What Causes Chickenpox?
Chickenpox is an infectious disease caused by the varicella zoster virus (VZV), a virus that is part of the herpes virus family. The same virus that causes chickenpox also causes herpes zoster (shingles) in adults.
Before the introduction of the varicella vaccine in 1995, approximately 4 million cases of chickenpox were reported annually, including 4,000 to 9,000 hospitalizations and 100 deaths. Since the introduction of the chickenpox vaccine, the number of cases of the disease has dropped dramatically.
(Click Chickenpox to learn more about the causes, symptoms, and treatment of this illness.)