Understanding Dengue Fever: A Complete Guide

Do you have what seems to be flu-like symptoms: Fever, rash along with a few itchy mosquito bites? You might be dealing with dengue fever. It is a serious illness that needs prompt medical attention for a positive treatment outcome. But don’t worry! This blog will guide you through everything you need to know about dengue fever, from its causes and symptoms to treatment options and prevention strategies.

What is Dengue Fever?

Dengue fever is a mosquito-borne viral infection found in tropical and subtropical areas. It often causes flu-like symptoms like fever, rash, and muscle aches, but most cases are mild and resolve on their own. However, a serious form called dengue haemorrhagic fever can lead to bleeding, low blood pressure, and even death. There's no specific treatment for dengue, but early detection and proper hydration can make a big difference.

What are the Phases of Dengue Fever?

Dengue fever progresses through three distinct phases:

• Febrile Phase (lasts 2-7 days): This is the initial phase marked by a sudden onset of high fever, reaching up to 104°F. Other symptoms include severe headache, muscle and joint pain, nausea, vomiting, and fatigue.
• Critical Phase (lasts 24-48 hours): This is the most crucial phase, typically occurring around days 3-7. The fever might subside or fluctuate, but it's during this time that complications like plasma leakage and internal bleeding can develop in severe cases.
• Recovery Phase (lasts several weeks): If someone doesn't experience complications in the critical phase, they enter recovery. Symptoms gradually improve, fever breaks, and blood counts return to normal. This phase can take several weeks as the body regains its strength.

How does Dengue Spread?

Dengue fever follows a cycle that hinges on the interaction between infected mosquitoes and humans. Here's a breakdown of how it spreads:

• The Infected Mosquito: The culprit behind the spread is a bite from a female Aedes dengue fever mosquito, most commonly Aedes aegypti or Aedes albopictus. These mosquitoes thrive in tropical and subtropical climates and are known to bite during the daytime, especially in the morning and afternoon hours.
• Transmission from Human to Mosquito: When an infected Aedes mosquito bites a person carrying the dengue virus in their bloodstream, the virus enters the mosquito. Over the next 8-12 days, the virus replicates within the mosquito's body. This replication process specifically targets the mosquito's midgut and salivary glands.
• Transmission from Mosquito to Human: After this incubation stage of dengue fever cycle, the infected mosquito becomes capable of transmitting the virus to another person through a subsequent bite. The virus concentrates in the mosquito's saliva, and when it bites another human, the virus is injected along with the saliva. This creates a cycle where the virus is passed back and forth between humans and mosquitoes.

What Causes Dengue Fever?

Dengue fever is caused by any one of five closely related viruses belonging to the Flavivirus genus. These viruses are:

• Dengue virus type 1 (DENV-1)
• Dengue virus type 2 (DENV-2)
• Dengue virus type 3 (DENV-3)
• Dengue virus type 4 (DENV-4)
• Dengue virus type 5 (DENV-5)

Once the virus enters a human's bloodstream, it infects white blood cells and other immune system cells. The body's immune response to the virus is what causes the symptoms of dengue fever. In some cases, this immune response can become overly aggressive, leading to the more serious dengue haemorrhagic fever.

Having a previous dengue infection with one serotype (virus type) can increase your risk of developing severe dengue if infected with a different serotype later. This is because antibodies developed during the first infection can interact with the second virus in a way that worsens the immune response.

What are the Symptoms and Signs of Dengue Fever?

Dengue fever presents a range of signs and symptoms, which can vary from mild to severe. Here's a detailed overview:

Mild Dengue Fever

• High Fever: Sudden onset of high fever, often reaching up to 104°F (40°C).
• Severe Headache: Intense pain, particularly around the forehead.
• Pain Behind the Eyes: Often described as a deep, throbbing pain.
• Joint and Muscle Pain: Severe pain, earning dengue the nickname "breakbone fever".
• Nausea and Vomiting: Gastrointestinal symptoms, including nausea, vomiting, and loss of appetite.
• Fatigue: Extreme tiredness and general weakness.
• Skin Rash: Rash that can appear a few days after the fever starts, often beginning on the chest and spreading to other parts of the body.
• Mild Bleeding: Symptoms such as nosebleeds, gum bleeding, or easy bruising.

Severe Dengue (Dengue Haemorrhagic Fever and Dengue Shock Syndrome)

• Severe Abdominal Pain: Abdominal pain is intense and persistent pain in the stomach area.
• Persistent Vomiting: Frequent vomiting, which may be accompanied by blood.
• Rapid Breathing: Fast and laboured breathing, often associated with fluid accumulation in the chest.
• Bleeding: Severe bleeding from the nose, gums, or under the skin, which may appear as bruises or spots.
• Plasma Leakage: Leakage of plasma from blood vessels, leading to a decrease in blood volume.
• Restlessness and Irritability: Changes in behaviour, often indicating shock.
• Signs of Shock: Signs and symptoms of dengue fever such as cold or clammy skin, rapid pulse, and low blood pressure, which can lead to dengue shock syndrome (DSS) and can be life-threatening without immediate medical attention.

Read More- Dengue Haemorrhagic Fever: Symptoms, Treatment, and Prevention

What are the Risk Factors for Dengue Fever?

Here's a breakdown of the key risk factors for dengue fever:

Living in or Travelling to High-Risk Areas

Dengue fever is most prevalent in tropical and subtropical regions around the world, including Southeast Asia, the Western Pacific islands, Latin America, and Africa.

If you're travelling to or living in an area with known dengue activity, your risk of exposure to the virus through infected mosquitoes is significantly higher.

Previous Dengue Infection

Having had dengue fever in the past can actually increase your risk of developing a more severe form of the illness if infected with a different dengue virus type later. This is because your immune system has antibodies from the first infection, which can interact with the second virus in a way that intensifies the immune response, potentially leading to dengue haemorrhagic fever.

Age

While anyone can contract dengue fever, young children and adults are more susceptible to experiencing severe complications.

Underlying Health Conditions

Certain underlying health conditions, such as diabetes, obesity, and chronic illnesses, can put individuals at a higher risk of developing severe dengue.

Limited Access to Quality Healthcare

In areas with limited access to proper medical care and diagnostic tools, early detection and effective management of dengue fever become more challenging, potentially increasing the risk of complications.

Environmental Factors

Unplanned urbanisation creates ideal breeding grounds for Aedes mosquitoes, the primary transmitters of dengue. Factors like stagnant water in containers, discarded tires, and clogged gutters can contribute to increased mosquito populations and a higher risk of transmission.

Diagnosing Dengue Fever

Dengue fever, with its flu-like symptoms and potential for serious complications, can be a cause for concern. Fortunately, various diagnostic tests can help dengue fever doctors detect the presence and type of dengue virus causing the illness. These tests fall into two main categories: virological and serological.

Virological Tests

Virological tests aim to detect the actual dengue virus itself or its genetic material. These tests are most effective during the early stages of infection, typically within the first few days of symptom onset. Here are two common virological tests used for dengue diagnosis:

• Viral RNA Detection (RT-PCR): This highly sensitive test identifies the presence of dengue virus ribonucleic acid (RNA), the genetic material of the virus. A blood sample is collected, and the RNA is extracted and amplified, allowing for detection of even small amounts of the virus.
• Virus Isolation: This test involves attempting to grow the dengue virus in a laboratory setting using cell cultures. If the virus is present in the blood sample, it will multiply within the cell culture, confirming the diagnosis. While this test can be definitive, it takes longer to produce results compared to RT-PCR.

Serological Tests

Serological tests, unlike virological tests, don't directly detect the virus itself. Instead, they analyse the body's immune response to the dengue virus infection. These tests can be helpful at different stages of the illness and provide valuable information about past exposure as well. Here are two common serological tests used for dengue diagnosis:

• IgM Antibody Capture ELISA: This test identifies the presence of IgM antibodies, which are the body's initial immune response to a new infection. A positive IgM test result typically indicates a recent dengue infection, within the first few days to a couple of weeks. However, a positive result can also occur in cases of other flavivirus infections.
• IgG Antibody ELISA: This test detects the presence of IgG antibodies, which develop later in the infection and can persist for years after recovery. An IgG test alone can't definitively diagnose a current dengue infection. However, a rising IgG level in paired blood samples collected a few weeks apart can indicate a recent dengue infection. Additionally, the presence of IgG antibodies can suggest a past dengue infection.

Choosing the Right Test

The selection of the most appropriate diagnostic test depends on several factors, including the stage of illness, the patient's symptoms, and the healthcare provider's judgement. Early in the infection, virological tests like RT-PCR might be preferred for their accuracy in detecting the virus. Later, serological tests like IgM ELISA can be helpful to confirm a recent dengue infection.

Treatment of Dengue Fever

Dengue fever, while a potentially serious illness, doesn't have a specific antiviral medication or cure. However, various dengue virus treatment strategies can significantly improve the outcome and prevent complications. Here's a deeper dive into how healthcare professionals manage dengue fever:

Supportive Care

Since there's no specific cure for dengue, the primary focus of treatment revolves around supportive care to alleviate symptoms and prevent complications. Here's a breakdown of the key elements:

• Rest: Getting plenty of rest allows your body to focus its energy on fighting the dengue virus. This may seem like common sense, but during a feverish illness, it's easy to underestimate its importance.
• Fluid Management: Maintaining adequate hydration is crucial, especially if vomiting is a concern. Dehydration can worsen symptoms and potentially lead to complications. Healthcare providers will assess individual needs and may recommend oral rehydration solutions or administer intravenous (IV) fluids in severe cases.
• Pain Management: Dengue fever medication like paracetamol can help manage fever and muscle aches, which are hallmarks of the disease. It's important to avoid aspirin and ibuprofen, as these medications can increase the risk of bleeding, a potential complication of dengue haemorrhagic fever.

Electrolyte Replacement

Dengue fever can lead to electrolyte imbalances due to vomiting and diarrhoea. Electrolytes are minerals in the blood that play a crucial role in various bodily functions, including muscle and nerve function. Replacing electrolytes through oral rehydration solutions or intravenous fluids helps maintain vital bodily functions and prevent complications.

Blood Transfusions 

In severe cases of dengue haemorrhagic fever with significant blood loss, blood transfusions might be necessary. This procedure replaces lost blood and helps maintain blood pressure, which can be critically low in DHF.

Monitoring Vital Signs

Close monitoring of vital signs like temperature, blood pressure, and haematocrit (red blood cell count) is essential throughout the illness. This vigilance helps healthcare providers detect early signs of complications like dengue haemorrhagic fever (DHF). A sudden drop in haematocrit, for example, could indicate plasma leakage, a hallmark of DHF.

How to Prevent Dengue Fever?

Here's a breakdown of key strategies to shield yourself from this tropical menace:

Guarding Yourself from Mosquito Bites

Mosquitoes, particularly Aedes aegypti and Aedes albopictus, are the primary culprits behind dengue transmission. Here's how to create a defensive barrier against their bites:

• Repellents: Apply mosquito repellents containing DEET, picaridin, IR3535, or oil of lemon eucalyptus to exposed skin. Reapply at recommended intervals, especially after sweating or swimming.
• Clothing Choices: Wear loose-fitting, long-sleeved shirts and pants, especially during peak mosquito biting times (dawn and dusk). Opt for light-coloured clothing, as mosquitoes are more attracted to darker colours.

Eliminate Mosquito Breeding Grounds

Since stagnant water is a breeding haven for Aedes mosquitoes, focus on eliminating potential mosquito breeding sites around your home and community:

• Empty Containers: Regularly discard or empty any containers that can hold water, such as flower pots, saucers, old tires, buckets, or even bottle caps.
• Change Water Regularly: If you have containers that must hold water, like water storage tanks or birdbaths, change the water at least once a week to prevent mosquito larvae from developing.
• Proper Drainage: Ensure proper drainage around your home to prevent water from accumulating in clogged gutters or low-lying areas.

Utilise Physical Barriers

While not foolproof, physical barriers can offer an additional layer of protection against mosquito bites:

• Window and Door Screens: Install screens on windows and doors to prevent mosquito entry into your living space. Consider using mosquito nets around beds, especially for children or during daytime naps.
• Insecticide-Treated Bed Nets: In high-risk areas, using insecticide-treated bed nets while sleeping can provide additional protection.

Community-Based Efforts

Dengue prevention is most effective with a community-wide approach. Collaborate with your neighbours to implement mosquito control measures in your community. This can involve collective efforts to clean up potential breeding grounds and raise awareness about preventive measures.

Stay Informed

If you're travelling to a dengue-prone area, stay informed about the local risk level and recommended prevention strategies. Consult a healthcare professional or travel clinic for guidance on appropriate vaccinations and other preventive measures specific to your travel destination.

Conclusion

Dengue fever, while a concern in tropical regions, is largely preventable. By understanding the transmission cycle, using effective mosquito repellents and protective clothing, and eliminating mosquito breeding grounds around your home, you can significantly reduce your risk. Early diagnosis and proper hydration are crucial if you experience any dengue symptoms. Don’t hesitate to contact Max hospitals, the best dengue fever hospital for any query.