Well, Dengue is not a really big and deadly virus. Just like swine flu. Influenza/Fever still kills more people than these two. Remember the the outcry when Swine flu and bird flu came.
I have realtives who got infected by dengue. She works at Jinnah hospital as a house job doctor. She gotit, but if treated promptly , then it is nothing. Neither is swine flu or bird flu. Now, the diagnosis period is to be taken into consideration. Fever has a longer, Influenza still longer, but Dengue has less than both of those. Now, if you dont treat any disease in time, you die.
Stop making these theories. Unhygienic places are the cause.