GENEVA: 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, the WHO said, adding the virus may also have spread unnoticed in recent years as asymptomatic cases may have contributed to the transmission cycle.

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 Reunion before, the upsurge of cases since the beginning of 2018 is unprecedented,” the WHO said. “Reunion 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.

Published in Dawn, May 3rd, 2018