Why exactly are scientists willing to take the risk now? The major reason is the spread of dengue. It has increased 30-fold in the past 50 years, and has spread from just a few countries in the 1950s to over 60 countries today. There are over 22,000 deaths every year due to dengue. At this point, it is essential to conduct more research on dengue to see which strains cause illness in individuals and study them in order to give people around the world better treatment and prevention options.