Dengue Fever: Symptoms, Causes, Types, and Prevention Tips

Dengue fever is a serious mosquito-borne viral illness that affects millions of people worldwide, particularly in tropical and subtropical regions. It can cause a wide range of symptoms, from mild fever to life-threatening complications. In this article, we will explore the causes, symptoms, types, and prevention tips for dengue fever, to help you stay informed and protect yourself.

What is Dengue Fever?

Dengue fever is a viral infection transmitted by the bite of an infected Aedes mosquito, primarily Aedes aegypti and Aedes albopictus. There are four distinct dengue viruses (DENV-1, DENV-2, DENV-3, and DENV-4) that can cause the disease. These mosquitoes thrive in warm, humid environments and are commonly found in many parts of India and other tropical and subtropical countries.

Symptoms of Dengue Fever

The symptoms of dengue fever usually appear 4 to 10 days after being bitten by an infected mosquito and can last up to 10 days. Some common symptoms include:

• High fever (often reaching 40°C or 104°F)
• Severe headache, especially behind the eyes
• Muscle, joint, or bone pain
• Nausea and vomiting
• Rash
• Fatigue and weakness
• Swollen lymph nodes

Symptoms of Severe Dengue (Dengue Hemorrhagic Fever)

Severe dengue, or dengue hemorrhagic fever (DHF), is a life-threatening complication that can occur after the initial symptoms of dengue fever have resolved. Warning signs of severe dengue include:

• Severe abdominal pain and tenderness
• Persistent vomiting
• Bleeding from the nose, gums, or under the skin (appearing as bruises)
• Vomiting blood or passing blood in the stools or urine
• Difficulty breathing or rapid breathing
• Feeling tired, restless, or irritable
• Confusion and irritability

Severe dengue is characterised by damage to blood vessels, a decrease in platelet count, and plasma leakage, which can lead to shock, internal bleeding, and organ failure. If you or someone you know experiences any of these symptoms, seek immediate medical attention.

Causes of Dengue Fever

Dengue fever is caused by a viral infection that is transmitted through the bites of infected mosquitoes. The primary vectors responsible for spreading the virus are female mosquitoes of the Aedes genus, particularly Aedes aegypti and occasionally Aedes albopictus. The dengue virus belongs to the Flavivirus genus of the Flaviviridae family and consists of four related viruses: dengue virus 1, 2, 3, and 4. These viruses are commonly found in tropical and subtropical regions worldwide, including Central and South America, Africa, parts of Asia, and the Pacific Islands. Although rare, the virus can also be transmitted from a pregnant woman to her baby or through blood transfusion or organ transplantation.

Types of Dengue Fever

Dengue fever can manifest in various forms, ranging from mild to severe. The main types of dengue fever include:

• Classic Dengue: Characterised by the acute onset of high fever, headaches, nausea, vomiting, and severe body aches. Symptoms typically last 2-7 days and are not considered severe.
• Dengue Haemorrhagic Fever (DHF): A severe form involving haemorrhages, particularly in the gastrointestinal tract, skin, and brain. It can lead to hypovolemic shock and is more common in children under 15 years.
• Dengue Shock Syndrome (DSS): The most severe form, characterised by circulatory collapse and rapid deterioration of one or more organs, which can be fatal if not treated promptly.

Dengue Prevention: How to Protect Yourself

Protecting yourself from dengue fever is crucial, and there are several effective measures you can take to minimise your risk of infection. These include:

• Using mosquito repellents containing DEET, Picaridin, or IR3535 on your skin and clothing
• Wearing protective clothing such as long-sleeved shirts, long trousers, socks, and shoes when outdoors
• Staying in well-screened or air-conditioned areas and using mosquito nets if sleeping areas are not adequately protected
• Eliminating mosquito breeding sites by regularly emptying and cleaning containers that hold standing water
• Using mosquito nets and screens, especially if sleeping during the day, and ensuring windows and doors have secure screens

Precautions to Take During Dengue Season

During dengue season, when the risk of infection is higher, it is crucial to take extra precautions to protect yourself and your loved ones. Some key precautions include:

• Enhancing indoor mosquito control measures, such as using repellents and insecticides, as mosquitoes that carry dengue viruses are often found indoors
• Engaging in community-level vector surveillance and control activities to reduce mosquito populations
• Avoiding areas with standing water, especially during peak mosquito activity times like dawn and dusk
• Using mosquito coils and vapourisers in addition to other preventive measures
• Protecting others in your household by taking extra measures to prevent mosquito bites, especially if someone in your home is already infected

Risk factors of Dengue Fever

Several factors can increase your risk of contracting and developing severe dengue fever. These include:

• Having a previous infection with the dengue virus (DENV) increases the risk of developing severe dengue
• Living in areas with unplanned urbanisation, high population density, and increased human mobility contribute to higher transmission rates
• Being exposed to environmental factors such as unreliable water sources, poor water storage practices, and the presence of standing water
• Maternal transmission, where pregnant women infected with dengue can pass the virus to their babies, leading to complications
• Rare cases of transmission via blood products, organ donation, and transfusions

Complications of Dengue Fever

Dengue fever can lead to severe and potentially life-threatening complications, especially in individuals who have been infected multiple times. Some key complications include:

• DHF: Characterised by severe abdominal pain, persistent vomiting, and multiple haemorrhages, particularly in the gastrointestinal tract, skin, and brain, which can lead to hypovolemic shock, especially in children under 15 years.
• DSS: Involves circulatory collapse, extreme tachycardia, pallor, and multiple organ failure, which can be lethal if not treated promptly.
• Internal Bleeding: The virus can destroy blood components that form clots and give structure to blood vessels, leading to internal bleeding.
• Organ Failure: Severe dengue can cause rapid deterioration of one or more organs, including the liver, kidneys, and heart.

When To See a Doctor

If you suspect you have dengue fever, it is essential to consult a doctor promptly, especially if you experience severe abdominal pain or tenderness, persistent vomiting, bleeding from the nose, gums, or stool, vomiting blood, cold and clammy skin, a weak and rapid pulse, a significant drop in blood pressure, or signs of circulatory failure or multiple organ failure. Early medical intervention is vital to manage symptoms and prevent severe complications effectively.

In conclusion, dengue fever is a serious viral disease transmitted by infected mosquitoes, with the potential for severe and life-threatening complications. Understanding the symptoms, causes, and types of dengue fever is crucial for early diagnosis and effective management. Preventive measures such as avoiding mosquito bites, using repellents, and implementing vector control are essential in reducing the risk of infection. By being informed and taking proactive steps, individuals can significantly reduce their risk of contracting dengue fever and its associated complications.

Frequently Asked Questions (FAQs)

References

• https://www.ncbi.nlm.nih.gov/books/NBK430732/
• https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue
• https://pmc.ncbi.nlm.nih.gov/articles/PMC4784057/
• https://www.cdc.gov/dengue/index.html
• https://www.ecdc.europa.eu/en/dengue-fever/facts