Dengue Epidemic Overshadowed By Bird Flu Fears

by Marwaan Macan-Markar

(IPS) BANGKOK -- For most of his adult life, Dr. Suthee Yoksan has toiled to defeat the mosquito that spreads dengue fever in Southeast Asia.

"It is now 25 years," says the 55-year-old Thai medical researcher of his quest 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.

As agencies including 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."

Meanwhile, the threat of a possible pandemic arising from bird flu and striking the West has triggered the rush for a vaccine for that disease -- and pushed the greater threat from dengue to the background. Avian influenza has killed 62 people since January 2004.

Part of the challenge researchers trying to develop a dengue fever vaccine face comes from the virus they are grappling with. There are four strains that can be transmitted by the carrier mosquito, Aedes aegypti.

"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 center, told IPS. "We should have a cocktail with all four sero-types by end of 2006 or early 2007."

Ratchaburi province, 85 kilometers west of Bangkok along the Thai-Burmese border, has already been singled out for the vaccine trials for all four strains of dengue fever, due to begin 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 immunized 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 hemorrhagic fever (DHF), across Southeast 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 more 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 after 752 cases were reported in the last week of September, twice the number reported during the last week of August.

Malaysia has recorded more than 27,000 cases this year, of which 70 were fatal. But the numbers are still lower than 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, 20 percent higher than last year, including 197 fatalities. In 2004, 144 people died of DHF. And Thailand has accounted for nearly 31,000 dengue cases up to August, including 46 fatalities.

Meanwhile, Indonesia, the latest country to be hit in this region, reports 48,000 cases and 600 deaths.

But the threat extends beyond Southeast Asia, where DHF was first recognized in the 1950s during dengue epidemics in the Philippines and Thailand, according to the World Health Organization.

DHF epidemics were reported in nine countries in 1970. Today, it's 60 countries.

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

Until a potent dengue vaccine materializes, people in Southeast 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 ongoing 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 organizations to government agencies," he adds.