It is a viral disease caused by first exposure to the varicellazoster virus(VZV). The disease is identified with fever and can later get reactivated and cause shingles(herpes zoster).

Common symptoms are fever, chills, nausea and vomiting. The most obvious and the most well-known is the blistered and highly itchy rash. Most children have 200-300 lesions, which later form a crust or scab.

Yes, it is. Chickenpox is most contagious a couple of days before the rash appears and scabs have formed on all the lesions, i.e., till they dry up, which usually occurs in a week’s time after the onset of the rash.

The virus commonly spreads from person-to-person by air-borne droplets. This occurs when an infected person coughs or sneezes and releases secretions in the surrounding air. It can also spread by direct contact with chickenpox or herpes, since the wet lesions contain infectious fluid. In a few cases, it can also occur from an infected pregnant mother to her unborn or newly born child.

Chickenpox can occur both children and adults, males and females. Most people contract chickenpox sometime or the other during childhood or adolescence, but adults who have not been infected before are susceptible to infection and can develop chickenpox in adulthood if and when they come in contact with a case. As chickenpox usually affects young children, those who spend a lot of time with children, like teachers and persons running day-care centres have more chances of contracting the infection. In addition, healthcare providers (doctors, nurses and hospital personnel) are at added risk of developing the infection since they may come in contact with a case during the course of their duty. Chickenpox is usually more sever in older individuals who missed getting it when they were children.

Although for many children chickenpox does not produce major health problems, complications can develop in some cases. Secondary bacterial infection affecting the skin lesions is the most common complication that one encounters, especially when hygiene is poor and when bathing is not regular. Rarely, in a few children, the virus could prove more aggressive and cause infection in lungs leading to pneumonia and may affect the brain leading to swelling and infection (encephalitis). These could prove fatal. Other complications have been described, but these usually have a self-limited course. Rarely, residual scarring may be unsightly, leading to cosmetic concerns later in life.

Chickenpox is more severe in adolescents and adults than in children. The fever is higher and continues for a longer time. The rash is usually heavier with deeper and more lesions. The likelihood of complications is greater too. Adults are more likely to suffer from pneumonia. The chances of complications and risk to life tend to be higher when chickenpox is contracted later in life.

The interaction between chickenpox and pregnancy would depend on the timing of contracting the infection during pregnancy. If chickenpox is contracted by the pregnant lady during the first three months of pregnancy, there is a risk of congenital foetal malformations , or chances of abortion. Infection later in pregnancy but not too close to delivery allows maternal antibodies to be passed on to the foetus thus offering protection. Maternal chickenpox within 5 days prior to delivery or 2 days after is dangerous as this can result in transmission of the virus without antibodies to the child. Such chickenpox in the newborn can be life threatening as the baby’s immune response is poorly developed at this time.

Both these conditions are caused by the same virus i.e., varicella-zoster. First exposure to the varicella-zoster virus results in chickenpox; that is followed by immunity against the infection, which usually lasts a lifetime. The virus, however, hides in certain nerve roots and remains dormant. The virus may get reactivated many years later, leading to shingles (herpes zoster). Shingles usually afflict adults, especially old people, as the efficiency of the immune system declines age.

The full impact of chickenpox on patients and their families is often not appreciated. Physically, chickenpox is very uncomfortable for patients because they have to endure discomfort from symptoms such as rash and the associated itching, fever chills, nausea and vomiting. Patients often need to be isolated and kept at home. Thus, a schoolgoing child may miss school for a few days to as long as a month. Where both parents are working, it might require one of them to keep the child company and miss work. In adolescents and adults, chickenpox can be more serious and severe leading sometimes to complications. In some cases there could be residual scarring. Chickenpox infection can thus lead to loss of man hours in the form of missing school, college or working time.

Isolating infected individuals by them keeping away from school or work will help reduce transmission of the virus. Vaccination is effective way of preventing suffering from chickenpox.

Where chickenpox is more prevalent among older age group – in whom complications are more likely – it represents a major health threat. It follows that some means of controlling the situation is vital, and pro-active measures like vaccination in children would be most effective. Vaccination of children are susceptible adults and adolescents can reduce the disease burden and transmission of chickenpox. This would also result in avoiding the social impact of the disease and reducing healthcare costs.

Vaccination can be offered to individuals more than one year of age, who have no suffered previously from chickenpox.

Clinical studies of currently available varicella vaccines show they are close to 100% effective and well-tolerated. However, long-term follow –up of vaccines has shown the incidence of a mild breakthrough-like syndrome in 1-4% of vaccine recipients.