GENEVA, May 2 (Reuters) - The French overseas territory of La Reunion is experiencing an unprecedented outbreak of dengue fever which could be spread by tourists to other countries, the World Health Organization said on Wednesday.
Dengue is a mosquito-borne virus that may be thriving because of a lack of immunity among the population of the Indian Ocean island, or because the virus is simply causing more symptoms than it did in previous years, the WHO said.
This year there have been 1,816 dengue cases confirmed, as of April 23. All of them were “autochthonous” - local rather than imported by tourists and travellers. In the week to April 23, there were 428 probable and confirmed cases reported, compared to fewer than 100 in all of 2017.
“Although sporadic autochthonous dengue fever cases and clusters have been reported in Réunion before, the upsurge of cases since the beginning of 2018 is unprecedented,” the WHO said.
“Réunion is a popular tourist destination and the likelihood of dengue virus introduction to other countries is heightened by the current outbreak.”
There have been 50 hospitalisations on La Reunion this year compared to 12 in all of 2017, the WHO said.
Officials at the French health ministry were not immediately available for comment.
Dengue is the world’s fastest-growing infectious disease, afflicting hundreds of millions of people worldwide. It causes half a million life-threatening infections and kills about 20,000 people, mostly children, annually.
The world’s only licensed vaccine against dengue, Sanofi’s Dengvaxia, is at the centre of a health scare in the Philippines where the government suspended its use last year amid safety fears.
Last month the WHO said Dengvaxia should only be used after testing on individuals to assess whether they have ever been exposed to the infection.
In 2016, the Haut Conseil de la Sante Publique, a public body close to France’s health ministry advised against the use of Dengvaxia in the country’s overseas territories, Reuters reported in December. (Reporting by Tom Miles; Additional reporting by Matthias Blamont Editing by Susan Fenton)