PCL2- Diagnosis of Shingle

Early diagnosis of shingles (within 3 days of the rash appearing) may help lessen the duration of the outbreak, as well as prevent complications of shingles, such as continuing pain after the lesions have healed.
Before the shingles rash appears, diagnosis of this condition may be difficult. Symptoms of shingles can mimic other conditions.

1. If the rash has appeared, identifying this disease only requires a visual examination.

2. Tsanck Smear
- is helpful for diagnosing acute infection with a herpes virus, but does not distinguish between HSV and VZV

Procedure
Gently rupture fresh vesicle with scalpel blade
Gently scrape mushy debris from vesicle base
Smear debris onto microscope slide

Examination
Examine under 10x power
Examine cells under 43x power

Positive Test: Tsanck cells (multinucleated giant cells) are found in Varicella and Herpes Zoster.


3. VZV-specific IgM antibody

-Most popular test detects VZV-specific IgM antibody in blood.
-Three enzyme-linked immunosorbent assay (ELISA) formats is used to detect VZV-specific IgM antibodies in human serum;

a. Varicella-zoster virus (VZV) indirect ELISA;
b. VZV IgM capture using biotin;
c. VZV IgM capture using peroxidise to detect.

Enzyme-Linked Immunosorbent Assays (ELISA) rely on the ability of biological materials(antigens) to adsorb to plastic surfaces such as polystyrene. Blue colour develops if a specific antigen is present.

Procedure of ELISA : https://elisatestkits.com/pdf/Varicella_IgG_1412Z.pdf

-Various methods of serodiagnositic tests for the detection of VZV antibodies in a patient's serum include indirect immunofluorescence, neutralization, complement fixation and fluorescent antibody to membrane antigen.

4. PCR Test of Lymph.
- Lymph collected from a blister is tested by the PCR for VZV DNA
- Rapid diagnosis of Varicella is polymerase chain reaction (PCR) out of specimen collected from lesions
-Primers selected from Varicella-zoster virus (VZV) gene 28 proved to be most sensitive.
-according to studies, resulted in 100% sensitivity and specificity.


5. Viral Culture
- Virus can be propagated in cell culture, but little or no virus is released into the culture media.
- Viral DNA and selected viral transcripts can be detected.