According to the European Centre for Disease Prevention and Control, three cases of Zika were confirmed in Hyères, a French Riviera town in southern France in August this year.
It was determined the Zika virus had been acquired locally rather than being brought into the country by travelers. This is completely different from the approximately 2,400 cases of Zika detected in Europe since 2015, when the outbreak in South America took off. Those cases were brought into Europe by tourists visiting other continents.
An interesting aspect of the three cases is that they all occurred around the same time, leading investigators to believe they were all part of the same transmission cycle. All three of the victims have recovered and the health authorities say the risk to residents and travelers to the region is low.
“It’s one thing for travelers to come back to a country with a disease, that happens all the time,” Professor James Logan, head of the department of disease control at the London School of Hygiene and Tropical Medicine, told The Telegraph.
“It’s another thing completely when a disease is transmitted locally as it demonstrates capacity. We now have a new exotic disease in Europe,” he said. “In many ways, this is a bit of a wake-up call for the continent.”
The usual mode of transmission for the Zika virus is the Aedes aegypti mosquito. However, this mosquito isn’t usually found in southern Europe. But Moritz Kraemer, a researcher into infectious diseases at the University of Oxford tells CNN that another mosquito, Aedes albopictus – the Asian tiger mosquito – has now become common.
The Asian tiger mosquito “has become common in parts of southern France, where it has probably also been responsible for the transmission of dengue. It has also been detected widely throughout southern Europe and sporadically further north,” said Anna Checkley, a consultant in Tropical Medicine at the Hospital for Tropical Diseases.
“Warmer temperatures favor its survival, and as we go into winter it is much less likely that we will see further new cases. (But) if global temperatures increase, this mosquito may spread further north in Europe and we may see small clusters of cases further north.”
There is a concern that a warming climate will make more regions in the Northern Hemisphere open to tropical diseases – just as Dengue and now, Zika, have made their way to southern Europe. Another concern is that the number of cases is already probably under-reported – posing challenges to their control.
The Zika virus is generally a mild virus, causing fever, rash or headache – although most people infected will never develop symptoms. The real danger associated with this virus is women who may be pregnant or want to get pregnant – as the virus can cause microcephaly, a neurological disorder that results in babies being born with abnormally small heads, which in turn can cause severe developmental issues and even death.