Dengue is an Emerging Disease
Image: Lab Confirmed cases of Dengue in South America
The four dengue viruses originated in monkeys and independently jumped to humans in Africa or Southeast Asia between 100 and 800 years ago. Dengue remained a relatively minor, geographically restricted disease until the middle of the 20th century. The disruption of the second world war – in particular the coincidental transport of Aedes mosquitoes around the world in cargo - are thought to have played a crucial role in the dissemination of the viruses. DHF was first documented only in the 1950s during epidemics in the Philippines and Thailand. It was not until 1981 that large numbers of DHF cases began to appear in the Carribean and Latin America, where highly effective Aedes control programs had been in place until the early 1970s.