Dengue fever and dengue hemorrhagic fever (DHF) are a flu-like viral illness transmitted by Aedes mosquitoes, usually Ae. aegypti, that is passed to humans through the bite of a mosquito. Children and infants who become infected with one of the causative viruses may have no symptoms or only a minor, flu-like illness. Adults who become infected may develop a more severe, even life-threatening illness. The four dengue viruses (DEN-1 through DEN-4) are immunologically related, but do not provide cross-protective immunity against each other.
Because this illness may lead to potentially severe complications, you should contact your doctor immediately if you suspect that you have dengue fever.
Causes
There are four types of dengue viruses that can cause this illness. The viruses are carried by Aedes mosquitoes. When an infected mosquito bites a human, the virus enters the individual’s bloodstream and may cause illness. The infection is not passed between humans.
Risk Factors
The following factors increase your chance of developing dengue fever. If you have any of these risk factors, tell your doctor:
Symptoms
Dengue fever is characterized by sudden onset after an incubation period of 3-14 days (most commonly 4-7 days), high fevers, severe frontal headache, and joint and muscle pain. Many patients have nausea, vomiting, and rash. The rash appears 3-5 days after onset of fever and can spread from the torso to the arms, legs, and face. The disease is usually self-limited, although convalescence can be prolonged. Many cases of nonspecific viral syndrome or even subclinical infection occur, but dengue can also present as a severe, sometimes fatal disease characterized by hemorrhagic manifestations and hypotension (DHF/ dengue shock syndrome).
Diagnosis
Your doctor will ask about your symptoms and medical history, recent travel to areas known to harbor dengue fever, and perform a physical exam. Your primary care physician may refer you to a specialist in infectious diseases.
Tests may include the following blood tests:
-
Antibody tests to see if your body is producing substances that fight the dengue fever viruses
-
Reverse transcriptase polymerase chain reaction test (RT-PCR) to determine the presence and quantity of virus present in the bloodstream
Treatment
Acetaminophen products are recommended for managing fever. Acetylsalicyclic acid (aspirin) and nonsteroidal anti-inflammatory agents (such as ibuprofen) should be avoided because of their anticoagulant properties. Patients should be encouraged to rest and take abundant fluids. In severe cases, the prompt infusion of intravenous fluids is necessary to maintain adequate blood pressure. Because shock may develop suddenly, vital signs must be monitored frequently. Hypotension is a more frequent complication of DHF than severe hemorrhage.
Prevention
To help reduce your chances of getting dengue fever, take the following steps when traveling in areas where dengue fever is common:
-
Try to spend your time in locations that are protected by good screens or are air-conditioned.
-
Wear long-sleeved shirts and pants, as well as socks and shoes.
-
Use insect repellants (preferably those containing DEET) on your skin and your clothing.
-
Either stay inside or take extra precautions during the times of day when mosquitoes are most likely to bite (early morning and late afternoon/early evening).
-
Because mosquitoes breed in standing water, do not leave standing water in buckets, flowers pots, or other containers.
RESOURCES:
Centers for Disease Control and Prevention
http://www.cdc.gov
National Institute of Allergy and Infectious Diseases
http://www.niaid.nih.gov/default.htm
CANADIAN RESOURCES:
BC Health Guide
http://www.bchealthguide.org
Capital Health
http://www.cdha.nshealth.ca
References:
Dengue fever. Centers for Disease Control and Prevention website. Available at http://www2.ncid.cdc.gov/travel/yb/utils/ybGet.asp?section=dis&obj=dengue.htm
Dengue fever. National Institute of Allergy and Infectious Diseases website. Available at: http://www.niaid.nih.gov/Factsheets/dengue.htm Accessed July 3, 2005.
Goldman L, Ausiello D. Cecil Textbook of Medicine. 22nd ed. Philadelphia, PA: WB Saunders Company; 2004.
Mandell GL, Bennett J, Dolin R. Principles and Practice of Infectious Diseases. 5th ed. London: Churchill Livingstone, Inc.; 2000.
CDC. Imported dengue —United States, 1999 and 2000. MMWR Morbid Mortal Wkly Rep 2002; 5:281-3.
Ellerin T, Hurtado R, Lockman S, Baden L. Fever in a returned traveler: an "off the cuff" diagnosis. Clin Infect Dis 2003; 36:1004-5, 10-74-75.
García-Rivera EJ, Rigau-Pérez JG. Dengue severity in the elderly in Puerto Rico. Rev Panam Salud Pública/ Pan Am J Public Health 2003; 13:362-8.
Gubler DJ. Cities spawn epidemic dengue viruses. Nature Med 2004; 10:129-30.
Harris E, Pérez L, Phares CR, Pérez MA, Idiaquez W, Rocha J, et al. Fluid intake and decreased risk of hospitalization. Emerg Infect Dis 2003; 9:1003-6.
Kroeger A, Nathan M, Hombach J. Disease Watch: Dengue — Nature Reviews. Microbiology 2004; 2:360-1.
Rigau-Pérez JG, Gubler DJ, Vorndam AV, Clark GG. Dengue: A literature review and case study of travelers from the United States, 1986-1994. J Travel Med 1997; 4:65-71.
