Symptoms, Causes, and Prevention A virus that is spread by mosquitoes, dengue fever poses a serious threat to international health, especially in tropical and subtropical areas. Understanding the causes, symptoms, and preventive measures for dengue and severe dengue is critical for safeguarding public health. This blog delves into the details of both dengue and its more dangerous form, severe dengue.

What is Dengue Fever?

Dengue fever is caused by the dengue virus, which is transmitted to humans through the bite of an infected female Aedes mosquito, primarily the Aedes aegypti. This virus exists in four distinct serotypes, meaning a person can be infected up to four times in their lifetime, with different serotypes causing each infection.

Common Symptoms of Dengue

The onset of dengue is marked by a sudden high fever that typically lasts between 2 to 7 days. Other accompanying symptoms may include:

Severe headache

Pain behind the eyes

Joint and muscle pain

Nausea and vomiting

Skin rash, which may appear 2–5 days after the fever

Mild bleeding (nosebleeds, gum bleeding, or easy bruising)

What is Severe Dengue (Dengue Hemorrhagic Fever)?

Severe dengue, also known as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), is a more life-threatening complication of the dengue virus. This condition occurs when the virus damages blood vessels, causing plasma leakage, fluid accumulation, respiratory distress, severe bleeding, and organ impairment.

Symptoms of Severe Dengue

While severe dengue begins similarly to typical dengue fever, it escalates with alarming symptoms such as:

Severe abdominal pain

Persistent vomiting

Rapid breathing

Bleeding from the nose or gums

Fatigue and restlessness

Blood in vomit or stool

Shock (due to low blood pressure)

Severe dengue is most likely to occur in individuals who have had a previous dengue infection, especially if they are infected by a different serotype the second time.

Risk Factors for Severe Dengue

Certain factors increase the risk of developing severe dengue, including:

Previous infection with the dengue virus

Young children and infants

Individuals with weakened immune systems

Pregnant women

How Dengue is Transmitted

Dengue is transmitted through the bite of infected mosquitoes, specifically from the Aedes genus. The mosquito becomes a carrier when it bites an individual already infected with the dengue virus.After becoming infected, the mosquito can bite humans again and spread the virus.

The Aedes Mosquito and its Behavior

The Aedes aegypti mosquito, the primary carrier of the dengue virus, typically bites during daylight hours, with peak periods early in the morning and before dusk. These mosquitoes are known to thrive in urban environments and breed in stagnant water, making water storage practices in densely populated areas a major risk factor for dengue transmission.

Diagnosing Dengue and Severe Dengue

Diagnosis is typically confirmed through:

Blood tests: 

These detect the virus or antibodies in the blood.

Clinical symptoms of severe dengue: 

Healthcare professionals also rely on the observation of typical dengue symptoms such as fever, rash, and body aches.

Diagnostic Tools for Severe Dengue

In severe dengue, the monitoring of vital signs, blood tests to assess organ function, and other laboratory markers (such as platelet count and hematocrit levels) are used to evaluate the patient’s condition.

Treatment for Dengue and Severe Dengue

There is no specific antiviral treatment for dengue. Management primarily focuses on relieving symptoms and maintaining hydration.

Treatment for Dengue

Fluid replacement: 

Drinking plenty of fluids helps prevent dehydration.

Pain relievers: 

Acetaminophen (paracetamol) can be used to reduce fever and pain. Aspirin and NSAIDs (nonsteroidal anti-inflammatory drugs) should be avoided as they can increase the risk of bleeding.

Treatment for Severe Dengue

Severe dengue requires hospitalization and may involve:

Intravenous (IV) fluids: 

To maintain fluid balance and prevent shock.

Blood transfusions: 

In cases of significant bleeding or very low platelet counts.

Close monitoring: 

Patients need to be closely observed, especially during the critical phase when the fever subsides, as this is when severe symptoms can develop.

Preventing Dengue and Severe Dengue

Since there is no specific vaccine available for widespread use in most countries, prevention is focused on reducing mosquito exposure and breeding.

Tips for Dengue Prevention

Eliminate breeding sites: 

Remove stagnant water in containers, tires, flowerpots, and water tanks.

Use mosquito repellents: 

Apply insect repellent containing DEET, picaridin, or oil of lemon eucalyptus.

Wear protective clothing: 

Wear long sleeves and pants, particularly during peak mosquito activity.

Use mosquito nets: 

When sleeping, especially in areas without air conditioning.

Install window screens: 

To prevent mosquitoes from entering homes

Conclusion: Combating Dengue Requires Vigilance

Dengue and severe dengue pose significant public health risks, particularly in tropical and subtropical areas. Understanding how the disease spreads, recognizing early symptoms, and taking preventive actions can help reduce the incidence of dengue. Additionally, communities must work together to eliminate mosquito breeding grounds and protect vulnerable populations.

By staying informed and vigilant, we can all play a role in preventing the spread of dengue and minimizing its severe consequences.