Onlinedesk | 31 May 2018 | 4:05 pm
Few days ago, I managed to catch chickenpox even though I had the vaccine about five years earlier. To make matters worse, I transmitted it to my husband, my sole caretaker in this city of Dhaka, who by the way, had the disease once before!
Well, my story ends here. But I believe it debunks two of the most popular beliefs regarding chickenpox or varicella
– 1. Vaccination gives immunity from chicken pox
– 2. Once contracted, one does not get it again.
Let’s try to dig a little deeper with the help of experts in order to reveal other lesser known facts about chickenpox, the tropical disease of the season!
When asked about how the disease came to be named like this, Dr Nazia Haque, assistant professor of Microbiology in Mymensingh Medical College Hospital(MMCH), lightly referred to a theory according to which, the boils on the skin of a person suffering from chickenpox resembles the peck marks caused by a chicken, so it is called chicken pox.
On the other hand, Professor of Virology at Bangabandhu Sheikh Mujib Medical University(BSMMU) Dr Saifullah Munshi provided another theory often given in medical texts for such type of nomenclature. According to this theory, the 5-10 mm wide red spots on the body caused by the disease were once thought to look like chickpeas.
Time, when it affects
In tropical countries between March and May, the weather remains moist, therefore, favourable for the varicella zoster virus (VZV) to spread, said Dr Saifullah.
“The changing season makes people prone to coughing and sneezing. VZV spreads through air when an infected person coughs or sneezes during the season changing time.” he explains.
Vaccine/ no vaccine
“Almost all (more than 99%) children develop immunity to the disease after two doses of vaccine, for older children and adults an average of 78% develop immunity after one dose and 99% develop immunity after the recommended two doses” explained the microbiologist, Dr Nazia.
Although some vaccinated children will still get chickenpox, generally they will have a much milder form of the disease with fewer blisters, lower fever and a rapid recovery compared to the unvaccinated person, she said recommending vaccination.
Once or twice
Most people gain immunity from chickenpox after contracting once. “Usually in 90% cases it gives lifelong immunity” Dr Nazia said.
The rest of the 10% get the chickenpox more than once due to weakened immune status, she adds.
Shingles/ Herpes Zoster
The initial infection with VZV is chickenpox. But the virus may remain inactive in nerve cells lifelong. Shingles, a skin rash with painful symptoms, may occur several decades later due to reactivation of the chickenpox virus from a latent state within a person’s body. The reactivation occurs due to decrease in level of immunity, changes in hormone, emotional status or exposure to ultra-violet ray, Virologist Dr Saifullah said.
Although this disease is caused by the same virus as chickenpox, the same vaccine usually does not give immunity from it.
“But if a person is given varicella vaccine at very early age (1-12yrs) he or she will not have chickenpox and there will be no latent state and ultimately no shingles.” Dr Nazia says.
In order to prevent Shingles, one needs to have Zoster Zortavax (Zoster vaccine) which contains 14 times more immunogen (a substance that evokes immune response) than the varicella vaccine also called varivax, she adds.
Chickenpox can be fatal. According to Dr Munshi, below the age of 14, the fatality rate is around one percent which increases to 10 % in 20 plus years’ population.
‘More blisters the better’
There is no base to this claim. It is not theoretically or clinically proven, both the doctors agree.
Use of neem/ Azadirachta indica
Taking bath in neem-boiled water to ease itching or recovering from chicken pox is a popular belief without scientific evidence, according to Dr Saifullah.
“Doctors now prescribe anti-viral medications, which is effective, tested and proven to stop the spread of the virus” said the virologist.
About Neem Dr Nazia said, although it has no effect on varicella, it has anticeptic and antibacterial effects. “It can prevent secondary bacterial cutaneous (relating to skin) infection” she explained.
No restriction on food
Dr Saifullah put no restriction on food for a chicken pox patient.
The patients should have plenty of water, fruits and the foods which boost immune system, said Dr Nazia.
Bathing, yes or no
Dr Saifullah said, “It is perfectly safe to bathe when you have chicken pox and you would probably feel much better having cleaned your skin.”
But he asked patients to remember that, while bathing one should avoid scrubbing the blisters which may transfer bacteria from nails into the pox lesion causing further inflammation which might leave a small permanent crater in the skin, Dr Munshi suggested.
It takes about two weeks (from 10 to 21 days) to develop chickenpox for an individual healthy person after exposure to an infected person with chickenpox or shingles.
An infected person can spread the disease from 1 to 2 days before they get the rash until all their chickenpox blisters have formed scabs (usually 5-7 days), Dr Saifullah tells.
Chickenpox spreads from person to person by direct contact or through the air by coughing or sneezing (respiratory route).
It is highly contagious which can also spread through direct contact with the fluid from a blister of a person infected or from direct contact with a sore from a person with shingles. It can also transmit by contaminated objects, airborne inhalation or through bites of bugs like mosquitoes, Dr Nazia said.
Chickenpox can be complicated in pregnant women.
“But these effects vary. It depends on the gestational (the period of time spent in the uterus between conception and birth) age of the pregnancy when the infection occurs,” Dr Saifullah said.
Congenital Varicella Syndrome may lead to abortion, still birth, Dr Nazia says.
Asked if chickenpox affects patients’ psychology, Dr Nazia said some psyhological effects may occur due to encephalitis, inflammation of the brain tissue caused by viral infections. It is an uncommon condition.
Dr Saifullah talked about the psychological effects which can occur after Shingles is healed.
“These patients suffer from anxiety and depression. It also affects the quality of life” Munshi adds.
Case studies in Bangladesh
Presently, there is no study published on incidence rate from Bangladesh, said Dr Saifullah. But according to a study published in 2002, the seroprevalence (the number of persons in a population who test positive for a specific disease) of varicella was 59 % among the Bangladeshi children aged up to 16 years. It means that by the time of reaching 16 years of age, 59 % children become infected by Varicella virus.
In the United States, in the early 1990s (before the vaccine was available), an average of 4 million people got varicella, 10,500 to 13,000 were hospitalised (range, 8,000 to 18,000), and 100 to 150 died each year.