• The diagnosis is based on the clinical symptoms and confirmed by certain laboratory tests.
• In acute phase of illness there will be reduced WBC count with lymphocytes decreased and reduced neutrophils.
• Serological confirmation is done with the detection of IgM antibody in serum. IgM antibody appears after 10 days after the onset of rash and remains for a month.
• A four-fold rise in IgG antibody also occurs in acute phase taken 2-4 weeks later.
• Culture test- Also virus is isolated from blood, urine or respiratory secretions.