Toronto: With no drugs available for dengue fever and the disease assuming endemic proportions in countries like India and reaching the US for the first time in 40 years, a multi-million dollar study has been launched at Canada's McMaster University to contain the virus.

Prof Mark Loeb of the Michael G. DeGroote School of Medicine at the university has been awarded $10 million by the US National Institutes of Health to conduct a global study on dengue. About 9,000 samples from India, Honduras, Nicaragua, Mexico, Columbia, Thailand, and Vietnam will be brought for analysis.

Dengue kills up to 25,000 people each year worldwide, with the infection spreading from nine to more than 100 countries in the last 40 years. Just last week, the US also reported its first cases of dengue fever in four decades in Florida.

Currently, no vaccines or drugs are available to combat the infection. Caused by the dengue flavivirus transmitted by a mosquito bite, infection can lead to fever, a flu-like condition, to dengue hemorrhagic fever or dengue shock syndrome which can be life-threatening.

"We will get a blood sample from people who have been infected with dengue and compare them to milder cases, looking for genetic variants - such as vitamin D receptors - which have been previously described as important factors,'' said Prof Loeb in a university statement on Thursday. He added, "Dengue used to be endemic in North America. There is concern now that global warming may eventually contribute to a resurgence of dengue.''

During his five-year study, Loeb will concentrate on three distinct groups: individuals infected with severe, hemorrhagic dengue fever, others with milder dengue fever and a third group who are infected but show no symptoms, the statement said.

"We will do comparisons, and then undertake a statistical analysis assessing frequency of genetic variants. The goal is to understand the genetic variants which predispose individuals to dengue,'' the Canadian said.

According to the World Health Organization, about 40 per cent of the world's population lives in areas where there is a risk of dengue transmission. IANS