Topic: Chickenpox Varicella
Description
Chickenpox (also called varicella) is an acute infection caused by a virus, known as the varicella-zoster virus. For the majority of children chickenpox is a mild illness of short duration with complete recovery. It is more severe in adults and can cause serious and even fatal illness in immunosuppressed individuals of any age. If a woman develops chickenpox during pregnancy there is a very small but real chance of damage to her unborn baby. If she develops chickenpox late in pregnancy or very soon after birth the infection can be serious and even life threatening, for the newborn baby.
Symptoms
Chickenpox usually begins with a slight fever, headache, runny nose and cough. A day or two later a rash begins, starting as small pink blotches but rapidly progressing to blisters which usually last three to four days before drying out and turning into scabs.
The chickenpox virus is spread through coughs and sneezes and through direct contact with the fluid in the blisters of the rash. The dry scabs are not infectious. Since shingles blisters also contain the virus, a person who has never had chickenpox can become infected with chickenpox from someone who has shingles.
The usual time between contact with the virus and the development of the illness is about 14-16 days, although sometimes it can take longer.
An individual with chickenpox is infectious to about one to two days before the onset of the rash and until the blisters have all scabbed, usually four to five days.
Treatment
No specific treatment is recommended or required for otherwise healthy children with chickenpox. It is important to try to prevent a young child from scratching the rash as scratching can result in permanent scarring or secondary infection. Frequent baths, to which an anti-itch solution (eg. Pinetarsol) has been added, can reduce the itchiness.
Paracetamol can be used to lower temperature or to reduce discomfort. Aspirin must not be given to young children and adolescents due to the risk of developing a severe condition called Reyes Syndrome. This is particularly important for children who have or who may be developing chickenpox.
Control
People with chickenpox should be excluded from childcare facilities, schools or work for at least five days after the rash first appears or until dry scabs have replaced all blisters. Any contacts with lowered immunity, such as those with leukaemia, should be immediately excluded and referred for specialist advice. Good hygiene practices, such as washing hands after blowing or wiping nose, after coughing and before preparing food or eating should be maintained.
Varicella vaccine has been shown to be effective in preventing chicken pox if given within three days and possibly up to five days of contact with an infected person, with earlier administration being preferable.
An injection of zoster immune globulin (ZIG) given within 96 hours of exposure to chickenpox provides immediate but temporary protection against chickenpox and may be recommended if exposure has occurred for individuals at high risk of severe disease or pregnant women who are not immune to chickenpox. ZIG is not recommended for otherwise healthy children or adults.
Prevention
A safe and effective chickenpox (varicella) vaccine is now available in Australia.
As of 1st November 2005, a single dose of chickenpox (varicella) vaccine will be provided free of charge to-
- all children aged 18 months, and
- children aged 13 years who have no prior history of chickenpox or vaccination.
If there is uncertainty whether a person has had chickenpox, it is still quite safe to have the vaccine.
Chickenpox (varicella) vaccine is also recommended (but not funded) for-
- non-immune people in high-risk occupations such as health care professionals, teachers and staff in child-care services
- non-immune women prior to pregnancy
- non-immune parents of young children and
- non-immune household contacts, both adults and children, of people with lowered immunity.
Help and Assistance
For further information, please contact your local doctor, community health centre or nearest public health unit.
Other Resources
Australian Childhood Immunisation Register (ACIR)
A website about immunisation and the Australian Childhood Immunisation Register (ACIR), produced by the Health Insurance Commission.
Commonwealth Department of Health and Ageing
Publications, including the current editions of the Australian Immunisation Handbook.
Immunise Australia
A website on standard childhood immunisation produced by the Australian Department of Health and Ageing.
Department of Health and Ageing
Conditions and diseases section.
References and related content
Heymann, D., ed. 2004. Control of Communicable Diseases Manual, 18th edition. Washington, DC: American Public Health Association, pp 94-99.
National Health and Medical Research Council, 2003. The Australian Immunisation Handbook (8th Ed.) Canberra: National Capital Printing.
Last Updated: 11th July, 2011
Date Valid to: 31st December, 2010
