SINGAPORE - The dengue virus-carrying Aedes mosquito has adapted to urbanized human environments and traditional methods used in most Asian countries to control their breeding may no longer be as effective, a panel of experts meeting in Singapore said Saturday.
"It's a global pandemic," said Dr. Duane Gubler, director at the Asia-Pacific Institute of Tropical Diseases in Hawaii. "It's quite clear that the disease...has evolved. There just is more dengue in the world."
All across Asia, governments are scrambling to contain the virus, which is only carried by the Aedes mosquito.
Singapore has already recorded more than 11,000 cases this year alone, far more than the then-record of 9,459 set in 2004. Neighboring Malaysia meanwhile, has reported close to 28,000 human infections — more than 25 percent compared to a year ago.
Philippines and Thailand are also battling a rash of infections.
The world is no longer battling "a war with armies but a war with guerillas" in dealing with mosquitoes, said Dr. Paul Reiter, an infectious diseases expert from the Pasteur Institute in France.
Both Reiter and Gubler were part of the panel of experts asked by Singapore's Ministry of Health to help find a reason for its current spike.
Dengue is sometimes called bone-breaker's disease because it causes severe joint pain. Other symptoms include high fever, nausea, and a rash. In the worst cases it causes internal bleeding. There is no known cure or vaccine.
"The increase in dengue cases in Singapore may include the importation of new strains of the virus with GREater epidemic potential," the panel said in its report.
The U.S. Centers for Disease Control and Prevention considers dengue the "most important mosquito-borne viral disease affecting humans" this year — ahead of malaria and encephalitis — with an estimated 2.5 billion people at risk worldwide.
"It's a mosquito that used to breed in tree holes, but it has adapted to the human environment," said Reiter.
"The bottom line is that you are as successful as Singapore, you've (also) become vulnerable," said Reiter, referring to a possibility that the population now has a lower threshold to such infections.
Singapore, a highly-urbanized Southeast Asian city-state of 4.2 million, has relied on mass aerosol spraying, or fogging, to bring down mosquito numbers for decades, a method which researchers say have worked. It's also widely used in a number of other countries, including the United States.
But Gubler said such methods may now be less effective than before, and are also dependent on a number of factors, including wind and the concentration of the chemical mix.
