Mosquito-Borne Illness: Dengue Virus or Dengue Fever

Dengue fever is a potentially deadly disease that is carried by humans and mosquitoes that are infected with human blood containing the dengue virus. It is most commonly transmitted to humans through mosquito bites, and secondarily to humans from blood transfusions infected with the virus. Dengue virus is found in four different serotypes, as dengue 1-4, and it is moderately similar genetically to yellow fever.

What Can Occur When Infected with the Dengue Virus

Milder cases of dengue virus infection result in dengue fever, while more serious cases result in dengue hemorrhagic fever and dengue shock syndrome. Dengue fever begins to present itself as flu like symptoms, rash, pain and soreness for a period of two to ten days. A person who has traveled anywhere tropical and feels suddenly flu-like after being bitten by mosquitoes should consult their healthcare provider right away to ensure recovery.

Aedes Mosquitoes

Aedes (Stegomyia) mosquitoes carry and transmit dengue fever. In Hawaii, the Aedes aegypti (Yellow Fever Mosquito) and Aedes albopictus (Asian Tiger Mosquito or Forest Day Mosquito) are prevalent. Other Aedes members can transmit dengue, but are not found in Hawaii. These mosquitoes are most active in the early morning after sunrise and the late afternoon before sunset.

Where Dengue Fever is Most Prevalent

Millions of cases of dengue infections occur every year, especially in Asia, the Pacific, the Caribbean, areas of the Americas and Africa. The highest number of cases are found in Southeast Asia and the western Pacific islands, but the transmission of dengue is spreading throughout the world where Aedes mosquitoes are found.

There is no vaccine for dengue fever and prevention is the key to fighting infections. It is important to use mosquito repellent containing DEET, especially in areas that have a high Aedes mosquito population.

Signs and Symptoms of Dengue Fever

In mild cases of a dengue infection, many people won’t even notice or show signs or symptoms. The virus will simply run its course and the person won’t know they were ever infected. In cases where symptoms occur, it’s important to know that symptoms generally begin 4 to 10 days after being bitten by an infected mosquito. Symptoms of dengue fever include:

  • High fevers, up to 106 degrees Fahrenheit
  • Headaches that are difficult to relieve
  • Severe pain behind the eyes
  • Pain throughout the muscles, joints and bones
  • Upset stomach, vomiting
  • A rash spread throughout the body
  • One uncommon symptom is minor bleeding in the gums or a nose bleed


There is no specific treatment for dengue fever. If symptoms appear, you should visit your healthcare provider immediately for testing. Your doctor may suggest over-the-counter pain relievers and fever reducers, such as acetaminophen (Tylenol), to help keep your symptoms under control. Aspirin and NSAIDS (ibuprofen, naproxen) are not recommended as they can make bleeding problems associated with dengue fever worse. You will also need to rest and drink plenty of fluids to reduce your chances of dehydration. For severe cases of dengue fever, hospital care may be required to monitor symptoms and keep them in check.

For dengue hemorrhagic fever, hospitalization will likely be required to monitor blood pressure and to get -blood transfusions as a result of blood loss. Dengue fever can be recurrent, and people who have been infected previously with dengue virus are more susceptible to getting a more severe case of dengue fever the second time around.

For more information about dengue, visit the Disease Outbreak and Control Division’s section of the Hawaii Department of Health’s website at