More than 13,000 people in southern Vietnam have contracted dengue fever already this year, and 11 of them had died as of May 3, the director of the Pasteur Institute in Ho Chi Minh City said Friday.

Dengue is no longer restricted to the rainy season and could strike at any time of the year, he said.

Unsurprisingly, it is among the top five infectious diseases with the highest numbers of cases and deaths in Vietnam.

The poor drainage in slum areas, a result of the country’s urbanization and industrialization, along with the warm climate create the ideal conditions for dengue fever to break out.

There is no commercial vaccine to protect against dengue yet, but several vaccines are at the experimental stage, Huu said.

The Pasteur Institute is working with Sanofi-Pasteur, the vaccines division of Sanofi-Aventis Group, to carry out clinical studies of Sanofi’s tetravalent dengue vaccine, which is also being trialed in Thailand, the Philippines and Singapore.

If the trials yield good results, a novel vaccine against dengue will be available in 2015 or 2016, said Wartel Nguyen N.T. Anh, SanofiPasteur’s regional medical director of clinical development.

The mosquito-borne disease, which is caused by any of four viruses, infects an estimated 230 million people annually and is a potential threat to almost half the world’s population, according to Sanofi-Aventis.

Reported by Van Khoa