Dengue fever is a mosquito-borne viral infection caused by the dengue virus (DENV), which is transmitted primarily by the Aedes aegypti mosquito (and less commonly Aedes albopictus).

It is characterized by:

• Sudden onset of high fever
• Severe headache (especially behind the eyes)
• Muscle and joint pain (hence sometimes called “breakbone fever”)
• Skin rash
• Nausea and vomiting

The cause of Dengue fever

1 Dengue virus

• There are four distinct but closely related types (serotypes): DENV-1, DENV-2, DENV-3, and DENV-4.
• Infection with one type gives lifelong immunity only to that type, but not to the others. A person can be infected up to four times.
• A second infection with a different serotype increases the risk of severe dengue.

2 Transmission through mosquitoes

• The main vector is the Aedes aegypti mosquito.
• Less commonly, Aedes albopictus (the Asian tiger mosquito) can also transmit the virus.
• These mosquitoes bite mostly during the daytime (early morning and late afternoon).

3 Human–mosquito–human cycle

• When a mosquito bites a person already infected with dengue virus, it becomes infected.
• The virus multiplies inside the mosquito, and when it bites another person, it injects the virus into their bloodstream, causing infection.

The symptoms of dengue fever

1. High fever – sudden onset, often up to 40 °C (104 °F)
2. Severe headache – especially behind the eyes (retro-orbital pain)
3. Muscle and joint pain – sometimes called “breakbone fever”
4. Nausea and vomiting
5. Skin rash – appears 2–5 days after fever onset, often red and blotchy
6. Fatigue and weakness
7. Mild bleeding – such as nosebleeds, gum bleeding, or easy bruising

Severe dengue symptoms (medical emergency) may include:

• Severe abdominal pain
• Persistent vomiting
• Rapid breathing
• Bleeding under the skin or from organs
• Fatigue or restlessness
• Signs of shock (weak pulse, cold clammy skin)

The treatment for dengue fever

1. Home Care for Mild Dengue

• Rest: Avoid strenuous activity to help the body recover.
• Fluids: Drink plenty of water, oral rehydration solutions, soups, or juices to prevent dehydration.
• Fever and pain relief: Use paracetamol (acetaminophen) for fever and pain.
  ❌ Avoid aspirin or ibuprofen because they can increase the risk of bleeding.

2. Medical Care for Severe Dengue

• Hospitalization may be needed for:
  • Severe dehydration
  • Persistent vomiting
  • Bleeding or low platelet count
  • Signs of shock or organ involvement
• Intravenous (IV) fluids to maintain blood pressure and hydration.
• Blood transfusions in cases of severe bleeding.
• Close monitoring of vital signs, blood counts, and organ function.

3. Prevention of Complications

• Early detection is critical to prevent dengue hemorrhagic fever and dengue shock syndrome.
• Patients should avoid mosquito bites during illness to prevent spreading the virus.