Zika Virus

The Zika virus is spread by the yellow fever or dengue mosquito (aedes aegypti). Although the disease (Zika fever) is usually fairly mild, there are increasingly more indications that an infection during pregnancy can harm the unborn child.

In May 2015 the first patients with Zika were diagnosed in Brazil. This outbreak has spread across various countries in South and Central America. In November 2015 doctors saw the first indications that an infection with the Zika virus during pregnancy could possibly harm the unborn child. Research into this is currently being carried out and is being coordinated by the WHO

In The Netherlands infection with the Zika virus has been found only in people who have contracted the virus abroad. To date over seventy people have been diagnosed with the infection but there are probably a lot more people who have been infected, as only one in five people actually have symptoms after being infected. It is unlikely that the Zika virus will spread within The Netherlands as the mosquitoes responsible for transmission do not occur in The Netherlands.

Advice for pregnant people and their partners

  • Pregnant women and women who want to become pregnant during or immediately after their journey are advised to postpone non-essential journeys to a country where the Zika virus is prevalent. They should discuss the need for the journey and possible preventive measures with their GP. 
  • Pregnant women should report any recent visit to countries where the Zika virus is prevalent during their regular check-ups with their obstetrician or GP, especially if they have any symptoms within two weeks of their return that are in keeping with an infection by the Zika virus. 
  • Men who have been in countries where the Zika virus is prevalent and whose wife is pregnant are advised as a precaution to use a condom in the case of sexual contact for up to two month after their return. 
  • People who want to become pregnant are advised to postpone this until at least a month after their return from a country where the Zika virus is prevalent. During this time they should use a condom in the case of sexual contact.

Symptoms

Symptoms of Zika fever occur usually 3 - 12 days after a bite from an infected mosquito. People who are infected with the Zika virus do not always get any symptoms. Around one in five people have symptoms. Most people recover within a week without any serious problems. 

Possible symptoms of Zika fever are:

  • acute, but usually not high, fever
  • non-suppurative eye infection 
  • muscle and joint pain (in particular in hands and feet, sometimes with joint swelling)
  • skin rash (often starting on the face and spreading over the rest of the body)
  • and less often: headache, lack of appetite, vomiting, diarrhoea and abdominal pain.

Complications 

Possible complications from Zika fever are rare. During outbreaks the following complications were described: 

  • Guillain-Barré syndrome. It is still unknown how often this occurs but it is probably relatively rare.
  • There are increasingly more indications of a link between infection with the Zika virus during pregnancy and a brain malformation in the unborn child. Research is currently being carried out to ascertain whether this brain malformation is actually caused by an infection with the Zika virus during pregnancy. 

Infection and prevention

The Zika virus is transmitted by certain mosquitoes that occur in and around the home in the Tropics. The yellow fever or dengue mosquito (Aedes aegypti) is the main transmitter of the virus. This mosquito feeds primarily on human blood and bites both during the day and in the early evening.

  • It is important to take measures to protect against mosquitoes during the day and in the early evening in areas where the Zika virus occurs.
  • Cover your skin with clothing (long sleeves, long trousers).
  • Use a mosquito repellent containing DEET on uncovered skin. Children under two and pregnant women should only use products with a maximum of 30% DEET
  • Always sleep under an (impregnated) mosquito net or in a mosquito-free room. 

Travellers with an immune disorder or a chronic illness are advised, as in the case of pregnant women, to seek advice from a GP or a travel clinic before setting off. 

If you have symptoms within two weeks of your return, contact your GP or specialist. There are no vaccines to prevent infection and there are no drugs that will kill the Zika virus. Treatment consists of treating the symptoms. 

Where does Zika fever occur?

The Zika virus was first found in Uganda and Tanzania in 1947. Then it was found in Asia. It then spread to Micronesia (a group of islands in the Pacific Ocean) (2007), to French Polynesia (2013) and towards South America (2015). In the earlier areas the virus probably still circulates regularly among the population. This means that the virus is in fact there but, as far as we know, a lot fewer people become ill than is the case now in South and Central America, as more people have built up a resistance to the virus. The risk of contracting the Zika virus in these countries is therefore probably very small.

Countries where the Zika virus currently occurs

You can find an up-to-date overview of the countries where the Zika virus occurs on the ECDC website. 

It is likely that the disease will spread further in the near future across the (sub)tropical parts of the American continent as a result of intensive travel and the presence of the mosquito that can transmit this virus. This mosquito occurs in the Caribbean region and therefore also on the islands of Bonaire, Sint Eustatius and Saba (BES). These islands have the status of a Dutch municipality. The yellow fever mosquito does not occur in The Netherlands in Europe. So the spread of the Zika virus is to be expected only on Bonaire, Sint Eustatius and Saba.

 

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