By Marwaan Macan-Markar
BANGKOK , Oct 3 2005 (IPS)

For most of his adult life, Dr. Suthee Yoksan has toiled in the hope of defeating the mosquito that spreads dengue fever in South-east Asia.

”It is now 25 years,” says the 55-year-old Thai medical researcher of a project he has been involved with since 1980 – to develop a vaccine against the disease. And the likelihood of a successful vaccine coming out for public use is still some time away, maybe three years.

Part of the challenge that researchers face comes from the causative virus they are grappling with. For, there are four strains that can be transmitted by the carrier mosquito, Aedes aegypti, when it bites its victim.

”We have a good vaccine candidate for three strains of the virus but need to work on the fourth,” Suthee, director of research at Mahidol University’s vaccine development centre, told IPS. ”We should have a cocktail with all four sero-types by end of 2006 or early 2007”.

Ratchaburi province, some 85 kms west of Bangkok and along the Thai-Burmese border, has already been singled out for the vaccine trials for all the four strains of dengue fever, due to get underway by mid-2007.

”All four cases (strains) of dengue are found in Ratchaburi, so it is ideal,” says Suthee. ”We will be observing children – 5,000 who will be immunised and 5,000 on placebos – for two years before drawing any conclusions”.

The Thai researcher’s determination to stay on course has been matched with the growing potency of dengue fever, including the fatal dengue haemorrhagic fever (DHF), across South-east Asia.

This year, alarm bells have been ringing in most capitals of the region, for both affluent nations like the city-state of Singapore, known for its clean streets and tidiness, as well as poverty-stricken Burma and the chaotic Philippines.

According to public health authorities, Singapore has witnessed nearly 11,000 cases this year, of which 11 have been fatal. That was nearly 1,500 cases higher than the 9,459 cases in 2004 – a record high in the state of 4.2 million people.

Malaysia, the region’s other affluent country, is on the verge of declaring a dengue epidemic in the wake of some 752 cases reported in the last week of September, representing twice the incidence reported during the last week of August.

Malaysia has recorded over 27,000 cases this year, of which 70 were fatal, but the numbers are still lower than the casualty rate in 2004, when there were 33,000 reported cases and 102 deaths.

In the Philippines, on the other hand, nearly 17,340 cases have been reported, which is 20 percent higher than last year, including 197 fatalities. In 2004, there were 144 deaths due to DHF. And Thailand has accounted for nearly 31,000 dengue cases up to August, of which 46 were fatalities.

Meanwhile, Indonesia, the latest country to be hit in this region, there have been 48,000 cases and 600 deaths reported.

But the threat extends beyond South-east Asia, where DHF was first recognised in the 1950s during dengue epidemics in the Philippines and Thailand, states the World Health Organisation.

Its spread over 35 years reveals its potency, since DHF epidemics went from being reported in nine countries in 1970 to 60 countries today.

According to the Geneva-based health body, nearly 50 million people are infected with dengue every year across the world and some 2.5 billion people – two-fifths of the world’s population – are always at risk of being felled by the virus.

Yet, as agencies like the United Nations Children’s Fund (UNICEF) have noted, the ”lack of a market” for vaccines in developing countries has kept companies from investing in research efforts to produce vaccines for ”disease that affects predominantly the poor”.

For developing South-east Asia, it is a reality conveyed in the developed world’s reaction to another disease that has recently spread across the region – avian influenza, which has killed 62 people since January last year.

The threat of a possible pandemic arising from bird flu and striking the West has triggered the rush for a vaccineùand pushed the greater threat from dengue to the background.

Until a potent dengue vaccine materialises, people in South-east Asia appear to have little choice but to be on a perpetual guard against their small, winged menace that breeds in the cities across the region.

”We have to be constantly wary of the dangers of dengue fever, and efforts to eradicate mosquito-breeding cesspools have to be an on-going process, regardless of whether there’s one case or 1,000 in any given area,” writes Paul Yeo in Saturday’s edition of ‘The Star,’ a Malaysian publication.

”Everyone has to be involved, from young children to adults, local councils to state bodies, and non-governmental organisations to government agencies,” he adds.

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