Dengue threatens Asia-Pacific region

Stella Gonzales

Over the past three decades, dengue fever has affected more and more countries in the Asia-Pacific region and is now regarded as the fastest of emerging mosquito-borne diseases. From 1991-2004, a dengue pandemic emerged in the World Health Organisation’s (WHO) Western Pacific region which covers 37 states and areas. It severely affected 10 countries: Vietnam, Malaysia, the Philippines, Cambodia, Laos, Singapore, French Polynesia, Fiji, New Caledonia and China.

Since 2007, there have been an unusually high number of dengue cases in Cambodia, the Philippines, Singapore and Kiribati.

The disease is now so widespread in the region that the WHO estimates that 1.8 billion people

are at risk of contracting dengue. Over the last three months, New Delhi reported 600 cases of dengue of which two were fatal.

The WHO says mortality due to dengue is highest during the initial period of an epidemic, and children are particularly at high risk of death as a result of complications and lack of access to prompt treatment. Even during outbreaks, the WHO says, dengue programmes usually face shortages in human and financial resources. Dengue was one of the major areas of concern discussed by health ministers and representatives from the region during a meeting held in Manila, late September. The delegates agreed that there was a need to find long-term solutions to the problem and reverse the rising trend of the disease.

Participants noted that while some countries have had some success in controlling the spread of the disease, it was the opposite situation in others. Vietnam is one of the countries that have suffered from dengue outbreaks. Dr. Nguyen Huy Nga of the ministry of health said Vietnam started having dengue cases in 1959, and it now averages 50,000 cases a year. The doctor said the ministry has been able to pinpoint the principal breeding areas of the Aedes aegypti, the mosquito species that carries the dengue virus, in containers used by residents to store water in the Mekong Delta.

In Hong Kong, there were no locally acquired dengue cases as of 2003 and infections originated with people who had travelled to South-east Asia and came back home, said Dr. Lawrence Wong Yu-shing of the department of health. The WHO said dengue cannot be controlled if efforts were limited only to a few countries. It said there must be regional collaboration to enable countries to implement measures.

Dr Shigeru Omi, WHO regional director for the Western Pacific, acknowledged that more research was needed on the effects of climate change on health. But, he said, countries

“should not wait for all evidence to be available... and must act now to minimise potential health consequences of climate change with the existing knowledge and technologies available to us.”

During the regional meeting, the participants approved a Dengue Strategic Plan for the Asia-Pacific region that will help countries enhance their preparedness and response and limit epidemics through prevention and control.

Studies show that fatality rates can be reduced to one per cent or less if dengue cases are admitted early and treated appropriately. The strategic plan also recognises the need for vaccine development, improved diagnostics and other innovations for the treatment of dengue.