The most common severe manifestation of infection is Dengue Hemorrhagic Fever (DHF), first recognized in the 1950s during the dengue epidemics in the Philippines and Thailand. By 1970 nine countries had experienced epidemic DHF and now, the number has increased more thanfourfold and continues to rise. Today, DHF has become an emerging problem throughout much of the Americas as well as in Asia. It has become a leading cause of hospitalization and death among children in several countries.
The spread of dengue is attributed to expanding geographic distribution of the four dengue viruses and their mosquito vectors, the most important of which is the predominantly urban species Aedes aegypti. A combination of factors including increased global travel, reduced vector control efforts, increased urbanization, and increased recognition of the disease are likely key determinants of the recent rise in global incidence.
In collaboration with the Centers for Disease Control and Prevention Dengue Branch, HealthMap has created a guide for the assessment of dengue risk throughout the world.
Dark blue regions on the map represent areas of ongoing transmission risk as defined by the CDC based on data from Ministries of Health, WHO and other international health organizations, journals, and knowledgeable experts (last updated in 2008 for the CDC Yellow Book). Recent reports of local and regional dengue transmission collected by HealthMap are shown as red markers with links to the respective reports. A lack of recent reports for any given area does not indicate that no transmission is occurring, particularly in the many risk map areas where dengue is endemic.