Chicken Pox Causes

Chicken pox is caused by the Varicella zoster virus (VZV), which belongs to the herpes group of viruses. Being extremely contagious, exposure to the virus will result in chickenpox in more than 90% of unprotected individuals within a period of 10–21 days.

The virus spreads by both direct contact with fluid from broken chickenpox blisters and through respiratory droplets (dispersed into the air by coughing and sneezing). Chickenpox is most infective from 2 to 3 days before the rash appears until all the blisters have crusted over.

After infection, the virus remains dormant in the body throughout a person’s life. Although people cannot get chickenpox twice, the same virus may cause shingles, a viral infection of nerve roots. Rarely, contact with a patient who has shingles can result in chickenpox in a previously unexposed individual.