What is the Zika virus

The Zika virus is spreading explosively through Latin America and beyond. What it is, where it comes from, how it proliferates and what is being done to fight it.

The Zika virus has gripped much of Brazil and Latin America. There have also been confirmed cases in the United States, Germany, Denmark, Great Britain and Italy. Most recently, it has concerned health officials due to its suspected link to a dangerous condition known as microcephaly, observed in over 4,000 children in Brazil reported since October 2015. With the 2016 Olympics in Rio de Janeiro only a matter of months away, the need to deal with the virus is urgent now more than ever, given the World Health Organisation (WHO)’s warnings that it is “spreading explosively“.


Where the Zika virus comes from

It is named after the Zika forest in Uganda, where it was discovered in monkeys in 1947. The first cases of the mosquito-borne disease date back to the 1950s: the first human case was registered in Nigeria in 1954. It is only in the past few years that the virus has spread rapidly “infecting probably a couple of million people” in Latin America and the Caribbean according to Professor Scott Weaver, Director of the Institute for Human Infections and Immunity in Texas, USA.         

Why it is feared

The suspected connection between the virus and microcephaly was first detected by Dr. Vanessa Van der Linden of Barao de Lucena Hospital in Recife, Brazil. The condition causes infants to be born with smaller than normal heads and a poor prognosis for brain function and life expectancy. There is no vaccine or treatment for the virus, whose symptoms include fever and joint-pain, though some of those infected suffer none at all.    



How it spreads

The virus has also raised alarms because of fears that, whilst it was initially confined to the Aedes aegypti mosquito, it has now spread to the more common Culex mosquito, therefore potentially widening its distribution. There are approximately 20 times more Culex mosquitoes than Aedes aegypti mosquitoes, and they are present in more countries. Furthermore, there are suspicions the virus can be transmitted via sexual intercourse.


Why it has spread

What, according to some, could become an “explosive pandemic” presents a perfect storm in Brazil in particular. Given the country’s tropical and subtropical climates, and that poverty and slum conditions are rife, these factors present fertile ground (such as stagnant water) for mosquitoes to breed. The female mosquito can lay up to 100 eggs a time, three times a week.  


What is being done to counter it

The advice from the governments of Brazil, El Salvador and Colombia has been blunt as they have told women not get pregnant, in the hope of reducing the likelihood of children being born with microcephaly. The WHO has urged that the potential breeding sites of mosquitoes are destroyed and normal protections to prevent mosquito bites are used to slow the spread of the virus. Meanwhile, Brazilian President Dilma Rousseff has called for a summit of the 33-member Community of Latin American and Caribbean States (CELAC) to launch “cooperative action in the fight against the Zika virus”. Within Brazil, the army has been called upon to help fight it and provide reassurance.



What is apparent in the growing epidemic is that health is a global public good and thus a concern for all of us. It seems safe to say that the virus would not spread as quickly if living standards were better in Brazil, as well as in other countries. In the same way it is commonly said that “when the United States catches a cold, the world gets the flu”, a saying alluding to the nation’s economic influence, we can say that “when Brazil gets a bite, the whole world gets the Zika virus”.


Featured image: Disinfesting against the Zika virus in Rio de Janeiro  © EPA
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