{"id":7162,"date":"2014-06-06T11:41:21","date_gmt":"2014-06-06T01:41:21","guid":{"rendered":"http:\/\/www.mvec.vic.edu.au\/?page_id=69"},"modified":"2025-07-15T14:22:52","modified_gmt":"2025-07-15T04:22:52","slug":"%e0%a4%9b%e0%a5%8b%e0%a4%9f%e0%a5%80-%e0%a4%9a%e0%a5%87%e0%a4%9a%e0%a4%95","status":"publish","type":"references","link":"https:\/\/mvec.mcri.edu.au\/hi\/references\/varicella\/","title":{"rendered":"\u091b\u094b\u091f\u0940 \u091a\u0947\u091a\u0915"},"content":{"rendered":"
<\/p>\n

What is it?<\/h2>\n

Varicella (chickenpox) is a highly contagious<\/span> disease caused by <\/span>infection <\/span>with <\/span>the varicella-zoster virus (VZV)<\/span>.<\/span> After a person recovers<\/span>,<\/span> the virus stays dormant (inactive) within the dorsal root ganglia of the spinal nerves and can later be reactivated, presenting as <\/span>herpes zoster (shingles)<\/span><\/a>.<\/span><\/span>\u00a0<\/span><\/p>\n

What to look for<\/h2>\n

Symptoms begin 7 to 21 days after exposure to the virus. Fever, rhinorrhoea (runny nose) and lethargy lasting 1 to 2 days are the first signs of disease (prodromal period). This is followed by the appearance of a pruritic (itchy) rash which is initially maculopapular (flat discoloured areas and raised areas) then becomes vesicular (fluid-filled blisters). The vesicles rupture then crust over, usually within 10 to 14 days. The rash can cover any part of the body including inside the mouth, on the scalp, eyelids and genital area. Unvaccinated children may experience 200 to 500 lesions. Approximately 5% of cases will be subclinical (symptoms are so mild they remain undetected under clinical examination). <\/span>\u00a0<\/span><\/p>\n

Most cases of varicella are self-limiting (will resolve by itself), but complications can include secondary bacterial infections, septicaemia (blood infections), pneumonia, meningitis, encephalitis and acute cerebellar ataxia (uncoordinated muscle movements).<\/span>\u00a0<\/span><\/p>\n

Varicella infections during pregnancy can result in congenital varicella syndrome in the child. Symptoms of congenital varicella syndrome include skin scarring, eye anomalies, limb defects and neurological malformations. The risk of congenital varicella syndrome is higher when infection occurs in the second trimester. Infants who have been exposed to varicella through a maternal varicella infection can develop herpes zoster, but this is rare.<\/span>\u00a0<\/span><\/p>\n

Despite vaccination, some people may still develop disease if exposed to infection. This is known as breakthrough disease. Breakthrough varicella symptoms are usually mild. Patients are typically afebrile and develop fewer skin lesions. People experiencing breakthrough disease are contagious and can transmit disease to others.<\/span>\u00a0<\/span><\/p>\n

How is it transmitted?<\/h2>\n

Varicella is transmitted by inhaling respiratory droplets that are made airborne when an infected person coughs or sneezes. It can also be spread by direct contact with the fluid inside the vesicles or through contact with items that have been contaminated with vesicle fluid.<\/span>\u00a0<\/span><\/p>\n

A person with varicella is considered infectious for 1 to 2 days prior to the onset of the rash until all the lesions have crusted.<\/span>\u00a0<\/span><\/p>\n

Epidemiology<\/h2>\n

Varicella is highly infectious. More than 80% of non-immune household contacts of an infected individual will develop disease.\u00a0<\/span>\u00a0<\/span><\/p>\n

Prior to the introduction of vaccination in Australia in 2005, there were 240,000 cases of varicella annually, resulting in 1<\/span>,<\/span>500 hospitalisations and an average of 7 to 8 deaths. The rate of hospitalisation for varicella infection was reduced to 2.1 per 100,000 people in 2013. Most of these children were aged under 18 months, the scheduled age for varicella vaccination. (NB: Children can be safely vaccinated from 9 months of age.)<\/span>\u00a0<\/span><\/p>\n

Infants less than 4 weeks of age, <\/span>premature neonates, unimmunised adolescents, <\/span>pregnant <\/span>women<\/span> and immunosuppressed individuals are at<\/span> the<\/span> greatest <\/span>risk of severe disease and complications if they become infected.<\/span>\u00a0<\/span><\/p>\n

Prevention<\/h2>\n

Vaccines can<\/span> provide<\/span> protection against varicella infection.\u00a0<\/span><\/span><\/p>\n<\/div>\n\t

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