A primer on preventing Zika virus

The western hemisphere has been panicking over the spread of the Zika virus. In Brazil, local health authorities observed an increase in Zika virus infections and have declared an emergency.

While Brazil remains the worst-hit, with several infected, pregnant women giving birth to babies with microcephaly, the virus has also spread to other parts of South America and the Caribbean. And last week, China reported its first Zika case, but the patient was discharged after being declared Zika-free.

So far, India hasn't recorded any Zika case, but our country's climate is conducive for the virus to thrive – which is why a primer is a must.

Where does the Zika virus thrive?
As per the World Health Organisation, the virus occurs in tropical areas with large mosquito populations.

How do people get infected?
The virus spreads when one is bitten by an infected Aedes mosquito – the same species that spreads dengue, chikungunya and yellow fever. Given the incidences of the first two in India, particularly during the monsoon, people should take extra caution.

Is this virus contagious?
Currently, there is no evidence that indicates so. However, some reports indicate the virus has been isolated in human blood and semen. Experts are determining if it can be sexually transmitted or passed through blood transfusions.

What are the symptoms?
Initial symptoms include a light fever and rash. According to WHO, other symptoms may include conjunctivitis, muscle and joint pain. Those infected may also feel tired. No fatalities have been registered to date.

Why should pregnant women worry?
Authorities are investigating a possible link between the virus in pregnant women and microcephaly (a misshaped head due to poor brain development) in their babies. While there has been a lot of research corroborating this claim, there is no concrete evidence linking the two. Dr Ashwin Balagopal, an infectious disease expert at US-based Johns Hopkins, says that while there is no final confirmation to co-relate the virus with microcephaly, researchers are close to publishing a paper establishing a connection. "Last year, a pregnant European woman went to Brazil and contracted the disease. When she went back, she learnt that her unborn child had developed microcephaly," he says.

How is Zika virus disease treated?
Symptoms can be treated with common pain and fever medicines, rest and plenty of water. If the condition worsens, people should seek medical advice. There is currently no cure or vaccine for the disease itself.
Dr Ashwin adds that rare cases have seen a 20-fold increased risk of Guillain-Barré syndrome. "This is an autoimmune disease often triggered by infections in which the immune system attacks the myelin lining of nerve cells, resulting in weakness and paralysis. Two-thirds of affected patients lose the ability to walk, and 25 percent need to be put on a mechanical ventilator due to weakness of the respiratory muscles," he adds.

Is there a vaccine for the Zika virus?
Hyderabad-based Bharat Biotech recently said it was working on two possible vaccines. A company spokesperson said they had been developing the vaccine while also working on vaccines for chikungunya and dengue.
One vaccine is a 'recombinant' (created by genetic engineering), while the other is 'inactivated' (created by killing a pathogen or disease-causing virus in a way that it can't replicate, but can be recognised by the immune system). The vaccines will enter pre-clinical trials in two weeks, Bharat Biotech MD Krishna Ella told Reuters.

What experts are saying
"It is premature to comment on the vaccine candidates, but ICMR has put together a group of experts to examine their validity," says Dr Soumya Swaminathan, Director General, Indian Council of Medical Research (ICMR).

(With inputs from Reuters)

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When travelling to countries where the Zika virus is thriving:
Wear long-sleeved shirts and full-length pantsStay in places with air conditioning or use window and door screens to keep mosquitoes at bayUse a mosquito net if youare overseas or outside and are not able to protect yourself from mosquito bitesSource: Centre for Disease Controland Prevention

Home remedies for prevention:
Turn over empty pails and buckets so that they do not collect excess water. If the water cannot be emptied, cover the container/s when not in use.Clean out empty flower pots, and do not over water potted plants, as stagnant water is a breeding ground for mosquitoes.Apply mosquito repellent on exposed areas, during the day as well as at night on a regular basisMake sure your window and doorscreens do not have any holes. If so, block those areas properly toeliminate mosquitoes.