Infectious agent antigen detection by immunofluorescent technique; Varicella zoster virus
CPT4 code
Name of the Procedure:
Infectious Agent Antigen Detection by Immunofluorescent Technique - Varicella Zoster Virus (IFAT for VZV).
Summary
This test detects the presence of antigens from the Varicella Zoster Virus (VZV), which causes chickenpox and shingles, using a specialized technique involving fluorescent dyes that bind to viral antigens in a sample.
Purpose
The purpose of this test is to diagnose infections caused by VZV. It helps confirm whether a patient has chickenpox or shingles, which are both caused by the same virus. This information is crucial for proper treatment and management of the infection.
Indications
- Rash or skin lesions that resemble chickenpox or shingles.
- Symptoms such as fever, headache, tiredness, or a painful skin rash.
- Immune-compromised patients with unexplained rashes or suspected VZV infection.
- Monitoring of VZV in pregnant women exposed to the virus.
Preparation
- Patients typically do not require any special preparation.
- Inform the healthcare provider of any medications or supplements being taken.
Procedure Description
- A sample, often a skin swab or fluid from a blister, is collected.
- The sample is placed on a slide.
- Fluorescent-labeled antibodies designed to bind specifically to VZV antigens are applied.
- The slide is examined under a fluorescence microscope.
- If VZV antigens are present, they will glow under the microscope.
Tools: Fluorescence microscope, immunofluorescent dyes, collection swabs.
Anesthesia: Not required.
Duration
The procedure itself takes approximately 15-30 minutes, but results typically take a few hours to a few days, depending on the lab's processing times.
Setting
This test is usually performed in a hospital laboratory or specialized diagnostic lab.
Personnel
- Laboratory technicians or technologists specially trained in immunofluorescence techniques.
- Pathologists or microbiologists may interpret the results.
Risks and Complications
- There is minimal risk associated since the procedure is non-invasive.
- Rarely, there may be minor discomfort or irritation at the sample collection site.
Benefits
- Accurate and rapid diagnosis of VZV infection, allowing for timely treatment.
- Helps avoid unnecessary treatments if the patient's condition is due to another cause.
Recovery
- No recovery time is needed as the procedure is non-invasive.
- Patients can resume normal activities immediately after sample collection.
Alternatives
- Polymerase Chain Reaction (PCR) testing which is highly sensitive and specific for VZV DNA.
- Serological tests to detect antibodies developed in response to VZV.
Pros and Cons:
- IFAT is rapid and provides visual confirmation but may be less sensitive than PCR.
- PCR is highly sensitive but more expensive and requires specialized equipment.
Patient Experience
- Patients may experience slight discomfort during sample collection.
- Generally, the procedure is well-tolerated and quick.
- Results interpretation and treatment decisions will follow once results are available.