London School of Hygiene & Tropical Medicine

The overall risk of a Zika virus outbreak across Europe is low to moderate during late spring and summer, according to a new risk assessment published by the World Health Organization (WHO).

Risk was 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 assessment reported that if no measures are taken to mitigate the threat, the likelihood of the virus transmitting is moderate in 18 countries, including France and Italy, and high in the island of Madeira and the north-eastern coast of the Black Sea.

So what does this mean for the UK and how worried should holidaymakers be who are travelling to areas identified as a potential risk? Jimmy Whitworth, Professor of International Public Health, explains:

"This is a comprehensive, important and timely risk assessment by the WHO, which compliments the risk assessments done previously by European Centre for Disease Control, and the UK-specific risk assessment by the HAIRS group.

"Summer is approaching fast and the risk of Zika spreading to Europe is real. The main mosquito vector for Zika, Aedes aegypti, is only found in Madeira and around the Black Sea, but another mosquito, Aedes albopictus, is more widespread and is capable of transmitting Zika, although not very efficiently. It is possible that Zika virus could be introduced into European Aedes albopictus and cause outbreaks this summer or in future years.

"WHO reports that most countries in the European region are well prepared to protect their populations from the spread of Zika. This includes effective surveillance and a plan for the control of Aedes mosquitos with clear lines of responsibility and a designated budget, and also heightened clinical awareness and surveillance for human cases of Zika infection including laboratory capacity for diagnosis.

"The risk to the UK is very low. The mosquitos that spread Zika are not found naturally in the UK - our climate is too cold, even in summer. However, a UK- wide contingency plan for invasive mosquito control should be developed. This infection is a travel-associated risk for the UK, and the Government has issued clear travel advice. There are however no travel restrictions in force. The advice includes how to reduce the risk of sexual transmission of infection from returning travellers. A few isolated cases in returning travellers have been seen in the UK already, but there is virtually no chance of there being an epidemic here.

"However, countries in Southern Europe, including France and Italy, need to be especially vigilant and it's important that holidaymakers follow public health advice while abroad, including taking all the necessary precautions to avoid getting bitten. This is especially so for pregnant women, or women planning to become pregnant, travelling to areas where there is Zika, as there is now a proven link with microcephaly and other birth defects."

Related links:

• Short course on Preventing the Zika Virus
• School Zika virus research
• Previous expert comment on the Zika virus outbreak in the Americas
• Media highlights: Latest comment from our experts in the news
• Seminar recording: Prof Laura Rodrigues on the epidemic of microcephaly in Brazil