Dengue fever is a mosquito-borne viral infection that affects millions of people every year, particularly in tropical and subtropical regions. While many cases are mild, dengue can also lead to serious complications that threaten lives if not properly managed. Understanding the disease, its symptoms, and its potential complications is essential for early detection, timely treatment, and prevention.
What is Dengue Fever?
Dengue fever is caused by the dengue virus, which is transmitted primarily through the bite of infected Aedes aegypti and Aedes albopictus mosquitoes. These mosquitoes are daytime feeders and thrive in urban areas with standing water where they can breed. There are four types of dengue virus (DENV-1, DENV-2, DENV-3, and DENV-4). A person can be infected multiple times in their lifetime, but subsequent infections increase the risk of severe illness.
The World Health Organization (WHO) estimates that around 390 million dengue infections occur annually, with about 96 million showing clinical symptoms. This makes dengue one of the most widespread mosquito-borne diseases in the world.
Symptoms of Dengue Fever
Dengue symptoms typically appear 4 to 10 days after being bitten by an infected mosquito. The illness can range from mild to severe.
Common Symptoms
- Sudden high fever (often reaching 40°C or 104°F)
- Severe headache
- Pain behind the eyes
- Joint and muscle pain (often called “breakbone fever” due to its intensity)
- Nausea and vomiting
- Skin rash appearing a few days after the fever
- Mild bleeding symptoms (such as nosebleeds, gum bleeding, or easy bruising)
Warning Signs of Severe Dengue
Severe dengue, also known as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), usually develops after the fever subsides. Warning signs include:
- Severe abdominal pain
- Persistent vomiting
- Rapid breathing or difficulty breathing
- Bleeding under the skin or from the nose and gums
- Fatigue, restlessness, or irritability
- Cold or clammy skin
These signs indicate that urgent medical attention is required, as severe dengue can be fatal if left untreated.
How Dengue is Diagnosed
Diagnosis typically involves a physical examination combined with laboratory tests. Blood tests can detect the virus, antibodies, or markers of organ function that suggest complications. Because dengue symptoms resemble those of other illnesses like malaria, influenza, or Zika virus, accurate diagnosis is essential.
Treatment Options
Currently, there is no specific antiviral treatment for dengue fever. Management focuses on supportive care:
- Hydration: Preventing dehydration through oral fluids or intravenous fluids in severe cases.
- Pain relief: Paracetamol (acetaminophen) is recommended for fever and pain. Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or aspirin should be avoided, as they increase the risk of bleeding.
- Hospitalization: Necessary for patients showing warning signs or complications.
In recent years, vaccines such as Dengvaxia have been developed, but their use is limited to certain age groups and populations with prior dengue infection. Ongoing research continues to explore more effective vaccines and antiviral drugs.
Complications of Dengue Fever
While many people recover fully from dengue, complications can occur, especially in individuals who experience a second infection with a different strain of the virus.
Dengue Hemorrhagic Fever (DHF)
DHF is characterized by damage to blood vessels, leading to leakage of plasma, low platelet counts, and internal bleeding. Symptoms may include severe nosebleeds, vomiting blood, or blood in stools. DHF can rapidly progress to shock if not managed promptly.
Dengue Shock Syndrome (DSS)
DSS occurs when the circulatory system fails due to fluid leakage, leading to dangerously low blood pressure. This can cause organ failure and death if not treated urgently with intravenous fluids and supportive care.
Organ Damage
In severe cases, dengue can affect the liver, heart, or brain. Hepatitis, myocarditis (inflammation of the heart muscle), and encephalitis (brain inflammation) have been reported as rare but serious complications.
Long-Term Effects
Most people recover within two weeks, but some may experience lingering fatigue, depression, or reduced immunity for weeks after infection. Repeated infections with different dengue strains increase the risk of severe outcomes.
Who is Most at Risk?
Certain groups are more vulnerable to complications:
- Infants and young children
- Elderly individuals
- People with weakened immune systems
- Those with chronic conditions like diabetes, asthma, or heart disease
- People who have had dengue before
In endemic areas, prevention strategies and community awareness are vital to protect these groups.
Preventing Dengue Fever
Because there is no cure for dengue, prevention is the most effective approach.
Vector Control
- Eliminate standing water in containers, tires, or flower pots where mosquitoes breed.
- Use mosquito nets, screens, and repellents.
- Wear long-sleeved clothing in high-risk areas.
Public Health Measures
- Government-led fogging or spraying in outbreak zones.
- Community clean-up campaigns.
- Awareness programs to encourage early medical consultation.
Vaccination
For populations with high dengue transmission, vaccines can be part of a broader prevention strategy, though careful screening is required to ensure safe administration.
Dengue in a Global Context
Dengue is no longer just a tropical disease; climate change, urbanization, and increased travel have expanded its reach. Countries in Asia, Latin America, and Africa continue to face seasonal outbreaks, but cases are also rising in Europe and North America. This highlights the importance of international cooperation in surveillance, prevention, and research.
Living With Awareness and Caution
Dengue fever is a preventable and manageable illness when detected early. While mild cases often resolve with supportive care, the risk of complications underscores the importance of awareness, timely diagnosis, and medical supervision. Communities can play a key role in prevention by controlling mosquito breeding and seeking care at the first signs of illness. With informed action, the burden of dengue and its complications can be significantly reduced.