http://www.cdc.gov/travel/dengfvr.htm

Dengue viruses are transmitted by mosquitoes, which are most active during the day. These vector mosquitoes are found near human habitations and are often present indoors. Epidemic transmission is usually seasonal, during and shortly after the rainy season.

Dengue fever is characterized by sudden onset, high fever, severe headaches, joint and muscle pain, nausea/vomiting, and rash. The rash may appear 3–4 days after the onset of fever. Infection is diagnosed by a blood test that detects the presence of the virus or antibodies. The illness may last up to 10 days, but complete recovery can take 2–4 weeks. Dengue is commonly confused with other infectious illnesses such as influenza, measles, malaria, typhoid, leptospirosis, and scarlet fever. The symptoms of dengue can be treated with bed rest, fluids, and medications to reduce fever, such as acetaminophen; aspirin should be avoided. Travelers should alert their physician of any fever illnesses occurring within 3 weeks after leaving an endemic area. There is no vaccine for dengue fever; therefore, the traveler should avoid mosquito bites by remaining in well screened or air-conditioned areas. Travelers to tropical areas are advised to use mosquito repellents on skin and clothing, to bring aerosol insecticides to use indoors, and use bednets.

The risk of dengue for each geographic area will have variations. The risk is generally higher in urban areas. There are no requirements precluding traveler entry to any country.

Africa
Dengue fever occurs endemically in most of the region and as periodic epidemics. It is found in both rural and urban areas and poses a health hazard to travelers; the risk of infection is highest in urban centers. (Please check the information in the Destinations section on Central Africa, East Africa, North Africa, Southern Africa, and West Africa.)

Southeast Asia and China
Dengue fever occurs endemically in most of the region and as periodic epidemics. It is found in both rural and urban areas and poses a health hazard to travelers; the risk is highest in urban centers. (Please check the information in the Destinations section on Southeast Asia and East Asia.)

Indian Subcontinent
Dengue fever occurs endemically and as periodic epidemics. It is found in both rural and urban areas and poses a health hazard to travelers; the risk is highest in urban centers. (Please check the information in the Destinations section on the Indian Subcontinent.)

The Middle East
Dengue fever is endemic in some urban centers and occurs sporadically in epidemics; the risk of infection is small for most travelers except during periods of epidemic transmission. (Please check the information in the Destinations section on the Middle East.)

South America
Dengue fever occurs endemically in many urban centers and as periodic epidemics. It occurs in both rural and urban areas and poses a health hazard to travelers; the risk is highest in urban centers. (Please check the information in the Destinations section on Tropical South America and Temperate South America.)

Central America
Dengue fever occurs endemically in most urban centers and as periodic epidemics. It occurs in both rural and urban areas and poses a health hazard to travelers; the risk is highest in urban centers. (Please check the information in the Destinations section on Central America.)

Caribbean
Dengue fever occurs endemically in most Caribbean Islands and as periodic epidemics. It occurs in both rural and urban areas and poses a health hazard to travelers; the risk is highest in urban centers. (Please check the information in the Destinations section on the Caribbean.)

Australia and the South and Central Pacific
Dengue fever is endemic with periodic epidemics in parts of northern Queensland and the Torres Strait Islands of Australia as well as most of the South and Central Pacific Islands; there is a risk to the traveler in those specific areas. New Zealand is free of dengue fever. (Please check the information in the Destinations section on Australia and the South Pacific.)

See the CDC Dengue Fever Home Page section for more information on dengue fever.