The first cases of Dengue Fever (DF) were recorded in 1779 in Batavia, Indonesia, and Cairo. In 1780, there was an epidemic reported in Philadelphia, PA. For the past 200 years, pandemics have been recorded in tropical and subtropical climates at 10 to 30 year intervals. In 1944, Albert Sabin successfully isolated the virus that causes DF and found that it belongs to the Flavivirdae virus family. There are more than 70 known members of the Flavividae family. Some examples include Yellow Fever and Japanese Encephalitis Virus (3).

Flavivirdae are viruses that utilize humans, lower primates, and mosquitoes as hosts. The dengue virus relies on the mosquito Aedes aegypti as a vector to transmit it to human and primate hosts. Because dengue is thus an arthropod-borne virus, it is also classified as an arbovirus. The A. aegypti mosquito is an urban mosquito that thrives in pools of standing water. Peak transmission is associated with increased amounts of rainfall and mosquito density (3). Therefore, tropical climates are ideal for the mosquito to survive. Pools, puddles, buckets of water, gutters, and people spending a significant amount of time outdoors aid in successful transmission of the virus.

Presently, there are four known serotypes of dengue virus. These are labeled DEN-1, DEN-2, DEN-3, and DEN-4. The different serotypes have the same morphology and genome; however, each serotype displays different antigens. Historically, DEN-2 is the prevalent serotype found in Southeast Asia and may be responsible to immunity against Yellow Fever. DEN-3 has been found in the Caribbean and DEN-1 has been found in the Pacific Islands (Hawaii, Marshall Islands).

Although DF is not a new disease, it can be classified as an emerging disease. Since 1945, the number of reported cases of DF surged because of increased urbanization and travel. The level of endemics also increased. Most alarming, was the emergence of Dengue Hemorrhagic Fever and Dengue Shock Syndrome (DHF/DSS). The first cases of these severe and often fatal diseases were reported in children in Southeast Asia. The emergence of DHF/DSS has been linked with introduction of serotypes into areas of the world in which they did not previously exist (9). For example, DEN-2, characteristic of Asia, was found to be the serotype to cause an epidemic in Jamaica. Until this epidemic, DEN-3 was the only dengue serotype known to exist in the Caribbean. Thus, because of increased numbers of infected peoples and the increased severity of the disease, DF is a focus of concern for many epidemiologists.