Zika could have catastrophic effects

Soon after recovering from the shock of the deadly Ebola virus, the world is threatened with the onslaught of another virus, called Zika, which has a potential to quickly blow up into a pandemic. Within six months of its outbreak in Brazil, this vector-borne virus has already spread to 23 countries. The forthcoming Olympic games in Rio de Janeiro, Brazil, may further heighten the risk of its dispersal across the globe given about 500,000 people are expected to throng the venue of the games. The World Health Organization (WHO), which was criticised for its slow response to Ebola, has lost little time in taking note of the explosive spread of Zika and proclaiming it an "extraordinary event" to be treated as an "international emergency".

In India, the government has already issued advisories asking people to avoid travelling to countries, where Zika cases have been reported. International airports have been instructed to put up signs asking incoming passengers to report conditions like fever, body rash, joint pains and conjunctivitis - the usual symptoms of Zika infection - within two weeks of travel. Besides, the health ministry has set up a technical committee to keep close tabs on the global Zika scenario and evolve a plan of action to stem breeding of Aedes mosquitoes. The report of this panel and implementation of its recommendations must be swift. Zika is not as deadly as Ebola, but the consequences of its infection are no less disquieting, especially in the case of expectant mothers. It is linked to microcephaly - a condition in which babies are born with unusually small heads and damaged brains. Over 3,700 cases of this abnormality have already been reported from Brazil. If this virus comes to India, the count of babies with such defects would be mind-boggling.

The Zika virus is disseminated though the same species of day-biting mosquitoes - Aedes aegypti - which transmit dreaded diseases like dengue, chikungunya and Japanese encephalitis. The chances of its rapid spread in countries like India, where these maladies and their vectors already exist, are rather high. Controlling the mosquitoes is a must to prevent it. But this has been difficult in the past. Fighting Zika is tough also because those infected may not show any visible symptoms - but yet serve as potent disseminators of the virus through mosquitoes. Tracking the movement of the infection is, therefore extremely difficult. Worse still, there is no known cure or vaccine for it on the horizon.

Out-of-the-box strategies are, therefore, needed to keep this menace at bay. One possibility is to lift the ban on dichloro-diphenyl-trichloroethane or DDT, the most powerful and effective pesticide against mosquitoes. Another possibility is to use the recently evolved genetically modified mosquito that can inhibit the growth of its own species. It carries a lethal gene which causes its offspring to die before being able to bite human beings. Brazil is trying this out on a pilot basis, claiming 80 to 90 per cent success. However, there is no escape from redoubling efforts to develop drugs or vaccines to cure or prevent this infection.