Dengue Fever: Symptoms, Diagnosis, Treatment and Prevention

By Dr. Rajiv Dang in Internal Medicine

Aug 01 , 2023 | 5 min read


Dengue fever (Break-Bone disease) is a viral disease transmitted by infected Aedes mosquitoes (Ae. aegypti or Ae. albopictus), poses a significant public health challenge worldwide.

Symptoms of Dengue

Common symptoms are:

  • Fever of 101-105°F (38.3-40.6°C) for about 2 to 7 days.
  • Severe headaches
  • Joint and muscle pain
  • Fatigue
  • Skin rash
  • Pain behind the eyes
  • Drop in Platelet Count
Stage of Dengue Platelet Count
Normal 150,000 - 450,000 per microliter (µL)
Mild Dengue Usually normal or slightly decreased
Severe Dengue Below 100,000 per µL
Severe Dengue (Danger Warning) Below 50,000 per µL
Severe Dengue (Emergency Warning) Below 20,000 per µL

The majority of dengue infections result in mild illness, though it can progress to Dengue Hemorrhagic Fever (DHF) or Dengue Shock Syndrome (DSS) in some cases.

Transmission of Dengue

  • Dengue virus is primarily transmitted through the bite of infected Aedes mosquitoes.
  • This mosquito bites during day time and on the lower parts of the body as it can't fly high.
  • These mosquitoes become carriers when they bite a person with the virus and subsequently spread it to others through bites. 
  • Preventing mosquito bites is crucial in controlling the disease's transmission.

Diagnosis of Dengue

Diagnosing dengue involves clinical presentation, history of travel and specific laboratory tests.

Diagnosing dengue involves conducting specific blood tests, including:

  • Molecular tests (RT-PCR), during the first 7 days of illness.
  • Serologic tests(IgM antibody testing) after the first 7 days.

During the first week after fever onset, patients should undergo diagnostic testing for dengue virus (RT-PCR) and IgM. For patients presenting more than one week after fever onset, IgM detection is the most useful diagnostic test.

Severe Dengue

Severe dengue, also called dengue hemorrhagic fever or dengue shock syndrome, can be life-threatening. About 1 in 20 individuals with dengue may progress to this critical stage, with a higher risk for those with prior dengue infection, infants, and pregnant women.

Warning Signs of Severe Dengue

If you or a family member experience any of the following symptoms, seek immediate medical attention:

  • High temperature
  • Severe abdominal pain or tenderness
  • Persistent vomiting (at least 3 times in 24 hours)
  • Bleeding (nose, gums, or other mucous membranes)
  • Restlessness
  • Breathing difficulty
  • Swelling in face
  • Cold or clammy skin
  • Change in mental status (e.g., confusion or altered mental status)

Treatment of Dengue

Management is focused on alleviating symptoms and providing supportive care. If you suspect dengue, follow these steps:

  • Rest as much as possible to aid recovery.
  • Use acetaminophen (paracetamol) to control fever and relieve pain. Avoid aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) due to their anticoagulant properties.
  • Stay well-hydrated by drinking fluids like water or electrolyte solutions.
  • Mild cases can be managed well at home.

Severe Dengue: Cases requiring admission

  • Frequent monitoring in an intensive care unit may be required.
  • Fluid balance is critical
  • Prophylactic platelet transfusions are not beneficial
  • Corticosteroids are generally not recommended, except in specific cases like autoimmune-related complications.

Monitoring during the febrile phase and critical phase:

  • Watch for signs of dehydration, especially if there is decreased urine output, dry mouth, sunken eyes, and listlessness.
  • Monitoring platelet count and hematocrit

Prevention of Dengue

Effective prevention strategies are essential to combat dengue. Follow these measures to protect yourself and your community:

  • Protect Yourself from Mosquito Bites.
  • Use EPA-registered insect repellents containing DEET, Picaridin, IR3535, Oil of lemon eucalyptus (OLE), or Para-menthane-diol (PMD).
  • Wear clothing that covers your arms and legs to minimise skin exposure.
  • Use mosquito nets to cover strollers and baby carriers for infants and young children.
  • Treat clothing and gear with 0.5% permethrin to repel mosquitoes effectively.
  • Install screens on windows and doors, and repair any tears or holes.
  • Prevent Dengue Spread Inside Your House
  • Ensure that those with fever rest and sleep under a bed net or use insect repellent.
  • Eliminate stagnant water in and around your home to disrupt mosquito breeding sites.
  • Install screens on windows to prevent mosquitoes from entering.

Dengue fever is a significant health concern, especially in regions with active mosquito populations. Stay vigilant, protect yourself from mosquito bites, and seek medical attention if symptoms arise. Together, we can make strides in reducing the burden of dengue.

Frequently Asked Questions

1. What are the 3 stages of dengue fever?
The stages of dengue fever are:

  • Febrile Phase: High fever, severe headache, joint and muscle pain, rash
  • Critical Phase: Potential severe symptoms, bleeding, low platelet count, circulatory failure (dengue hemorrhagic fever or dengue shock syndrome)
  • Recovery Phase: Gradual improvement, subsiding of symptoms, possible fatigue and weakness

2. Is dengue serious?
Yes, dengue fever can be serious. While many cases of dengue fever are mild and can be managed with supportive care, some individuals can develop severe forms of the disease.

3. What happens on the 7th -9th days of dengue?
On the seventh day of dengue fever, fever and other symptoms like headache, joint pain, and rash may continue or start to improve. It's important to monitor your condition and seek medical help if needed.

4. How many days does dengue last?
Dengue fever can last anywhere from a few days to about a week or more.

5. What is the best treatment for dengue?
The best treatment for dengue involves:

  • Staying hydrated with fluids.
  • Managing pain and fever with paracetamol.
  • Getting plenty of rest.
  • Monitoring symptoms closely.
  • Seeking medical care for severe cases.
  • Avoid NSAIDs and aspirin, and prevent mosquito bites.

6. What food is good for dengue patients?

For a dengue patients following food options are good:

  • Stay hydrated with water, coconut water, and clear soups.
  • Eat soft fruits like bananas, papayas, and pomegranates.
  • Opt for lean proteins like chicken, fish, and tofu.
  • Choose easily digestible whole grains like rice.
  • Include yoghurt and other low-fat dairy.
  • Avoid spicy, greasy, and heavy foods.
  • Eat small, frequent meals.
  • Consume vitamin C-rich foods like citrus fruits.
  • Consult a healthcare professional for guidance.

7. When do platelets fall in dengue?
In dengue fever, platelet levels can start to fall during the critical phase of the illness, which is typically around the time when the fever should be subsiding. This drop in platelet count usually occurs between the third and seventh days of the illness. 

8. On which day is dengue positive?
For most cases of dengue fever, the virus can usually be detected in the blood within the first few days of symptom onset, during the febrile phase. This typically means that the virus can be detected within the first 5-7 days after the onset of symptoms.

9. Which day is most critical in dengue?
The most critical phase in dengue fever is typically around the time when the fever should be subsiding, usually between the third and seventh day after symptom onset. During this phase, some individuals may experience a sudden and rapid deterioration of their condition, which can lead to complications, such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS).

10. Who is at risk for dengue?
People at risk for dengue include those in tropical regions, previous dengue patients, young and older individuals, weakened immune systems, outdoor exposure, poor living conditions, and travellers to endemic areas.

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