Dengue and Dengue Hemorrhagic Fever are acute febrile viral diseases. There are four different dengue viruses (DEN-1, DEN-2, DEN-3, and DEN-4) that cause illness. Disease is characterized by the sudden onset of fever, severe headache, joint and muscle pain, GI disturbances, and rash, and in the hemorrhagic manifestation, bleeding from multiple sites. The sporadic occurrence of shock and hemorrhage typically results in death.

Dengue is predominantly a disease of tropical urban areas and maintained in a human- Aedes aegypti mosquito cycle (a monkey-mosquito cycle may be important in maintaining the virus in Asia and Africa). There are an estimated 50 to 100 million cases in the world each year, and although there has not been an outbreak in the continental United States since 1945 there are approximately 200 suspect cases imported annually to the U.S. by international travelers. The majority of these imported cases occur in Florida and Texas; however, Hawaii experienced an outbreak in 2001, which was attributed to local transmission. While the incidence of dengue is low in the continental U.S. and surveillance is passive based on reported cases, Puerto Rico and the U.S. Virgin Islands have active, laboratory-based surveillance programs in place to control the increasing incidence in the Americas.

Risk Reduction

Effective risk reduction for mosquito-borne diseases within the NPS requires all employees and visitors to be knowledgeable and proactive in taking necessary steps to minimize exposure. Primary risk reduction practices include eliminating man-made mosquito-breeding habitat, avoiding activities when mosquitoes are most active, and wearing long sleeved shirts and pants. Many species of mosquito breed in stagnant water, therefore, it is critical that containers such as tires, buckets, birdbaths, gutters and miscellaneous debris are either removed or not holding water. The use of an insect repellant containing DEET, picaridin or oil of lemon eucalyptus (p-menthane or PMD) are effective against mosquitoes and should be used during periods of high mosquito activity. DEET should be used with caution on children – DEET is not recommended for the very young. Products containing oil of lemon eucalyptus should not be used on the very young.

References

Health Information, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Department of Health and Human Services.