The Varicella zoster virus:

Chickenpox is an acute, highly infectious disease causes by infection with the varicella zoster virus (VZV).  Chickenpox is a mild and common childhood illness that is mostly seen in children under the age of 10. It is a highly contagious viral infection that spreads easily from person to person.  It causes a rash of red, itchy spots that turn into fluid-filled blisters.  They can crust over to form scabs, which eventually drop off.  Some children have only a few spots, but other children have spots that cover their entire body.

It is unusual for an adult to have chickenpox as the disease is more common in childhood. Because most people have had chickenpox by the time they are an adult, 90% of adults raised in the UK are immune.  However, if they haven’t had chickenpox as a child they may be higher risk of severe disease. 

Chickenpox can be a seasonal disease – there is often a peak between March and May although this has been less noticeable in recent years.