What do we know about the Zika virus?

The world was alerted to the situation on the Zika virus spread when the World Health Organisation declared it a public health emergency of international concern on the 1 February 2016.

Zika virus is primarily transmitted to people through the bite of an infected Aedes species mosquito. Mosquitoes become infected when they feed on a person already infected with the virus. There is also evidence which suggests that the virus may also be transmitted from mother to baby during pregnancy or childbirth, from an infected partner during unprotected sex or from blood transfusion.

The Zika virus is transmitted primarily by Aedes aegypti mosquitoes but also Aedes albopictus mosquitoes. The Aedes albopictus mosquito species is established in many parts of the EU, primarily around the Mediterranean, however the risk of transmission of Zika virus infection is extremely low in the EU during the winter season as the climatic conditions are not suitable for the activity of this mosquito. In 2015 and 2016, several travel-related cases have been reported in EU countries in persons who travelled to affected countries but there has been no autochthonous Zika virus transmission reported in the EU and the risk of spread in EU is currently low.

Symptoms of Zika virus infection include: fever, rash, arthralgia, arthritis and conjunctivitis. Symptoms usually develop 3-12 days after being bitten by an infected mosquito and last between 2-7 days. Only 20% infected with the Zika virus have symptoms and there is no vaccine to protect against Zika virus.

There is no specific treatment for Zika virus symptoms. There is evidence to suggest that pregnant women who contract the virus at any point during pregnancy may have an increased risk of giving birth to a baby with microcephaly (this means the baby will have an abnormally small head and can be associated with abnormal brain development).

Preventative measures when travelling to Zika affected zones

People travelling to affected countries are being advised to:

Take measures to prevent mosquito bites.

Women who are pregnant or are trying to become pregnant should postpone travelling to such countries and should avoid getting pregnant while in affected countries.

Pregnant women who have travelled to an affected country must inform their obstetrician on returning home to be assessed and monitored appropriately.

Travellers that have a weakened immune system or severe chronic illnesses should consult their doctor and seek advice before travelling to an affected country.

Practice safe sex in order to avoid getting infected.

People who develop symptoms suggestive of Zika virus infection within two weeks after returning from an affected country should seek medical attention and contact Public Health authorities on the helpline 21324086

Travellers returning from an affected country are advised to use insect repellents for two weeks upon their return and to avoid being bitten and potentially infect the local mosquitoes.

Travellers returning from areas with local transmission of Zika virus are also advised to practice safe sex and use a condom with a female partner at risk of getting pregnant or already pregnant:

− for 28 days after their return from an active Zika transmission area if they have not had any symptoms compatible with Zika virus infection;

− for 6 months following recovery if symptoms were present

The following measures are being recommended to prevent mosquito bites:

  • Protect skin from exposure to mosquitoes by wearing long sleeves, long trousers and hats. Clothing can be treated with an insecticide like permethrin which kills insects.
  • Use mosquito repellent that has DEET as an ingredient in concentrations between 40-50%. It is safe to use during pregnancy and while breastfeeding but only in concentrations less than 50%. This insecticide cannot be used on infants less than 3 months. Repellents need to be applied at regular intervals.
  • Sleeping or resting in screened or air-conditioned rooms otherwise use of insecticide-treated mosquito netting when sleeping is recommended.
  • Eliminate any possible mosquito breeding sites, such as standing collections of water while you are staying in a Zika affected country.