Waging war against dengue as the Aedes mosquito thrives in a hotter Asia

Updated On: Jul 06, 2007

Much of the Asian continent is on a health alert against the Aedes mosquito (vector carrier of the dengue virus) as it flourishes in this hot and wet region.

The rise of dengue in recent years is said to be exacerbated by global warming. This is especially so in Southeast Asia where dengue cases have reached epidemic proportions. No country is immune– from rich Singapore to impoverished Cambodia.

Already, Singapore has declared a dengue epidemic with its 3,600-odd cases since January 2007 and attempting to tackle the problem with house-checks and fines for mosquito-breeding offenders. Nonetheless, the developed city-state is unsure if it will win this battle. Singapore Health Minister Khaw Boon Wan has warned of an impending “bed crunch” if numbers continue to rise such that non-emergency surgeries will have to be rescheduled, the Today reported.

Things are worse in Cambodia where the rudimentary national health resources are being overwhelmed. Last week Cambodia appealed for international aid as more than a hundred of the 12,700 children who have caught dengue have died. Ngan Chanta, head of the country's anti-dengue programme, told Reuters, “Dengue is hitting almost all provinces nationwide. We cannot contain the virus with our limited resources. We need foreign help.” Neighbouring Thailand swiftly responded to the appeal. Thai PM Surayud has called upon Public Health Minister Mongkol Na Songkhla to lead teams of specialists and carry medical equipment to Cambodia. Xinhua reported that “medical teams will treat Cambodian patients and update Cambodian medical staff on new procedures of preventing and containing dengue fever outbreaks”.

Elsewhere in the region, VietnamMalaysia, and Indonesia, dengue is also at worrying levels. This week, the Jakarta City Council “passed a by-law on dengue fever prevention that calls for integrated preventive measures and sanctions for offenders”, the Jakarta Post noted. Farther afield, India is also trying to curb the surge in dengue by using frogs to eat the mosquito larvae.

If not contained, dengue will not solely be an Asian scourge. The New York Times reported that “dengue has now marched north from Latin America to the southern United States [while] commercial aviation is also carrying infected individuals –and Aedes mosquitoes –to new areas”. This is all the more worrying given that dengue has four viral strains and that there is no vaccine. In addition, Christina Liew, aSingapore medical entomologist, notes that “Aedes mosquitoes are not as fussy about where they will lay eggs as was once believed. In the absence of clean water, females will lay eggs in polluted water as they have learned to adapt to urban situations”.

To add to the dire picture, a meeting of Asia-Pacific health officials this week in Kuala Lumpur has concluded that the region must brace itself for more global warming catastrophes ranging from urban air pollution, flooding, drought, heat waves, malnutrition, and mosquito and waterborne diseases, with a resultant burden on people’s health. The health officials discussed ways to deal with the impending problems on top of the existing issues like HIV/AIDS, tuberculosis and avian flu. Dr. Shigeru Omi, head of the WHO's Western Pacific region, even painted the worst-case scenario in which water scarcity would bring about political instability.

However, Omi said that long-term solutions must be taken to alleviate the symptoms of global warming. He said that “tackling current pressing diseases, and investing more in public health systems overall, will help prepare countries for the future effects of global warming while saving money in the long run”. He added, “The economic impact will be seen eventually. I think it will pay off if we take action now.”


Council passes dengue bylaw, expects enforcement (Jakarta Post, 5 July 2007)

Feeling the strain(Today, 4 July 2007)

Thailand to help Cambodia contain dengue fever (Xinhua, 4 July 2007)

Health alarm as Asia heats(Associated Press, 3 July 2007)

Asia-Pacific countries see effects of climate change on health, brace for more (AP, 3 July 2007)

Singapore urges action as dengue hits epidemic level: report (AP, 3 July 2007)

Health alarm as Asia heats (Associated Press, 3 July 2007)

Dengue fever grips central Vietnam (Thanh Nien News, 2 July 2007)

Cambodia seeks help to fight dengue outbreak (Reuters, 28 June 2007)

Mosquitoes Have the Edge in Singapore’s Dengue War (New York Times, 26 June 2007)