"I think it is exaggerated. It is less alarming than what is being painted in the media," WHO director general Lee Jong-wook told a news conference late on Tuesday.

"If it was a real issue, we would go in the hospitals and see people are dying."

Lee, visiting Mauritius to launch a global report on chronic diseases, said he did not believe the Chikungunya virus was generally fatal.

But he urged local populations to protect themselves by using repellent and removing mosquito breeding areas such as stagnant water pools and rubbish.

The tropical virus, first recognized in Tanzania in 1952, is marked by high fever and severe rashes and can be extremely painful, leaving its victims in a stooped posture. Symptoms can last from seven days to a few months.

The French volcanic island of Reunion has reported 186,000 cases and government officials say there have been 93 deaths which may be partly linked to the virus.

Initial results from clinical research on the island showed 19 percent of women there are carrying the virus, the office of the government's top official on the island said in a statement.

The data suggested that "more than 80 percent of Reunion's population remains at risk of contracting Chikungunya," it said.

Health experts say the tropical virus can weaken the immune system, allowing other deadly diseases to set in.

Neighbouring Mauritius has so far reported 1,500 cases and around 6,000 suspected cases and is awaiting the test results after a 33-year-old man died last month. Officials say the numbers of new cases are declining.

Seychelles has had over 1,000 cases, the French island of Mayotte has had 2,000 cases and Madagascar this week confirmed one case of the virus.

The Indian Ocean islands are concerned the impact the outbreak will have on their vital tourism sectors, but Jong-wook said the WHO would issue a statement to reassure people planning to visit the region.