The overall risk of a Zika virus outbreak across the WHO European Region is low to moderate during late spring and summer, according to a new risk assessment published today by the WHO Regional Office for Europe. While this risk varies across the Region, it is higher in countries where Aedes mosquitoes are present.
“The new evidence published today tells us that there is a risk of spread of Zika virus disease in the European Region and that this risk varies from country to country,” says Dr Zsuzsanna Jakab, WHO Regional Director for Europe. “With this risk assessment, we at WHO want to inform and target preparedness work in each European country based on its level of risk. We call particularly on countries at higher risk to strengthen their national capacities and prioritize the activities that will prevent a large Zika outbreak.”
WHO assessed the risk of an outbreak in Member States in the Region and Lichtenstein, based on the combination of two factors: the likelihood of Zika virus spread and existing national capacity to prevent or rapidly contain local transmission.
The likelihood of local Zika virus transmission, if no measures are taken to mitigate the threat, is moderate in 18 countries in the European Region and high in limited geographical areas: the island of Madeira and the north-eastern coast of the Black Sea.
In detail, this means that:
- the areas in the Region with the presence of Aedes aegypti, the primary Zika vector, have a high likelihood of local Zika virus transmission;
- 18 countries (33%) have a moderate likelihood, owing to the presence of Aedes albopictus, a secondary Zika vector; and
- 36 countries (66%) have a low, very low or no likelihood, owing to the absence of Aedes mosquitoes and/or suitable climatic conditions for their establishment.
The results of a questionnaire on capacity – how fast and well a country would respond to Zika virus spread – from 51 Member States in the Region and Liechtenstein indicate that 41 countries (79%) have good and very good capacity, although specific capacities varied substantially.
Combining the likelihood and capacity results provided the estimated level of risk of a Zika virus outbreak. The results show that across the WHO European Region the risk is low to moderate during late spring and summer.