SARS-CoV-2.
  4. If viral antigens are present, they bind to the antibodies and produce a visible line or spot that can be observed directly.

Tools and Equipment:

  • Sterile swabs
  • Antigen test kit
  • Solution for antigen release
  • Test strip with antibodies


The test typically takes about 15-30 minutes to produce results.


The procedure can be conducted in a variety of settings including hospitals, outpatient clinics, urgent care centers, and even at home with a self-test kit.


Healthcare professionals such as nurses, medical assistants, or trained personnel.

Risks and Complications

  • Mild discomfort or irritation in the nasal or throat area.
  • Rarely, a false negative or false positive result can occur.
  • Misinterpretation of results if not conducted properly.


  • Rapid diagnosis of current COVID-19 infection.
  • Helps in timely isolation to prevent the spread of the virus.
  • Quick results, typically within 15-30 minutes, facilitating prompt decision-making.


  • No specific recovery period required.
  • Patients can resume normal activities immediately after the test.
  • Follow-up instructions based on the test result (e.g., isolation if positive).


  • PCR (Polymerase Chain Reaction) test: More accurate but takes longer and requires lab facilities.
  • Antibody tests: Detect past infection but not suitable for diagnosing current infection.
  • Pros and cons: Antigen tests are faster and more accessible, while PCR tests are more sensitive and accurate.

Patient Experience

  • Mild discomfort during sample collection, similar to a tickling or burning sensation in the nose or throat.
  • Rapid test with waiting time for results being short.
  • Minimal pain, manageable with standard over-the-counter pain relief if necessary.

Medical Policies and Guidelines for Infectious agent antigen detection by immunoassay with direct optical (ie, visual) observation; severe acute respiratory syndrome coronavirus 2 (sars-cov-2) (coronavirus disease [covid-19])

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