Dengue is primarily a disease of the tropics, and the viruses that cause it are maintained in a cycle that involves humans and Aedes aegypti, a domestic, day-biting mosquito that prefers to feed on humans. Infection with dengue viruses produces a spectrum of clinical illness ranging from a nonspecific viral syndrome to severe and fatal hemorrhagic disease. Important risk factors for dengue hemorrhagic fever include the strain and serotype of the infecting virus, as well as the age, immune status, and genetic predisposition of the patient.
The first reported epidemics of dengue fever occurred in 1779-1780 in Asia, Africa, and North America; the near simultaneous occurrence of outbreaks on three continents indicates that these viruses and their mosquito vector have had a worldwide distribution in the tropics for more than 200 years. During most of this time, dengue fever was considered a benign, nonfatal disease of visitors to the tropics. Generally, there were long intervals (10-40 years) between major epidemics, mainly because the viruses and their mosquito vector could only be transported between population centers by sailing vessels.
A global pandemic of dengue began in Southeast Asia after World War II and has intensified during the last 15 years. Epidemics caused by multiple serotypes (hyperendemicity) are more frequent, the geographic distribution of dengue viruses and their mosquito vectors has expanded, and dengue hemorrhagic fever has emerged in the Pacific region and the Americas. In Southeast Asia, epidemic dengue hemorrhagic fever first appeared in the 1950s, but by 1975 it had become a leading cause of hospitalization and death among children in many countries in that region.
Important and Helpful Links
Medical Entymology: Everything you ever wanted to know about bugs and their diseases from the department of medical entymology at University of Sydney and Westmead Hospital, Australia.
Mosquito Facts: Some interesting facts about the world's most hated insect.
AMCA: The American Mosquito Control Association. Individuals enhancing the health and quality of life through the suppression of mosquitoes, other vectors and pests of public importance.