To many people around the world, it must seem as though the Zika virus has suddenly appeared from nowhere. The intensity of coverage and health warnings have gone from naught to 60 in the space of a year, and many members of the public have been left wondering: why now?
The Zika virus was first identified in 1947 in the Zika forest of Uganda. The virus mainly affected areas in Africa and South East Asia, and due to its fever symptoms being relatively mild and the outbreaks being small not much attention was paid to it. This meant that possible links to serious developmental conditions such microcephaly were not realised.
The Zika virus has been infecting many people in Brazil and spreading across Latin America for the past year now, and with almost 30 countries affected and infection numbers still rising, it is now the biggest Zika outbreak on record. But how did the Zika virus get there, and why is it causing an epidemic like never before?
It’s possible that a tourist could have taken the virus to Brazil during the 2014 FIFA World Cup, but no one knows for sure. However, the reasons for its rapid spread are much easier to pin down; the main carrier of the Zika virus, the Aedes aegypti mosquito, is found across most of Brazil and numbers have been increasing over the past few years. The warm climate, poor water drainage facilities, and lack of simple features such as air conditioning and screen windows to prevent insect entry into homes all allow for the perfect breeding ground for these insects. Many scientists agree that climate change could be a factor in the spread of Zika, as mosquitos prefer warmer climates to survive and breed in. With 2015 being the hottest year on record so far, and temperatures in Brazil increasing by up to 3 °C, this definitely seems likely. Additionally, as Zika virus is new to Latin America, the populations will have acquired no immune defences against it, making them much more susceptible to infection.
So what’s next for the Zika virus? If temperatures around the world continue to rise, then it is certainly likely that the aegypti mosquito populations will also increase and spread to new areas as they become warm enough to sustain them, with international travel only making this threat more serious. The World Health Organisation (WHO) is expecting the Zika virus to spread across the rest of the Americas, avoiding only Canada and Chile whose climates are too cold for Aedes aegypti to survive. Though it’s predicted the mosquitos will hit the USA over the summer, it will mainly be the warmer southern states that are affected.
As more complications in pregnancy and foetal development are linked to the Zika virus, more women are being warned against becoming pregnant. This could cause problems for people in areas with poor access to basic contraception, as well as women who may wish to terminate their pregnancies but are living in places where abortion is illegal or strictly controlled. Due to breakouts of Zika never happening on this scale before, effects on foetal development in pregnancies were unknown until recently. Although we now know of the links between Zika and microcephaly, it’s possible that more health complications surrounding this disease may become apparent as the epidemic escalates.
Fortunately for us in the UK, our climate is cold enough to make it unlikely for the Aedes aegypti mosquitos to survive and thrive here, though infection through sexual transmission is still a possibility. Though most of Europe is too cold for aegypti to survive and breed in, there are other mosquito species such as Aedes albopictus that can survive in some European countries and have been known to spread Zika
Though the risk for Zika spreading across Europe is said to be low to moderate, this epidemic is still a world problem that we need to contribute to fighting. We can help by being cautious when travelling to affected areas, and using insect repellent and contraception where necessary. Though many people have already been affected by Zika and its side effects, increasing education and worldwide efforts to treat and prevent the disease will hopefully help combat the Zika virus epidemic.