Chicken pox is caused by the varicella-zoster virus.
It belongs to the family of herpes viruses. Humans are the only carriers of this virus. The virus is present in the body fluids and in the lesions of skin and mucosa. Mode of transmission
Airborne droplets that are sprayed when the affected person coughs or sneezes
Direct contact with discharge from the blisters of the skin
Coming in contact with herpes or shingles infection
Once the virus enters the body it rests and reproduces in the lymph nodes of the body for about 3 to 4 days before it travels to the blood to infect the spleen and liver. It finally rests in the nerve roots near the spinal cord till it is activated. No trigger maybe needed for its activation, but sometimes it waits for events like stress or diminished immunity before it attacks.