Just because we haven't had many cases in the U.S. is no reason to let our guard down. The potential for Dengue 3 to hit is very high. Dengue virus is not new, but one which has re-emerged. The first epidemics were reported in the late 1700s in Asia, Africa and North America. There were long intervals between major epidemics, mainly because the viruses and their mosquito vector could only be transported between population centers by sailing vessels.
Today is a different story.
The North American Free Trade Agreement has created a bigger influx of people moving between borders. The increase in population, especially in Latin America, has led to substandard housing and living conditions. Increased travel by airplane also provides an easy transport for the dengue viruses. According to a Centers for Disease Control and Prevention report, from 1977-94, a total of 2,248 suspected cases of imported Dengue and 481 confirmed cases were reported in the United States. Hayes said that no dengue vaccine is available at the present time.