“The likelihood of local Zika virus transmission, if no measures are taken to mitigate the threat, is … high in limited geographical areas: the (Portuguese) island of Madeira (off Africa) and the northeastern coast of the Black Sea,” WHO said.
The reason for the high-level threat in those areas is the presence of the Aedes aegypti mosquitoes, which carry the Zika virus that causes birth defects if contracted by a woman during pregnancy, the UN global health agency said.
Another 18 countries in Europe “have a moderate likelihood” of a Zika virus outbreak, WHO warned.
“The overall risk of a Zika virus outbreak across the WHO European Region is low to moderate during late spring and summer,” it said.
That was largely due to the presence of another mosquito species in those countries, the Aedes albopictus, which is less likely to cause outbreaks than its cousin in Latin America and the Caribbean, according to research by the Pasteur Institute.
Within the “moderate likelihood” group, France, Italy and Malta had the top three transmission likelihood scores.
The score was based on factors including climatic suitability for the mosquitoes, shipping and air connectivity, population density, urbanisation and history of previous outbreaks of viruses transmitted by insects or other animals.
“With this risk assessment, we at WHO want to inform and target preparedness work in each European country based on its level of risk,” said Dr Zsuzsanna Jakab, WHO regional director for Europe.
“We call particularly on countries at higher risk to strengthen their national capacities and prioritise the activities that will prevent a large Zika outbreak.”
No winter outbreak –
Paul Hunter, a professor of health protection at Britain’s University of East Anglia, said in a statement that any outbreak in Europe would be “relatively short-lived” since it was “very unlikely to continue over winter.”
“Nevertheless an outbreak occurring in the Mediterranean area could still have repercussions throughout Europe if pregnant holidaymakers acquire the infection, or if males then pass the infection sexually to their pregnant partners,” he said.
Another expert-Derek Gatherer, a lecturer at Lancaster University’s Division of Biomedical and Life Sciences-said the wealth and infrastructure of developed countries made them less susceptible to mosquito-borne diseases.
“The ideal stagnant water habitat of the mosquito larva is less present in our cities; our houses are less likely to have many indoor insects; we can afford insect repellents and other devices for keeping fly numbers down and so on,” he said.
“It is worth remembering that mosquito-borne diseases were more prevalent in Europe in the past,” he added.
Recent scientific consensus is that Zika causes microcephaly, a form of severe brain damage in newborns, as well as adult-onset neurological problems which can lead to paralysis and even death.
There is no vaccine or treatment for the virus, which in most people causes only mild symptoms-a rash, joint pain or fever.
Brazil has been the epicentre of the Zika outbreak now affecting 58 countries and territories, with around 1.5 million people infected in the country since 2015.
The WHO last week urged pregnant women not to travel to Rio for the Olympics and told athletes and visitors to the Games to take precautions to avoid the infection.
Those making the trip to the Olympics and Paralympics, set for August 5 through September 18, should wear body-covering clothing and insect repellant, and avoid visiting impoverished and overcrowded areas with poor sanitation where the risk of mosquito bites is higher, it said.