Early monsoons and migration to large cities have encouraged the rapid spread of what World Health Organization (WHO) officials are now calling a dengue fever epidemic in Southeast Asia. To date, there is no cure for the mosquito-borne disease that continues to thrive in both rural and densely populated areas.
Although international healthcare bodies and local governments are adopting programs to educate citizens and offering free treatment to dengue patients, monthly regional outbreaks continue to rise. A near-term solution to the spread of the disease is unlikely, however seasonal changes and international efforts are expected to lessen the number of new cases by the end of the 2007 summer season.
Dengue Fever
Dengue fever is an insect-borne disease transmitted by the Aedes mosquito—it cannot be spread from one person to another. It is endemic to the tropics and often spread from standing water where mosquitoes thrive. As such, humans in Southeast Asia are highly susceptible to contracting the illness during the summer monsoon seasons that offer insects an ideal breeding climate in stagnant puddles, collected rainwater, etc.
Dengue fever causes a variety of symptoms to include: severe headaches and a sudden onset of high body temperature or fever. More serious, developed cases often lead to muscle and joint pain, a decreased white blood cell count, (which incidentally leads to decreased immune system efficacy), and major hemorrhaging. Although death is not always a side effect, fatalities are common among young and elderly patients who succumb to shock, severe blood loss, or a combination of the two.
There are currently four different strains of dengue fever, each with relatively equal transmission rates that increase and decrease in severity per symptoms. The most common symptoms of severe dengue cases, however, include excruciating joint pain and shock usually brought on by severe blood loss.
Trends and Risk Groups
Massive outbreaks in Malaysia, Cambodia, Vietnam, Singapore, and Indonesia have prompted regional fears of a dengue epidemic as the monsoon season climaxes in Southeast Asia. The latest dengue fever epidemic in the region occurred in 1998 with reports of over 350,000 cases and nearly 1,500 deaths.
Although the region experienced its first dengue pandemic following World War II, the disease has continued to spread rapidly since the 1980’s after a period of relative dormancy. An early monsoon season coupled with heavy migration from rural areas to cities has further encouraged transmission. Additionally, increased commercial air travel has offered a new avenue of dengue progression from areas that have little or virtually no mosquito control.
The Future of Dengue Fever
Although dengue fever has mainly afflicted Southeast Asian populations, nearly 20 countries in the Americas have recently reported major outbreaks. The disease’s spread pattern in the Western Hemisphere has been similar to that witnessed in Asia during the 1950’s and 1960’s. Paired with this development, increased awareness of current Asian trends and a growing number of cases has prompted international healthcare and private organizations to establish funding and programs to not only combat a further spread of dengue fever, but also to educate risk groups and cultivate research for cures.
Groups like the Genome Institute of Singapore and the Bill and Melinda Gates-funded Pediatric Dengue Vaccine Initiative (PDVI) have established facilities and opportunities for vaccination research and testing. Additionally, Singapore’s Novartis Institute for Tropical Diseases (NITD) has initiated studies on reducing the severity of the disease following contraction by locating molecule inhibitors. In short, several initiatives have been kick-started in recent years to attack the spread of the disease from every angle, including mosquito population vectoring and control.
Although dengue fever remains a substantial threat to tropical areas, specifically Southeast Asia, many education and research programs are underway to reduce the severity of the disease’s seasonal outbreaks. Current case numbers are expected to decline as the summer and monsoon seasons come to an end, however the long-term outlook remains unclear. In the meantime, tropical regions in both hemispheres are expected to continue to be high-risk areas for indigenous populations and travelers to contract dengue fever.
