US Army, Thai Researchers Close In on Vaccine for Dengue Fever
Prospero Laput | Bangkok 02 January 2009
The World Health Organization reports Dengue fever infects up to 50 million people around the world each year, killing thousands. The disease, common in tropical countries around the world, has undergone a resurgence in the past few decades.
Dengue, no ordinary fever
As dengue potentially threatens the continental United States with reported cases on the Texas-Mexico border, U.S. Army researchers in Bangkok are closing in on a vaccine to conquer this mosquito-borne disease.
It seemed like an ordinary fever, but after Sarapee's son was given medication to reduce his temperature, his nose began to bleed.
"The other hospital gave me the medicine and told me to take him back home," she said. "No blood-test even if he has a high fever. They might have known if they did a blood test."
The doctors did not realize Sarapee's son had dengue fever, also known as "breakbone fever," because victims feel intense joint and muscle pain. Its symptoms are often confused with influenza. But many patients develop a deadly complication called dengue hemorrhagic fever or DHF.
A global health problem
The World Health Organization says more than 20,000 people around the world, mostly children, die each year of DHF, most of them in the tropical developing nations of Africa, Asia and Latin America.
"This kind of disease is endemic in Thailand , so it is like a cycle," Dr. Annutaraskdi Ratchatatat, Thailand-CDC explains. "When the epidemic year comes, the cases rise to more than 100,000 cases per year." Dr. Ratchatatat hopes that one day dengue will be prevented by a vaccine like the one that helped contain polio.
US Army traces disease back 100 years
The United States Army medical corps has been studying dengue for 100 years.
Lieutenant Colonel Stephen Thomas heads the U.S. Army's Dengue Vaccine Development program, in Bangkok. "It was really during World War II when we began to experience dengue virus infection that had a huge impact on the ability of the troops to do their job," he stated. "It was at that time when dengue research in the military and the idea of developing dengue vaccine started to really take off and to blossom."
In this Royal Thai Army building, scientists at the U.S. Armed Forces Research Institute of Medical Science, or AFRIMS, study thousands of blood samples, trying to conquer dengue.
But with four types of virus, it is not an easy task.
"We've had vaccine candidates that we've given to U.S. adults and we said this does not generate any immune response, so we have to throw them away," Thomas said.
Scientists in this facility, the largest U.S. Army medical research laboratory outside the United States, have worked for decades battling dengue.
Treatment, hope in a vaccine
For Thomas, a physician, the motivation to persevere comes from meeting its victims.
"All you need to do is just walk across the street at the Queen Sirikit National Institute of Child Health during dengue season and the dengue ward is filled with children that are suffering from this disease," he said.
The Queen Sirikit Institute is Thailand's foremost dengue treatment center. It is here Dr. Suchitra Nimmannitya developed the dengue diagnostics and treatment manual adopted by the WHO. She works closely with the U.S. Army laboratory, getting early confirmation of her diagnoses. "Our long term collaboration led to more knowledge and understanding of the disease," she said.
Suchitra shares her expertise with other medical professionals. They have confirmed that Sarapee's son has indeed developed DHF, and is in the most deadly stage, called dengue shock syndrome.
Patients in this condition succumb to massive internal bleeding and organ failure if not properly treated. Providing the status on one patient she states: "He received two blood transfusions to correct the nose bleeding. And now his bleeding stopped. He seems to be all right now."
Sarapee is happy that her son is recovering. But doctors say more lives could be saved if only there were a vaccine.
"The disease is increasing everywhere, not just in Southeast Asia. It's a global problem. I think we need the vaccine," Dr. Nimmannitya asserted.
The U.S. Army is testing a possible vaccine in the U.S. and Thailand. But Thomas thinks many questions about how the virus behaves and spreads globally will remain unanswered even with a vaccine, which he says will spur more research and discovery involving the deadly disease.
Source: Voice of America