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HindustanTimes Sat,12 Jul 2014
Firewalling the viral overload in winter air
Sanchita Sharma, Hindustan Times
New Delhi, November 24, 2012
First Published: 22:52 IST(24/11/2012)
Last Updated: 22:54 IST(24/11/2012)

Which came first, the chicken or the egg?” This existential question has perplexed philosophers since time began, and annoyed the rest of us since school began.

And just when most of us dismissed metaphysical debate as a colossal waste of time — along with colonoscopy and the new Shah Rukh Khan-starrer Jab Tak Hai Jaan — British scientists came up with the definitive answer: The chicken came first.

Their keen scientific minds aided by a lot of research funds have identified a protein found only in a chicken’s ovaries that is vital for egg formation. The protein speeds up the development of the egg’s hard shell, which protects the chick growing inside. This means the egg can only exist if it is created inside a chicken. QED.

Which brings me to the other conundrum that has befuddled humans for generations: does winter air make viruses hyperactive, or does the cold weather make immunity sluggish, making us susceptible to infection?

Contradicting the belief that flu spreads because the cold makes the immune system weak, virologists have established that you cannot catch the flu from just sitting out in the cold. Flu viruses spread differently from cold viruses. While cold viruses spread mainly through direct contact, such as when a person touches a contaminated surface with residue of cold viruses, or when an infected person shakes hands. In contrast, flu viruses are transmitted through the air, in the form of aerosol droplets of coughs and sneezes.

Winter conditions make the flu virus more stable as cold, dry air pulls the moisture out of infected droplets released through coughs and sneezes. This allows the virus to linger in the air much longer, making it more likely that someone to breathe them in. When the air is more humid, these droplets pick up water, get bigger, and fall to the ground, where they can’t cause infection.

Winter air also dries out the nasal mucosa, which makes the nasal passage and airways crack and allows virus to enter the body more easily.

Add to this the winter cold leading to people spending more time indoors coughing and sneezing on each other and the chances of you getting infected rise rapidly, with flu season peaking from November through March. The proximity argument holds best among children, who have at least six to seven bouts of flu in a year, largely because they have suspect hygiene and share germs with each other generously.

More than the weather, what lowers immunity is the lack of sleep, an erratic diet, smoking and alcohol. Seasonal fluctuations also depend on vitamin deficiencies, such as reduced levels of sunlight — with heavy smog compounding shorter daylight hours — causing the body to produce less vitamin D, which increases susceptibility to the flu.

Flu symptoms are unpleasant — fever, cough, sneezing, headache, aching muscles and tiredness — but not life-threatening. However, flu weakens the immune system, making the body vulnerable to more serious infections, such as pneumonia. Because the flu is caused by a virus and not bacteria, antibiotics cannot be used to treat them. Like the common cold, flu can only be treated by bed rest, drinking fluids, and taking over-the-counter medicines to ease symptoms of fever and pain till the virus runs its course in five days to a week.

The best defence is avoiding direct contact with infected people, coughing or sneezing in a tissue or fabric instead of your hand, and washing hands frequently to avoid infection from contaminated surfaces, such as doorknobs and keyboards. People with compromised immunity — pregnant women, people recovering from a surgery or an illness, and people over 65 years — should consider getting vaccinated as they are the most vulnerable to flu complications, such as pneumonia.

That done, you are all set to embrace the cold without fear of the flu.


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