ZikaThe World Health Organization (WHO) has issued a warning regarding the global spread of the Zika virus – which causes microcephaly – after the first detection of it in Cape Verde, Africa.

The announcement comes after sequencing of the virus in Cape Verde by Institut Pasteur, Dakar, confirmed that the virus is the same as the one circulating in the Americas – the Asian type – and was most likely imported from Brazil. This is the first time that the Zika strain responsible for the outbreaks linked to neurological disorders and microcephaly has been detected in Africa.

“The findings are of concern because it is further proof that the outbreak is spreading beyond South America and is on the doorstep of Africa. This information will help African countries to re-evaluate their level of risk and adapt and increase their levels of preparedness,” said Dr Matshidiso Moeti, WHO Regional Director for Africa. 

The announcement by WHO follows a call by the World Federation of Neurology (WFN) Working Group on Zika, which said the spread is “of utmost concern”. As a result, the WFN is developing guidelines for diagnosing Zika-related neurological complications.

Concerned about the increasing number of neurological complications related to the Zika virus, the WFN has recently established a working group to contribute expertise in support of the coordinated global response to the Zika crisis. A large percentage of people suffering from Zika virus infections are asymptomatic or show only mild symptoms. But potential neurological complications can be dramatic. 

“There is a lack of awareness that perhaps more risks are involved in Zika infections than the devastating foetal malformations when Zika is acquired during pregnancy such as the now-familiar microcephaly issue. With major neurological conditions such as Guillain-Barré syndrome (GBS), myelitis, or meningoencephalitis involved in Zika infections, the risks are much broader than originally thought,” said Professor John England from Louisiana State University, New Orleans, who chairs the WFN Zika Work Group. 

In a follow-up to a recent meeting on the public health implications of Zika in Tegucigalpa, Honduras, Professor England and Professor Marco Medina, of the Universidad Nacional Autonoma de Honduras, also a member of the WFN Zika Working Group, agreed on the need for formal guidelines outlining diagnostic criteria for neurological complications of the Zika virus. “We will be working over the next weeks to develop a broad consensus among experts on this,” said Professor England.

With no vaccination in prospect for the time being and lack of evidence about the risk factors influencing the development of neurological symptoms after Zika infection, the focus is now on surveillance, enhanced mosquito control, and prevention, said Professor England. “In particular at a time when thousands of athletes and fans will be travelling to Rio in July, we need to create awareness about the risks involved, and what needs to be done for personal protection.”

As of 11 May, 58 countries and territories report continuing mosquito-borne Zika transmission. Nine countries have reported evidence of person-to-person transmission of the virus.

Warning about the impact in the UK, Professor Paul Hunter, from UEA’s Norwich Medical School, said: “The WHO Europe warning about the risk of Zika virus in Europe is timely and real. There have already been indigenous European outbreaks of two closely related viruses – Dengue and Chikungunya – that are spread by mosquitos. For example an outbreak of Chikungunya occurred in the North East of Italy in 2007 and affected some 217 people and there have been several reports of dengue fever in France in people who had not previously travelled overseas.

“As highlighted by the WHO Europe statement the risk is mostly in southern Europe and especially around the Mediterranean coast. However, even if Zika did start to spread in Europe, it is unlikely to become established as an outbreak is very unlikely to continue over winter. Any outbreak would be relatively short-lived.

“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.

“If and when the disease does come to Europe it will be essential that people are very careful about using insect repellents and use condoms during sex if they think they have been exposed.”