Dengue fever is an infectious tropical disease caused by the dengue virus. Symptoms include fever,headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases the disease develops into the life-threateningdengue hemorrhagic fever, resulting in bleeding, low levels of blood platelets and blood plasma leakage, or into dengue shock syndrome, where dangerously low blood pressure occurs.
On this subject, there is an interesting article from Emerging Infectious Diseases.
Dengue Outbreak in Key West, Florida, USA, 2009, Elizabeth G. Radke, et al.
For more than 60 years, no cases of dengue had been acquired in the continental United States outside the Texas-Mexico border; therefore, a reported suspect case in Florida in 2009 was cause for concern. An investigation, consisting of a survey and blood testing, found 13 Key West residents in the sampled area who had been infected with dengue virus in 2009 and reported no travel outside the United States. From the survey results, researchers estimated that 5 percent of people in the surveyed area had been infected, which would mean that more infections occurred in 2009 than were reported. Factors that put people at risk for dengue infections included having windows frequently open, using air conditioning less frequently and having yards with large amounts of vegetation or bird baths. Preventing future cases will require personal protection against mosquitoes, mosquito control, early diagnosis, appropriate testing, and prompt reporting of suspected cases. A total of 27 and 66 cases of locally acquired dengue were reported in Key West in 2009 and 2010, respectively. There were no cases of locally acquired dengue in 2011, which is indicative of the success that local health authorities, mosquito control and the public are having in controlling dengue in Key West.
Reference: Emerging Infectious Diseases Journal Vol. 18, No. 1, (January 2012)