As dengue fever increasingly becomes a disease of the affluent, especially in Asia, drugmakers are showing more interest in developing treatment, according to a recent report in Nature (subscription required). Dengue fever, a mosquito-transmitted disease that causes severe fever accompanied by joint and muscle pain, infects at least 50 million people a year in more than 100 countries, mostly in the tropics. But unlike many developing world diseases, dengue affects people at all levels of income.

“This is not a disease of the poverty-stricken, rural farmer,” Scott Halstead, scientific director of the Pediatric Dengue Vaccine Initiative in Seoul told Nature. In some developing countries, “the richer you are, the more likely you are to get dengue.” And the weather the afflicted, the more likely a vaccine may be created.

Southeast Asian cities are reportedly experiencing the worst dengue outbreak in a decade: Singapore has more than 5,000 infections while Indonesia has more than 100,000 (with 1,100 deaths). Dengue-carrying Aedes aegypti mosquitoes thrive in urban habitats, breeding in puddles, planters, and old car tires. But with a growing middle class, the infected increasingly have the ability to pay for treatment and, potentially, a vaccine for the so-called “bonecrusher disease.”

“It’s been enormously helpful to the field to see the potential market value of a dengue vaccine increase, and that has everything to do with rising incomes in Latin America and Asia,” Bruce Innis, who heads vaccine development at GlaxoSmithKline (GSK), told Nature. “The reason why GSK and Sanofi-Aventis are in this business is shrewd business judgement.”

Andrew Farlow, an economist at the University of Oxford in the UK, who is working to determine the potential market for a dengue vaccine, says there would be a substantial private market for a dengue vaccine in Asia and the Pacific. And the high economic toll that dengue takes in southeast Asia - $2.4 billion in the next 10 years, according to the World Bank - means that middle- and high-income countries will be willing to pay more.

Until recently, there has been scant financial support for research and development of vaccines and treatments, Nature reports. But coinciding with an economic boom in affected cities, drug companies have begun pumping in money and manpower. Dengue’s immediate potential public and private market is unprecedented, says Harold Margolis, PDVI’s director.

He says that a two-tiered market - public and private - is likely to emerge for the treatment of dengue, one for governments to use for the general public and another for travelers, the military and non-governmental organizations, or NGOs. PDVI is using a $55 million grant from the Bill and Melinda Gates Foundation to support vaccine development and testing.

Some expert say an economic incentive improves the outlook for a vaccine or treatment. “I’d rather be working with a company that feels positive they’re going to get some reward,” Halstead told Nature.

Still, some researchers are skeptical that a vaccine will be developed any time soon. “We’ve been waiting for a vaccine for a very long time,” Michael Nathan, dengue specialist at the WHO, told Nature. Particularly challenging is the need to develop a vaccine that works against at least four strains of dengue.

Hat tip to Mongabay.com