Chickenpox is a disease that is generally benign, very contagious and very common. It is caused by the varicella-zoster virus (VZV).
After an incubation period of 10 to 21 days, the infection causes fever accompanied by the rapid appearance of a rash all over the body, leading to itching. Chickenpox lasts 1 to 2 weeks.
In most European countries that have not introduced widespread vaccination, 90% of the population under 15 years of age has already contracted chickenpox. In Belgium, it is estimated that 80 per cent of children aged 5 and over 90 per cent of children aged 10 have already had chickenpox.
After contracting chickenpox, the varicella zoster virus remains latent in the sensitive neural ganglia. However, the virus can reactivate, causing painful rashes in one to two limited areas of the body. This is what is known as shingles. Shingles usually lasts less than 2 weeks, although residual pain may persist after the rash. If the pain persists more than 3 months after the rash, this is called post-herpetic neuralgia, which can last from several months to several years.
Chickenpox is transmitted through the air (microdroplets of saliva) and by direct contact with the fluid in the vesicles. Chickenpox can also be transmitted by contact with the fluid in the vesicles of a person with shingles.
The diagnosis of chickenpox and shingles is essentially made on the basis of clinical presentation (characteristic rash). It is sometimes necessary to carry out a lab test (PCR), in particular to detect the virus in the event of certain complications such as neurological damage. Most of the time, no treatment is needed for chickenpox or shingles. For certain risk groups or complications, antiviral treatment may be necessary.
in Belgium, vaccination against chickenpox is indicated only for certain risk groups (see recommendations of the Superior Health Council). Full vaccination consists of two doses of a live attenuated vaccine that provides effective protection.
There are 2 vaccines against shingles:
Chickenpox is usually benign. However , serious forms do exist among the following groups at risk:
- non-immunized adults
- immunocompromised persons
- non-immunized pregnant women
- and newborn babies.
It is also possible, but rare, to suffer a complication after contracting chickenpox while being in perfect health.
The main complications of chickenpox are bacterial superinfection, especially cutaneous, pneumonia, neurological damage (encephalitis, cerebellitis, etc.), hepatitis, etc.
Increasing age and weakened immune function are risk factors for shingles complications. However, some complications, such as post-herpetic neuralgia, may also occur in the absence of these predisposing factors.
Other, much rarer complications are possible such as encephalitis, bacterial superinfection of the skin, impairment of sight or hearing, etc.