Disease
Fact Sheet Series:
What is chickenpox?
Chickenpox is a highly communicable disease caused by
the Varicella virus, a member of the herpes virus family.
Who gets chickenpox?
Almost everyone gets chickenpox. In metropolitan
communities, about 75 percent 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 winter and early spring.
How is chickenpox spread?
Chickenpox is highly contagious. 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 the 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. An itchy blister-like rash soon follows. The
blisters (vesicles) 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 mouth. Mild or unapparent infections occasionally occur
in children. The disease is usually more serious in adults than in
children.
How soon do symptoms appear?
Symptoms commonly appear 13-17 days after exposure with
a range of 11-21 days after exposure.
When and for how long is a person able to spread
chickenpox?
A person is usually able to transmit chickenpox from 1
to 2 days before the onset of the rash to six days after the appearance of
the first lesion. Contagiousness may be prolonged in people with altered
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 a proportion of older adults and sometimes in
children.
What are the complications associated with chickenpox?
Reye syndrome has been a potentially serious
complication associated with clinical chickenpox. For this reason,
children with chicken pox should not be treated with aspirin, which may
increase the risk of Reye syndrome. Newborn children (less than one month
old) whose mothers are not immune and patients with leukemia may suffer
severe, prolonged or fatal chickenpox.
Is there a vaccine for chickenpox?
Yes, a chickenpox vaccine was licensed in the U.S. in
1995 and is recommended for children 12 to 18 months of age and older
children who have not had chickenpox. Recipients of the vaccine should not
receive aspirin for 6 weeks after the vaccination.
To protect high-risk newborns and persons with weakened
immune systems following exposure, a shot of varicella zoster immune
globulin (VZIG) is effective in modifying or preventing disease if given
within 96 hours after exposure to a case of chickenpox.
What can a person or community do 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.
Avoiding
exposure of non-immune newborns and patients with weakened immune systems
to chickenpox is important.
For more information, contact your
Local
Public Health Department
Back to Communicable Disease
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Last Revised: November 04, 2008
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