Dengue fever is a flu-like viral disease common throughout the tropical and sub-tropical regions around the world, mainly in urban and peri-urban areas. Today, it afflicts an estimated 50 million to 100 million in the tropics (Epstein, 2000). The virus has four antigenically related serotypes, which are named DEN-1, DEN-2, DEN-3, and DEN-4. Each dengue serotype is a variation of the flavivrus genus. Dengue is spread by the aedes aegypti, a domestic, day-biting mosquito that prefers to bite humans. Currently, there is no vaccine available to prevent dengue. .
Each type of the dengue virus is re-emerging worldwide, especially in the Western Hemisphere. Research has shown that several factors are contributing to the resurgence of dengue fever such as uncontrolled urbanization, increased international travel, substandard socio-economical conditions, and finally global warming. Global warming has shown to be a major contributor to the spread of dengue fever.
On a molecular level, dengue fever is classified as a flavivirus and appears as a spherical particle, about 40 to 50 nanometers in diameter (www.malarde.pf.). There is a lipid envelope enclosing a nucleocapsid core (www.malarde.pf/.). The dengue virus genome is a single-strand positive sense RNA of approximately 11 kilobases (www.malarde.pf/.). The mature virions contain three structural proteins: C (capsid), prM (membrane) and E (envelope) and 7 nonstructural proteins (www.malarde.pf/.). .
Once a person is infected by dengue fever, symptoms will start to appear anywhere from four to six days after the pathogen has been transmitted from the infected mosquito to the person (http://astdhpphe.org.). The virus can not be spread from an infected person to another person. However, if another mosquito bites the infected person, the virus can be transmitted to another person through that newly infected mosquito. The infected person remains a viral source for other mosquitoes for about 6 days (http:///astdhpphe.