What is the Varicella Zoster (DNA) test?

The Varicella Zoster (DNA) test is a PCR-based test that detects the presence of varicella zoster virus (VZV) genetic material in a sample. VZV is the virus responsible for chickenpox (primary infection) and shingles (reactivation).

PCR testing is highly sensitive and can confirm active infection even at early stages or when symptoms are atypical. Samples are usually taken from a skin lesion, blister, or swab, depending on presentation.

This test confirms active viral replication rather than past exposure.

Why do I need a Varicella Zoster (DNA) test?

Symptoms of VZV infection can overlap with other viral or skin conditions. PCR testing provides definitive confirmation.

You may need this test if you experience:

• Painful blistering rash
• Localised rash following a nerve pathway
• Suspected shingles
• Atypical or mild rash
• Complications involving eyes or face
• Symptoms in immunocompromised individuals
• Need to distinguish shingles from herpes simplex
• Unclear rash diagnosis

Accurate diagnosis supports timely clinical management and infection control decisions.

Benefits of the test

1. Confirms active VZV infection
   Detects viral DNA directly.
2. Highly sensitive and specific
   PCR is the gold standard for diagnosis.
3. Differentiates from other viruses
   Helps distinguish shingles from herpes simplex.
4. Useful in early or atypical cases
   Detects virus before classic features develop.
5. Supports clinical decision-making
   Confirms cause of rash or neurological symptoms.
6. Suitable for immunocompromised patients
   Important where symptoms may be subtle.
7. Rapid and accurate testing
   Provides reliable results from small samples.
8. Reduces diagnostic uncertainty
   Avoids unnecessary or incorrect treatment.

Step-by-step: How we offer testing

Clinic-based testing (UK-wide)

• Choose your nearest UK clinic
• Lesion or swab sample collected by a clinician
• Sample sent to the laboratory for PCR analysis
• Results issued once testing is complete

Home or hotel visit (+£60, UK-wide)

• Sample collected at home or hotel where appropriate
• Lesion or swab sample obtained
• Sample securely transported to the laboratory

Your results explained

Negative result

• Varicella zoster DNA not detected
• UK standard: Negative
• No evidence of active VZV infection

Positive result

• Varicella zoster DNA detected
• UK standard: Positive
• Confirms active chickenpox or shingles infection

Results should be interpreted alongside clinical symptoms and timing of sample collection.