Overview

Dengue fever is a viral infection transmitted to humans through the bite of infected mosquitoes, primarily the Aedes aegypti mosquito. It is common in tropical and subtropical climates worldwide. While many dengue infections are asymptomatic or produce mild illness, it can sometimes evolve into a severe, life-threatening condition called severe dengue (previously known as dengue hemorrhagic fever).

Symptoms

Symptoms of dengue typically begin 4–10 days after the bite from an infected mosquito and can last for 2–7 days. Common symptoms include:

• High fever (40°C/104°F)
• Severe headache
• Pain behind the eyes
• Muscle and joint pains
• Nausea and vomiting
• Swollen glands
• Rash

Warning signs for severe dengue, which is a medical emergency, often begin after the fever has subsided and include:

• Severe abdominal pain
• Persistent vomiting
• Rapid breathing
• Bleeding gums or nose
• Fatigue and restlessness
• Blood in vomit or stool

Causes

Dengue is caused by the dengue virus (DENV), which has four distinct serotypes (DENV-1, DENV-2, DENV-3, and DENV-4). You can be infected with each serotype once in your lifetime. The virus is transmitted through the bite of female Aedes mosquitoes. These mosquitoes are most active during the daytime, particularly in the early morning and late afternoon.

Prevention

The best way to prevent dengue fever is to avoid being bitten by mosquitoes. Key prevention strategies include:

• Use Insect Repellent: Apply repellents containing DEET, picaridin, or oil of lemon eucalyptus to exposed skin.
• Wear Protective Clothing: Wear long-sleeved shirts, long pants, socks, and shoes.
• Mosquito-Proof Your Home: Use window and door screens, and air conditioning if available. Sleep under a mosquito net.
• Eliminate Breeding Sites: Aedes mosquitoes breed in standing water. Regularly empty, clean, or cover containers that can hold water, such as buckets, tires, flower pots, and gutters.

Treatment

There is no specific medication to treat dengue fever. Treatment focuses on relieving symptoms:

• Rest and Hydration: Get plenty of rest and drink lots of fluids to prevent dehydration.
• Pain Relief: Take paracetamol (acetaminophen) to control fever and pain. Avoid non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and aspirin, as they can increase the risk of bleeding.
• Medical Care: For severe dengue, medical care by physicians and nurses experienced with the effects and progression of the disease can save lives — decreasing mortality rates from more than 20% to less than 1%. It is crucial to seek immediate medical attention if you experience any of the warning signs.