Chickenpox incubation period
Chickenpox (varicella) is a common, highly contagious, viral infectious disease of childhood. Usually mild, it’s characterised by a very itchy rash that can spread over the whole body. In the UK, it is common and most cases occur during winter and spring. Around 90% of the UK population has had chickenpox by the age of 15. It is not common in people from tropical and subtropical zones.
Transmission and incubation period
The varicella-zoster virus is transmitted through direct contact with the chickenpox blisters, by airborne droplets when coughing or sneezing, or through contact with infected items of clothing or bedding. Your risk of catching the virus increases if you have been in the same room as a person with chickenpox for 15 minutes or you were in close contact, for example, face to face, with an infected person.
The incubation period is seven to 21 (usually 10 to 21) days after exposure to the herpes varicella-zoster virus to the development of the symptoms. The disease is most contagious a day or two before the rash appears and until the rash is completely dry and scabbed over, about five to six days after onset of the rash.
Who is at risk of chickenpox?
- Anyone who has not had chickenpox
- Anyone who is not vaccinated against varicella-zoster virus
- Young children (under 10 years)
Who is at risk of complications?
- Newborns and very young babies
- Adolescents and adults tend to have severe forms and complications
- Pregnant women who have not had chickenpox are at risk of complications. They can develop severe forms of chickenpox, including varicella pneumonia.
- The virus can also cause congenital varicella syndrome in the unborn baby.
Most people gain life-long immunity after having chickenpox. The varicella-zoster virus becomes dormant in the nervous system and then it may become reactivated as herpes zoster or shingles in later life.
You can catch chickenpox from a person with shingles through direct contact with the blisters but you cannot catch shingles (herpes zoster) from someone with chickenpox or with shingles.