Factsheet about varicella
Varicella is caused by the varicella-zoster virus (VZV), which also causes shingles (herpes zoster). The virus typically affects children aged 2‒8 years.
Varicella may begin with cold-like symptoms, followed by a high temperature and a very itchy, blister-like rash. Clusters of spots appear over 3–5 days, mostly on the trunk of the body with some on the limbs. Symptoms vary in severity from person to person. It is possible to have varicella and have no symptoms.
You can only get shingles if you have previously had varicella and the virus is reactivated in your body. Shingles symptoms in older people usually start with a pain in the area of the nerve which is affected—often the chest. A rash of blisters then appears in the affected area, usually only on one side of the body. The rash usually lasts around seven days but the pain can last for longer. Someone with shingles can give the virus to someone who hasn’t had varicella and is not immune, but not the other way around: a child with varicella cannot cause shingles in another person.
Varicella is usually a mild disease; however complications can occur, most often in infants, adults, pregnant women and immunocompromised individuals. Complications can include infection of the skin, lungs (pneumonia) and brain (encephalitis). Varicella is a serious disease at any stage of pregnancy and the virus can cause miscarriage, congenital varicella syndrome, or neonatal varicella if the mother has the disease around the time of delivery (See section People most at risk for more information).
Ways to catch varicella
Varicella is highly infectious. About 96% of people who are exposed to the varicella virus, and are not immune by having had varicella before, will develop the disease. The virus is airborne and can be caught by breathing in air next to an infected person, by touching fluid from the blisters of someone with the rash, or on clothes, surfaces, toys or bedding. The virus can also be transmitted to the baby during pregnancy and birth if a pregnant woman gets varicella.
People most at risk
Varicella mostly affects young children, with around 90% of cases affecting children under the age of 15. It is usually a mild disease and most healthy children who get it recover quickly, although severe complications can occur in infants. Around 10% of varicella cases are in people over 15, and the effects of the virus are often more severe in adults. Pregnant women are most at risk from varicella, which can cause severe disease in the woman, increases the risk of miscarriage and can cause congenital varicella syndrome in the unborn baby or neonatal varicella in the newborn baby, both of which are rare but serious diseases.
Congenital varicella syndrome can leave the baby with severe, lifetime physical and learning disabilities. Untreated pneumonia caused by varicella in pregnant women can result in severe respiratory disease. Other people at risk of severe, life-threatening disease if untreated are those whose immune systems are deficient (the immunosuppressed) because of an inborn deficiency, an illness such as cancer or because of treatments, such as steroids or cancer therapy.
For a healthy person, there is no need for antiviral treatment for varicella. Fever symptoms can be reduced as in any illness and a cooling lotion can be used to stop the rash from itching. People who have shingles may be given antiviral drugs.
People at higher risk of developing complications (above 12 years of age, those with a weakened immune system or pregnant women) or anyone with complications should seek medical attention.
How to avoid getting varicella
All pregnant women and immunocompromised individuals should avoid contact with anyone who is suffering from varicella or shingles.
Patients that do not remember having had the disease, who are at high risk for severe varicella and complications and who have been exposed to varicella or herpes zoster may be offered varicella immunoglobulin, if available. The immunoglobulin should be given within 96 hours of contact. Consult a physician if you think you may belong to a risk group.
A vaccine is available which protects against the varicella virus; however policies on vaccine use vary across the EU. Varicella vaccination for all children is only recommended at national level in five countries (for the list of those countries see the ECDC vaccine scheduler). In most countries vaccination is available for adolescents without history of varicella and for the people who have higher risk of coming into contact with the varicella virus, like healthcare workers.
What to do if you have varicella
Infected adults should stay away from work and infected children should be kept away from school or nursery until all rash blisters have crusted and no new ones appear. This usually takes up to five days.