What is Zika?
The Zika virus is a mosquito-borne infection which was first identified in Africa in 1947. It has spread significantly across the world since the first reported case in Brazil in 2015.
For most people it is a very mild infection and isn't harmful. However, scientists believe it's behind an unprecedented rise in the number of children being born with unusually small heads - microcephaly - in Zika infected areas.
The virus is transmitted to people primarily through an infected Aedes species mosquito, although it can also be passed from person-to-person via sexual contact with an infected man.Samples of Aedes aegypti mosquitoes, responsible for transmitting dengue and Zika. Credit: AP
What happens if I catch it?
The majority of those infected with Zika have no symptoms and won't even know they've got the virus. In others it can cause a mild illness with symptoms including a rash, conjunctivitis, fever and headaches. These will generally last for a few days to a week.
However, the virus can cause microcephaly and other congenital abnormalities in babies born to mothers infected with the virus.
The World Health Organisation (WHO) has said there is strong scientific consensus that Zika can also cause Guillain-Barre, a rare neurological syndrome that causes temporary paralysis in adults.
People very rarely die from Zika and infected people who have died have had underlying conditions.Baby Lara who was born with microcephaly in Brazil. Credit: Felipe Dana/AP
Is there a cure?
No vaccine currently exists to prevent Zika. However, in June 2016 researchers at the Pasteur Institute in France found that both Zika and dengue fever can be neutralised by the same antibodies, leading to the possibility of a super-vaccine to tackle both. The dengue virus is similar to the Zika virus. They both belong to the same viral family, called the Flaviviridae, and are transmitted by the same mosquito.
In January 2018 the WHO granted fast-track status to a Zika vaccine, bringing us a step closer to approving one.
People diagnosed with the Zika virus should get plenty of rest, drink enough fluids, and treat pain and fever with common medicines, according to the WHO.A transmission electron micrograph (TEM) of the Zika virus. Credit: CDC/PA
How do people catch it?
The main form of transmission is mosquito bites, however there have been some cases which have occurred through sex with an infected man. There is also evidence of transmission from mother to child during pregnancy.
What can I do to avoid it?
Prevention is key.
- Pregnant women should not to travel to areas where Zika is circulating
- Pregnant women's partners returning from Zika-infected should practice safer sex or abstain from sex throughout the pregnancy
- Avoid getting mosquito bites by using insect repellants, and wearing long-sleeved shirts and trousers
- Use air conditioning and/or a window screen to keep mosquitoes outside
- Sleep under a mosquito net
- Reduce the number of mosquitoes by emptying standing water from containers such as flowerpots or bucket
Where did Zika come from?
The Zika virus was first identified in Rhesus monkeys in 1947 and is named after the Zika Forest in Uganda. The first human case was detected in 1952 and since then there have been outbreaks in tropical Africa, Southeast Asia, and the Pacific Islands.
Prior to 2007, only a handful of cases had been documented. However, the symptoms are similar to many other diseases so the full extent of infection has probably not been fully recognised.
In May 2015 Brazil confirmed its first case of infection, which has since found its way into 65 other countries in the Americas.
The WHO declared Zika a Public Health Emergency of International Concern (PHEIC) in February 2016, declassifying it as an emergency in November 2016 and labelling it as 'long-term commitment'.
Where has the virus spread to?
As of July 6 2016, 65 countries and territories reported evidence of mosquito-borne Zika transmission since 2007. All but four of these have seen Zika emerge since 2015.
As of February 2018, there are twelve countries with a 'high risk' of Zika infection. These include
- Costa Rica
- Puerto Rico
- Sint Eustatius
Will it spread to the UK?
The mosquito that transmits Zika is not found in the UK.
However, as of February 1 2018, a total of 305 cases had been diagnosed in UK travellers since 2015, according to Public Health England. The majority of Zika cases in the UK wer related to travel to the Caribbean and South and Central America; seven of the cases diagnosed since 2015 have been pregnant women.
In December 2016, a woman in the UK was infected with the virus through sexual transmission.
In 2017, 18 cases were diagnosed; all were associated with travel to countries where Zika-carrying mosquitoes are found.
How did the virus affect the 2016 Olympics?
While a few athletes withdrew from the Games because of Zika, the Olympics were not under threat.
The WHO advised that cancelling or changing the location of the 2016 Olympic games would not significantly alter the spread of Zika. It maintained that the best way to reduce the risk of disease is to follow public health travel advice.
The Games took place during Brazil's winter, when there were fewer active mosquitoes and the risk of being bitten was lower.Health workers in Rio get ready to spray insecticide to combat the Aedes aegypti mosquitoes that transmit the Zika virus Credit: AP
- NATHNAC: travelhealthpro.org.uk
- CDC: cdc.gov/zika/index.html
- ECDC: ecdc.europa.eu/en/healthtopics/zika
- WHO: who.int/mediacentre/factsheets/zika/en/
- Foreign Office: gov.uk/guidance/zika-virus