Chickenpox - Description

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Photo by: Dan Race

Chickenpox is caused by the varicella-zoster virus (a herpes virus; see herpes infections entry) and affects about four million Americans each year. Of this number, five thousand to nine thousand require hospitalization. About one hundred people die of the disease each year.

A person becomes infectious (able to pass on the virus) a day or two before a rash first appears. He or she remains infectious until the blisters have formed scabs. Scabs form four to seven days after the rash first appears. During this period, a child with chickenpox is expected to stay home from school so that he or she will not pass the disease to other children.

Chickenpox has always been a common disease among children in the industrialized world. The disease can occur at any age. However, about 80 to 90 percent of all American children under the age of ten have already been infected. Because a single attack of the virus provides immunity, chickenpox occurs in only 5 percent of adults in the United States. If an adult contracts chickenpox he or she is more likely to experience complications than children; more than half of all deaths from chickenpox occur among adults.