Dengue

Overview

Dengue is a mosquito-borne viral disease. It spreads from one person to the other only when an Aedes mosquito infected with the dengue virus bites a healthy person especially during day time. It does not spread by touch, cough or secretions. Dengue presents as high-grade fever, pain in the eyes, skin rash, headache, body aches, and pain in the joints. In severe cases, it can lead to difficulty in breathing, severe abdominal pain and bleeding. Most patients with dengue fever have mild illness and can be managed at home by maintaining fluid intake, monitoring symptoms and taking medicines. However, at times, it may cause a potentially serious complication, called severe dengue (hemorrhage and shock). The disease can be prevented by ensuring proper measures to prevent mosquito breeding and water stagnation. Also, use of mosquito nets and repellents can help you to prevent mosquito bites. People suffering from dengue fever should take adequate rest, eat a healthy diet, take plenty of fluids and monitor platelet count and blood pressure closely.

Key Facts

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Symptoms

The symptoms of dengue can be confused with other common illnesses such as flu, malaria, and chikungunya. However, dengue should be suspected if you develop a sudden onset of high-grade fever (40°C/104°F) along with rash, nausea, and body aches. According to the WHO, dengue can be categorized into three phases:

  • Febrile phase
  • Critical phase
  • Recovery phase

1. Febrile phase

This phase usually lasts 2-7 days and is often accompanied by:

  • Generalized body ache
  • Eye pain (pain with eye movement)
  • Muscle pain
  • Joint pain
  • Headache
  • Loss of appetite
  • Nausea
  • Vomiting
  • Facial flushing
  • Skin rashes
  • Respiratory symptoms (cough, sore throat, congestion, etc.)

2. Critical phase

The fever usually decreases around the 3rd to 7th day of illness. This marks the beginning of the critical phase. It is followed by extreme fatigue, which can last for a few days to weeks. There could also be a rapid decrease in the platelet and leucocyte (white blood cell) count. In some cases, there can be severe organ impairment and internal bleeding.

3. Recovery phase

Post-critical phase, there is an improvement in the condition of the patient within 48-72 hours. In this phase, there is an improvement in appetite and gastrointestinal symptoms. There might be a reappearance of skin rash during the recovery phase.

Note: In younger children, these symptoms are generally mild, but older kids and adults may have moderate to severe symptoms depending on the intensity of the infection.

Signs of severe dengue

As per the CDC, about 1 in 20 people who get sick with dengue may develop a severe form of the disease. After the first sign of dengue appears, it may take around 3-7 days for the disease to turn into a severe condition. This is the critical phase, which can even lead to a drop in temperature, indicating that special care is needed rather than recovery. The warning signs that indicate severe dengue are:

  • Severe abdominal pain
  • Rash all over the body
  • Bleeding gums
  • Blood in vomit
  • Rapid heart rate
  • Low blood pressure
  • Difficulty in breathing
  • Fatigue/restlessness
  • Severe bleeding

In case you suffer from any of these symptoms, it is advised to immediately get admitted to a hospital and follow your doctor’s suggestions without fail.

Cause

Dengue is a viral infection caused by the bite of a female Aedes aegypti mosquito. The virus responsible for dengue is known as dengue virus (DENV), which belongs to the Flaviviridae family. There are four distinct types of dengue virus: DENV-1, DENV-2, DENV-3, and DENV-4.

When a mosquito infected with the dengue virus bites a healthy person, the virus spreads into the bloodstream, resulting in infection. The mosquito responsible for dengue can be identified by its characteristic black and white markings. It breeds in stagnant water and is most active during the early hours of the day. Infection with any one of the serotypes provides lifelong immunity to that specific strain.

RiskFactors

You may be at a high risk of suffering from dengue if:

  • There are several cases of dengue in your locality.
  • Your area has pooled water or if you work in construction sites, as the risk of breeding mosquitoes is high in such areas.
  • You travel to places where the prevalence of dengue is high.

Diagnosis

If a person is experiencing high fever, nausea, rash, and body ache, it is advisable to get a blood test done. In most cases, a complete blood count (including a platelet count) is recommended if your doctor suspects dengue. However, it is a nonspecific test because it does not confirm the presence of the dengue virus or detect the type of virus.

To detect the presence of the dengue virus in the blood, definitive tests are required, which include:

  • Dengue antigen test: Also known as the dengue NS1 antigen test, this blood test helps to detect the dengue virus early in the course of an infection. It should be done within the first five days of symptom onset, as the chances of false positive and negative results increase after 5 to 7 days. Book Test Here
  • Dengue antibody IgM test: This test looks for IgM antibodies in the blood, which appear during the early course of the disease (acute infection). It can also help differentiate between primary (first-time infection) and secondary (subsequent infection with other serotypes) infections. Book Test Here
  • Dengue antibody IgG test: This test is used to detect infection in the later stages of the disease, as the level of IgG in the blood increases slowly. Typically, the level rises 6 to 10 days after infection, and the antibodies can remain in the blood for around 90 days or for life. Book Test Here
  • Dengue RNA PCR test: This is a primary test used to detect the dengue virus in the early course of the infection. A positive result not only confirms the infection but also helps identify the different serotypes of the dengue virus. The test is approximately 90% sensitive and 95% specific. Book Test Here

Prevention

The best way to prevent dengue is to prevent mosquitoes in your immediate surroundings. To achieve this, you need to:

  • Prevent water stagnation: Look around the house and eliminate any sources of water stagnation, as mosquitoes breed in stagnant water. Drain buckets after bathing or washing, ensuring that mugs and buckets remain dry. Fix leaking taps in the bathroom and kitchen to keep the area dry and prevent water collection in containers. Drain water from coolers and keep them dry. Avoid overwatering potted plants to prevent water stagnation in the soil.
  • Use mosquito nets: Utilize mosquito nets at night to avoid mosquito bites. They can also be used during the day for babies and the elderly who may nap in the afternoon. Ensure to cover and close any holes in windows and doors to block mosquito entry. Wire mesh screens can be installed on windows to keep mosquitoes out.
  • Apply mosquito repellents: Use mosquito repellent cream, especially for children who play outdoors. Mosquito repellent liquidators are also widely available for use in homes. In addition to commercial repellents, there are natural methods to deter mosquitoes, such as burning camphor, lighting lavender candles, using citronella or eucalyptus essential oils, and keeping a potted tulsi plant near windows.
  • Cover up: Wear full-sleeved clothing and full-length pants as much as possible to cover most areas of your body. Special care should be taken to ensure that children are adequately covered.

Treatment

There is no specific treatment for dengue. The treatment is aimed at relieving the symptoms. Most patients with dengue fever have mild illness and can be treated at home by following strict dietary guidelines and a course of medication. In cases of severe dengue, where the platelet count drops significantly (a condition known as thrombocytopenia), platelet transfusion is advised.

1. Take Sufficient Rest

As dengue causes severe fatigue and high fever, ensure you rest as much as possible to give your body sufficient time to recover.

2. Bring Down Your Fever

Antipyretic drugs like paracetamol can help reduce temperature and relieve body aches. Avoid drugs such as aspirin and other painkillers as they may increase the risk of bleeding or hemorrhage. Antibiotics are generally not required. Sponging the person with cool water can also help reduce fever.

3. Stay Hydrated

Dehydration is a common complication of dengue due to water loss from fever, vomiting, and inadequate fluid intake. To prevent dehydration, ensure you stay hydrated by drinking fluids such as coconut water, buttermilk, fruit juices, lemon water, milk, and electrolyte drinks along with water. If you experience signs of severe dehydration, consult a doctor immediately to prevent complications.

4. Monitor Your Condition

The period after the fever starts to subside is critical. Some individuals may develop warning signs such as vomiting (at least three times in 24 hours), difficulty in breathing, bleeding from the nose or gums, and blood in vomit or stool within a day or two after the fever decreases. This occurs in approximately 1 in 20 people with dengue and may require hospitalization as it could be life-threatening. Be vigilant and monitor for warning signs. Severe dengue is a medical emergency and requires immediate medical care at a hospital.

5. Try Home Remedies

Several home remedies are popular for treating dengue fever, as they are believed to increase platelet count:

  • Papaya Leaves: According to research (Subenthiran S, et al), the juice of papaya leaves is known to inhibit the growth of the dengue virus and increase platelet count.
  • Giloy: Packed with anti-inflammatory and antipyretic properties, giloy juice aids in managing dengue fever. It not only increases platelet count but also boosts immunity, aiding in quick recovery.
  • Kiwi: Many believe that eating kiwi fruit daily improves platelet count. However, there is no research to prove its efficacy in increasing platelet count. The fruit is rich in Vitamin C, which acts as a potent antioxidant and boosts immunity.

Watch this video to know more about the tests, treatment, and what to eat and avoid in dengue.

Complications

Rarely, severe dengue can be complicated by organ damage and internal bleeding (dengue hemorrhagic fever). This results in a sudden drop in blood pressure, feeble pulse, hypovolemia, and eventually dengue shock syndrome.

The World Health Organization (WHO) has laid down criteria for the diagnosis of dengue hemorrhagic fever. These are:

  • Low platelet count (< 100,000)
  • Fever for 2 to 7 days
  • Hemorrhagic manifestations (internal bleeding)

In the early stages, the platelet count is usually within the normal range, but the hemoglobin level may be high. If the hemoglobin level is raised (> 14 g/dL), a doctor should be consulted even if the platelet count is normal. The platelet count begins to fall once the fever starts to subside. Even when the platelet count is falling, there is no need to panic.

REMEMBER! There is no role for platelet transfusions in a patient who has no active bleeding. Do not insist on platelet transfusion in the absence of bleeding.

Frequently asked questions

Dengue is not spread by touch, cough, or secretions but can be transmitted through mosquito bites. The virus may be present in the blood during the first week of infection, allowing mosquitoes to spread it to others.
Most dengue patients do not need hospitalization. They should rest, stay hydrated (3-4 liters), and monitor platelets. Use cold sponging and paracetamol for fever while avoiding aspirin and ibuprofen. Follow up with a doctor every 24 hours and consider home remedies like papaya and giloy.
The WHO has approved the dengue vaccine CYD-TDV (Dengvaxia) for those previously infected with one of the four dengue serotypes. It is a live attenuated tetravalent vaccine and is not recommended for those without prior infection due to potential serious complications.
Dengue should be suspected with sudden onset of high fever, severe headache, pain behind the eyes, abdominal pain, body aches, rash, and vomiting. The fever typically lasts 5-7 days.
Hospitalization is necessary if the patient is dehydrated, bleeding, or shows other danger signs. Patients are generally not admitted if platelet counts are above 50,000, but should consult a doctor if counts drop further. Platelet transfusions are given if counts fall below 10,000 without bleeding.
Yes, it is possible to get dengue more than once due to four different strains of the virus, with no immunity to other strains after infection.
Dengvaxia is not available in India due to insufficient safety and efficacy data in the population. However, India is developing its own dengue vaccine that will be available soon.
In the first week of symptoms, a dengue PCR test and NS1 antigen are recommended. From the 3rd to 9th day, a combination of NS1 antigen/PCR and IgM antibodies is advised. A complete blood count may be recommended but does not confirm the dengue virus or its type.
Yes, it's possible as white blood cells may decrease while platelets remain normal in the initial phase. Consult a doctor if you experience dengue symptoms.
A decrease in fever around days 3-7 can indicate the start of a critical phase with potential rapid platelet count drop. Monitor platelet levels and watch for danger signs like bleeding or abdominal pain.