ECDC publishes an updated rapid risk assessment on Zika virus disease epidemic and potential complications

Today ECDC publishes an updated risk assessment on the Zika virus disease epidemic and the potential associations with microcephaly and Guillain-Barré syndrome. The epidemic continues to evolve rapidly in the Americas. Since the last update, eight new countries have reported autochthonous transmission: American Samoa, Costa Rica, Curaçao, Dominican Republic, Jamaica, Nicaragua, Tonga and the US Virgin Islands. Thirty-five countries or territories reported autochthonous cases of Zika virus infection within the past nine months.

The evidence regarding a causal link between Zika virus infections during pregnancy and congenital central nervous systems (CNS) malformations is substantial. Cases of Guillain-Barré syndrome (GBS) are continuing to be reported from the affected countries but since the publication of the previous risk assessment, no new scientific evidence regarding the association between Zika virus and the GBS and Zika virus infection has been published. There is new evidence that Zika virus can be transmitted sexually through semen, and that the virus may be present in semen for several weeks after a man has recovered from a Zika virus infection.

The strongly suspected association between Zika virus infection and congenital malformations as well as between Zika virus infection and GBS justify the need to consider preventive measures to reduce the risk of transmission to people who plan to visit Zika affected areas. The population most at risk of negative health outcomes from Zika virus infection are pregnant women. They are advised to discuss their travel plans and evaluate the risk with their healthcare providers, and to consider postponing their travel.

Options for mitigations

The main options for mitigation that public health authorities in EU/EEA Member States should consider include the following (see the rapid risk assessment for the full description of the options): 

Surveillance

• Increase awareness of clinicians and travel health clinics about the evolution of the Zika virus outbreak and the affected areas.
• Enhance vigilance towards the early detection of imported cases of Zika virus infection in EU Member States, EU Overseas Countries and Territories, and EU Outermost Regions, in particular where vectors are present, in order to reduce the risk of autochthonous transmission.
• Strengthen laboratory capacity to confirm suspected Zika virus infections in the European region.
• Increase awareness among obstetricians, paediatricians and neurologists in the EU/EEA.

Information to travellers

• Travellers visiting countries where Zika virus is currently being transmitted should use personal preventive measures based on protection against mosquito bites indoors and outdoors. Such measures include:
• Use mosquito repellent in accordance with the instructions indicated on the product label.
• Wear long-sleeved shirts and long trousers, especially during the hours when the type of mosquito that carries the Zika virus (Aedes) is most active.
• Sleep or rest in screened or air-conditioned rooms, otherwise use mosquito nets, even during the day.
• Pregnant women and women who are planning to become pregnant, and who are intending travel to affected areas, should discuss their travel plans and evaluate the risk with their healthcare providers and consider postponing their travel.
• Travellers with immune disorders or severe chronic illnesses should consult their doctor or seek advice from a travel clinic before travelling, and be given advice on effective prevention measures.
• Travellers showing symptoms compatible with Zika virus disease within three weeks of return from an affected area are advised to contact their healthcare provider and mention their recent travel.
• Pregnant women that have travelled in areas with Zika virus transmission should mention their travel during antenatal visits in order to be assessed and monitored appropriately.
• Male travellers returning from areas with local transmission of Zika virus should consider using a condom with a female partner at risk of getting pregnant or already pregnant:
• for 28 days after his return from an active Zika transmission area if he has not had any symptoms compatible with Zika virus infection;
• for 6 months following recovery of a laboratory confirmed Zika virus infection.

Safety of substances of human origin

Persons with diagnosis of Zika fever may be accepted for blood donation 28 days after cessation of symptoms. Competent authorities, establishments and clinicians dealing with blood supply need to be vigilant and aware of the risk of donor-derived Zika virus transmission through transfusion.