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Chickenpox

What is chickenpox?

Chickenpox is a highly contagious disease caused by the varicella virus, a member of the herpes virus family. It is the most commonly reported childhood disease. In 1994, there were 5,977 cases reported among New York City residents (rate of 81.6 cases per 100,000 persons). Effective in 1995, chickenpox is no longer required to be reported to the New York City Department of Health.

Who gets chickenpox?

Almost everyone gets chickenpox. In metropolitan communities, about 75percent of the population has had chickenpox by age 15 and at least 90 percent by young adulthood. In temperate climates, chickenpox occurs most frequently in the winter and early spring.

How is chickenpox spread?

Chickenpox is transmitted to others by direct person-to-person contact, by droplet or airborne spread of discharges from an infected person's nose and throat, or indirectly through articles freshly soiled by discharges from an infected person's lesions. The scabs themselves are not considered infectious.

What are the symptoms of chickenpox?

Initial symptoms include sudden onset of slight fever and feeling tired and weak. These are soon followed by an itchy blister-like rash. The blisters eventually dry, crust over, and form scabs. The blisters tend to be more common on covered than on exposed parts of the body. They may appear on the scalp, armpits, trunk, and even on the eyelids and in the month. Mild or inapparent infections occasionally occur in children. The disease is usually more serious in adults than in children.

How soon after infection do symptoms appear?

Symptoms commonly appear 13-17 days after infection, with a range of 11-21 days.

When and for how long is a person able to spread chickenpox?

A person is able to transmit chickenpox from five days before onset of rash to not more than six days after the appearance of the first lesion. Contagiousness may be prolonged in people with impaired immunity.

Does past infection with chickenpox make a person immune?

Chickenpox generally results in lifelong immunity. However, this infection may remain hidden and recur years later as Herpes Zoster (shingles) in older adults and sometimes in children.

What are the complications associated with chickenpox?

Reye's syndrome is a potentially serious complication associated withchickenpox. Newborn children (less than one month old) whose mothers are notimmune, and patients with leukemia may suffer severe, prolonged or fatalchickenpox. Immunodeficient patients and those on immunosuppressive drugs may have an increased risk of developing a severe form of shingles.

Is there a treatment for chickenpox?

In 1992, acyclovir was approved by the U.S. Food and Drug Administration for treatment of chickenpox in healthy children. However, because chickenpox tends to be mild in healthy children, most physicians do not feel that it is necessary to prescribe acyclovir.

Is there a vaccine for chickenpox?

A vaccine to protect children against chickenpox was first licensed in March 1995. It has been recommended for children aged 12 months or older. Older children and adults who have previously had chickenpox do not need to be vaccinated. Contact your doctor for further information about the chickenpox vaccine.

What can be done to prevent the spread of chickenpox?

The best method to prevent further spread of chickenpox is for people infected with the disease to remain home and avoid exposing others who are susceptible. If they develop symptoms, they should remain home until one week after the skin eruption began or until the lesions become dry. Persons with chickenpox should avoid unnecessary exposure of non-immune newborns and immunodeficient patients. If high-risk newborns and immunodeficient patients are exposed to chickenpox, a dose of varicella zoster immune globulin (VZIG) is effective in modifying or preventing the disease as long as it is given within 96 hours after exposure.

Chickenpox Fact Sheet