Dengue Fever Overview and Symptoms

Dengue Fever Overview

• Dengue fever is a mosquito-borne illness caused by four related viruses.
• Transmission occurs via the bite of an Aedes mosquito infected with a dengue virus.
• Mosquito infection occurs when it bites a person with dengue in their blood.
• The virus is not spread directly from person to person.
• Globally, around 400 million people are infected annually, with 100 million experiencing mild to severe illness.
• Primarily affects tropical regions (Southeast Asia, Western Pacific, Latin America, Africa).
• Cases in the U.S. are often from travel. Risk is growing in southern U.S. regions.

Symptoms

• High fever
• Severe headache
• Pain behind eyes
• Joint and muscle pain
• Nausea
• Vomiting
• Skin rash

Transmission Cycle

• Infected person is bitten by an Aedes mosquito.
• Mosquito becomes infected.
• Infected mosquito bites others, transmitting the virus.
• Cycle continues, infecting community members through mosquito bites.

Diagnosis

• Diagnosis relies on blood tests.
• Tests may include antibody tests, MAC-ELISA tests, molecular tests (like NAATs and PCR), and complete blood counts (CBCs).
• CBCs detect potential drops in infection-fighting white blood cells and blood clotting platelets (which indicate disease severity).

Dengue Vaccines

• Dengue vaccines have been developed, with the first (Dengvaxia) in 1997.
• Dengvaxia is recommended for those with prior dengue fever or who live in areas with high dengue prevalence; it is given in three doses over six months interval. Approved for 6-45 year olds, though some regions have extended to 9-60.
• A second vaccine (Qdenga) was approved in the EU in 2022 for those with no prior infection. It is administered in two doses over three months, and is approved for those four years and older.

Prevention and Control

• Control mosquitoes that spread dengue, which are primarily active during the day.
• Protective measures to avoid mosquito bites: covering exposed skin with clothing, daytime mosquito nets (ideally treated with repellent), window screens, insect repellents (DEET, Picaridin, IR3535), and coil or vaporizer use.
• Prevention of mosquito breeding:
  • Prevent access to breeding grounds through environmental modification.
  • Properly dispose of waste and remove standing water.
  • Empty, clean, and cover domestic water storage weekly.
  • Apply insecticides to outdoor water storage.

Treatment

• Rest
• Plenty of fluids
• Acetaminophen (paracetamol) for pain
• Avoid NSAIDs (like ibuprofen and aspirin).
• Prompt medical attention for severe symptoms.

This quiz provides an overview of dengue fever, a mosquito-borne illness caused by dengue viruses. Learn about the transmission cycle, symptoms, and global impact of this disease, particularly in tropical regions. Test your knowledge on the fundamental aspects of dengue fever.