Zika virus: What are the causes and symptoms, and where is it a risk?
Zika virus was declared a global medical emergency by the World Health Organisation (WHO) in 2016. While it may have fallen out of the headlines in recent months, and thankfully there have been no new wide-spread infections, the virus is still a danger.
Many people infected with Zika will have no symptoms, but the disease poses a serious risk to pregnant women. It’s connected to birth defects such as microcephaly, where babies are born with abnormally small heads and significantly hindered brain development. Here’s a brief rundown about what causes Zika, and what work is being done to prevent it spreading.
What is Zika?
Zika is a form of flavivirus spread by mosquitoes and which was first identified in Uganda in 1947 in monkeys. It was uncovered while researchers monitored the spread of yellow fever and was later identified in humans in 1952 in Uganda and the United Republic of Tanzania.
The earliest human infections were found across Africa and Asia but it spread more rapidly and more widely in 2007. In July 2015, Brazil reported a link between Zika and Guillain-Barré syndrome and three months later it was associated with microcephaly, referred to as a ‘brain-shrinking’ disease.
What are the symptoms of Zika virus?
Only one in five people with Zika will show symptoms. Those that do have symptoms will generally be mild, and last for a period between two and seven days. According to the NHS, these symptoms can include rash, itching, fever, headache, joint pain with possible swelling, muscle pain, conjunctivitis, lower back pain and pain behind the eyes.
How can you contract Zika virus?
Zika virus is mainly passed by Aedes mosquitoes, a genus found in tropical and subtropical zones. It’s the same kind of mosquito that transmits dengue, chikungunya and yellow fever. You can also contract Zika from sexual intercourse, which is a particular concern given the danger the virus poses to fetuses. There have also been cases of Zika transmitted through blood transfusions, although these are only a small number of cases.
Why is Zika virus dangerous for pregnant women?
The World Health Organisation says Zika virus infection during pregnancy “is a cause of congenital brain abnormalities”. These include microcephaly, which can mean babies are body with small heads and hindered brain development, and Guillain-Barré syndrome, which is a serious autoimmune disorder.
Where in the world am I at risk of contracting Zika virus?
The Centre for Disease Control (CDC) and Prevention has a handy map of travel information around Zika. In a nutshell, places where the virus is a risk are sub-tropical and tropical, with notable countries including Brazil, Mexico, Argentina, Ghana, Sudan, Pakistan, India and Indonesia. The CDC advises pregnant women not to travel to these countries, and couples travelling there should be aware of the risk to pregnancy.
What is being done to prevent the spread of Zika Virus?
Preventative measures to stop mosquito bites are one of the main ways to guard against Zika. Researchers are looking into a vaccine for pregnant women, with the Universities of Liverpool and Manchester, as well as Public Health England, working on £4.7m project to find a way to vaccinate against the disease. Public and global health minister Steve Brine told the BBC that the trial has “enormous potential to help millions of people”.