Dengue Symptoms, Risk Factors, Diagnosis and Treatment | Narayana Health

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Symptoms, Causes, Diagnosis & Treatment



What is Dengue?

Dengue is a virus-based infection majorly predominant in the tropical regions of the world. The female Aedes mosquito is the vector that transmits dengue causing virus cells from infected people to healthy people through blood-sucking bites. The virus then transfers from the vector and enters the host to rapidly reproduce dengue causing virus. Dengue is commonly classified in 4 different serotypes, which are: DENV 1, DENV2, DENV3, and DENV4. DENV 3, and 4 are the most occurring forms of the virus. These serotypes belong to the genus Flavivirus. Outbursts of Dengue are commonly recorded in the Indian Subcontinent, south-east Asia, southern China, Taiwan, few countries in Central and South America, a few islands in the Caribbean, Mexico, and Africa.

The infestation of these disease occurring agents is commonly found near open drains, stagnant water bodies, marshy lands, and human-inhabited locations. 2007 to 2009 has witnessed major Dengue outbreaks in various parts of the world with an alarming mortality rate of 50% in a short period. Once the DENV serotype is introduced into a new host from a viremic source, the serotype attacks the Dendritic cells, Langerhans cells, and Skin-Dendritic cells. Dendritic cells of all the other cells are important as they form a direct route for the pathogen to access and affect the lymph nodes, thereby compromising the adaptive immune responses of the host. Researchers and doctors are constantly trying to create a vaccine for Dengue.



Symptoms of Dengue

The Virus cells after entering the host, multiply and take 2-12 days before any dengue symptoms start appearing in the host. Depending on the type of serotype, the symptoms and severity of the condition persist.

The symptoms include:

  • Sudden fever
  • High temperature
  • Eye pain
  • Nausea
  • Vomiting
  • Bleeding
  • Teeth pain
  • Nose bleed
  • Skin rash



Types of Dengue

About 40% of the population of the 100 countries where Dengue is endemic are susceptible to Dengue. If the diagnosis is made in the early stages, the chances of early recovery are high. Depending on the severity and the symptoms observed in the host, Dengue is classified into:

  • Mild Dengue Fever
  • Dengue Haemorrhagic fever
  • Dengue Shock Syndrome

Mild Dengue Fever:

It takes up to 7 days for the symptoms of Mild Dengue Fever (MDF) to appear on the host. These symptoms include muscle aches, joint pains, Vomiting, High fever, intense and prolonged headaches. Dengue in this stage when diagnosed early can be intervened with different options depending on the severity of the condition.

Dengue Haemorrhagic fever:

Dengue Haemorrhagic fever (DHF) is a serious condition or form of Dengue, when left untreated or when improper medication is taken, this form of Dengue can be fatal. The symptoms of DHF are often seen during or after recovering from MDF. DHF often occurs when blood transfusion occurs through a mosquito from a viremic person. The symptoms of DHF include but are not limited to the ones presented by a person infected with MDF.

The symptoms are internal bleeding, sudden fever, cold chills, cold or clammy skin, bleeding and bruising under the skin, nose bleeds, restlessness, and a significant decrease in blood pressure.

Dengue Shock Syndrome:

Dengue Shock Syndrome (DSS) is generally the next condition that patients experiencing DHF transition into. In this, the patient experiences a sudden onset of shock, high fever, and is prone to sudden collapse due to a significant drop in blood pressure. In this type of Dengue, the patient showcases severe headache, sore throat, and respiratory irregularities.

DSS is majorly seen in children under 10 years of age. The mortality rate of DSS is currently between 6-30%. This is a severe form of Dengue where the symptoms include Blood in stool, blood in vomit, weak pulse, and spitting up blood.



Causes of Dengue

Causes of Dengue

Viremic transfer of Dengue causing virus from a person infected with Dengue to a healthy host through mosquito bites is a major cause of Dengue. In this, when a mosquito bites an infected person, the virus enters the mosquito through the bloodstream and is later released into the host when the same mosquito bites another person.

While there are preventive vaccines available for Dengue, a person suffering from Dengue generally becomes immune to that strain of serotype. However, when a person is infected with Dengue for the second time, they are more prone to being infected with DSS or DHF.

Dengue commonly occurs in human-inhabited areas and these disease-causing vectors rapidly breed in stagnant waters like open drains, water-filled disposed tyres, unattended flower vases, open tanks, and other stagnant water sources.

Sometimes, Dengue is also transmitted intravenously and through sex. However, the reported issues for these forms are minute.



Steps to prevent Dengue

The global medical community is actively researching for isolating and coming up with vaccinations that could make a person immune to Dengue. As of now, there are no vaccines available to completely prevent the occurrence of Dengue. Dengue at its core is a disease that is predominantly caused by the Aedes mosquito and measures to prevent such an occurrence can go a long way in preventing a Dengue attack.

The tropical countries are infamous for Dengue and it is often advised to be prepared to protect your body from mosquito bites. You can be successful in Dengue fever prevention by following these steps.

1)  Cover your body from top to toe:

Cover your body with long pants and long-sleeved t-shirts when visiting mosquito-infested areas. Use protective clothing like gloves, socks, and hats to leave no area of your skin exposed. It is also recommended to tuck your t-shirt ending near your sleeve into the gloves and the pants in your socks near the ankle to leave no openings for a mosquito to reach exposed skin.

2)  Use mosquito repellants:


Using a mosquito repellant with at least 10% of N-Diethyl-Meta-Toluamide is recommended for direct skin. This will keep mosquitos away. This formula is commonly formed in brands like Odomos, Good Knight, and Mamaearth natural.

If you are camping or are in a mosquito-infested area, it is advised that you spray permethrin on your clothes, tent, and other accessories. Permethrin is a substance that kills any mosquito that comes in direct contact with the substance. Sometimes, trekkers are advised to buy gear (clothes) that are lined with Permethrin to reduce any chance of Dengue.

3)  Install a door/window screen:

Door or window screens are specially crafted in ways that allow free flow of air and sunlight but prevent other tiny insects from coming into the house. Installing screens on doors, windows, and other inlets can go a long way in preventing Dengue.

4)  Things you can do at home:

The male Aedes mosquito often breeds in still standing stagnant waters. Ensuring that there is no water stagnating in flower pots, tyres, buckets, old utensils, Air-conditioning water exhausts, open buckets, and leaky pipes can prevent this. While camping, it also advised to stay away from areas like ponds, and lakes as these water bodies can be a breeding ground for disease-causing mosquitoes.

5)  Use contraceptives

Very rarely, Dengue is transmitted sexually and using a condom can go a long way in preventing such an occurrence. It is advised not to indulge with unprotected oral, vaginal or, anal sex in people infected with Dengue.



Diagnosis of Dengue

Complete blood work is generally required to diagnose Dengue. In this, the medical team treating the condition looks for the NS1 antigen, Immunoglobulin M, Immunoglobulin G, and they might also conduct the Dengue RNA PCR test to diagnose the nature of the occurrence and its severity.

NS1 antigen:

Looking for the presence of the NS1 antigen in the blood samples can help in the early diagnosis of Dengue. This is a faster process as it takes up to 4-5 days for the antibodies to get in the blood tests. Looking for the presence of the NS1 antigen is a good process to diagnose Dengue in the early stages as the chances of false positives goes up as the time frame gets near 5-7 days.

Looking for the NS1 antigen is the cheapest method of diagnosing Dengue. However, this form of diagnostic medicine does not reveal the nature of the virus-infection and which stage the patient is currently in.

Immunoglobulin M:

Immunoglobulin M (IgM) is an antibody found in the blood after the onset of the disease. Between 0-3 days the chances of finding Immunoglobulin M in blood are as high as 50% and the probability goes up to 80% by day 57 and 99% by day 10. This method can be used to diagnose whether the onset condition is primary or secondary in nature. It is called a primary onset when the patient/host is affected by Dengue for the first time in their life. And, secondary is when this is the second or third time they are getting infected by the virus.

The timelines for getting results vary between 1-2 days depending on the type of test conducted. That said, IGM can only be detected after the 4th day after the onset of the disease.

Immunoglobulin G:

The presence of Immunoglobulin G(IgG) in small quantities in the blood indicates that the person has been affected by Dengue in the past and this is a repeat occurrence. This helps classify the condition of the viral-infection, as Dengue in the second or third occurrence tends to be more severe and transitions quickly from mild Dengue to DHF and DHS rapidly.

IgG can only be detected after the 4th day after the onset of the disease.

Dengue RNA PCR test:

The RNA PCR test for Dengue is one of the most definitive and accurate tests whose results can be used in the early stages of the onset and these results identify the nature of the infection and also the stage, thereby, allowing the medical team treating the condition to prescribe medication that can curb the infection from becoming chronic and prevent multiple organ failure.

This form of diagnosing Dengue is best when the timeline of testing lies between 0-5 days from the onset of the condition. However, this form of testing is not available in every medical center.



Treatment of Dengue

Treatment of Dengue can be done either at home or at a medical facility depending on the severity of the condition. If the patient is suffering from just mild fever and body aches, they can be treated at home with oral hydration and Tylenol.

However, in conditions where the patient is showing symptoms of Haemorrhage or internal bleeding or shock or high fevers, it is advised to prescribe saline-based electrolytes to restore fluid content in the body. It is also advised to steer away from steroids and Aspirins.



Dengue fever complications

The complications of Dengue Haemorrhagic Fever include:

  • Bleeding under the skin
  • Bleeding on the skin
  • Patchy skin
  • Bloody Stool
  • Bloody vomit
  • Bloody Spit
  • Weariness
  • Cough and sore throat
  • Excessive sweating
  • High-fever
  • Sudden chills
  • Irregular urine discharge
  • Dry eyes



Outlook and Prognosis

Dengue as a condition is only fatal when left untreated and only 2.5% of all reported cases are caused by the DHF or DSS causing serotypes. The mortality rate of patients affected with DHF or DSS ranges between 20-50% as most cases are untreated.
Diagnosing Dengue is often difficult as it mimics the symptoms of Malaria and other mosquito-based illnesses. The viral fever duration ranges between 2-4 weeks depending on the nature of the condition. Rehydration through oral or saline drips.



Road to Recovery and Aftercare

The recovery period for Dengue patients ranges between 1-2 weeks depending on the nature of the condition and the physical fitness attributes of the patient. It is advisable to consult your treating physician about the Do’s and Don’ts in the recovery stage. From a diet perspective, it is advised to omit oily food, junk, and other fried food. Vegetables like Papaya, Broccoli, Pomegranate, Spinach, ginger-water, orange, coconut, and other boiled vegetables should be consumed as they contain Omega-3 which aids the body in strengthening the immune system. These fruits and vegetables have all the essential vitamins and minerals, fiber-content to boost the blood cell count and restore normal immunity levels.

Patients should also include protein-rich food like Fish, Chicken, egg, and milk products into their diet.

A doctor should be kept informed about the patient’s vitals during the recovery period. While the Do’s include regular monitoring of blood platelet count, blood pressure and adequate bed rest. The Don’ts require patients to stay away from products like coffee, alcohol, tobacco, and carbonated beverages.



Dengue FAQs: All your concerns addressed

Q.  What is Dengue?

  1. Dengue is a virus-based infection caused when a Male Aedes mosquito carrying the Dengue virus is transferred into a healthy host through a viremic process. In this, the patient suffers through headache, nausea, high fever, muscle aches, joint pains, bloody stools, bloody vomit, bloody spit, irritable eyes, blood scars under the skin, patchy skin, and blood scars over the skin.

Q.  What are the warning signs of Dengue?

  1. The most prominent warning sign is a high fever of 40°C or 104°F, accompanied by the
    following symptoms:
    ● Headaches
    ● Pain behind eyes
    ● Nausea, vomiting
    ● Swollen glands
    ● Joint, bone or muscle pains
    ● Rash
    In case of severe dengue, when the condition prolongs for more than 3-7 days, the signs
    and symptoms might turn into -
    ● Severe abdominal pain
    ● Persistent vomiting
    ● Bleeding gums
    ● Vomiting blood
    ● Blood in the stool
    ● Rapid breathing
    ● Fatigue/ restlessness

Q.  When should we do a dengue test?

  1. Dengue fever is a viral infection spread by mosquitoes, which easily spreads from person to person. A dengue fever test is conducted to detect the infection of the dengue virus. It is mostly used for people who have symptoms of illness and/or have recently traveled to an infected area. It is recommended to have a dengue test if you have -

    • Sudden high fever (104°F or higher)
    • Swollen glands
    • Rash on the face
    • Severe headache and/or pain behind the eyes
    • Joint and muscle pain
    • Nausea and vomiting
    • Fatigue
    • Severe abdominal pain
    • Vomiting that doesn't go away
    • Bleeding gums
    • Nose bleeds
    • Bleeding under the skin, which may look like bruises
    • Blood in urine and/or stools
    • Difficulty breathing
    • Cold, clammy skin
    • Restlessness

    Some of the common tests recommended for diagnosing dengue are -

    • Dengue NS1 Antigen
    • Immunoglobulin M (IgM)
    • Immunoglobulin G (IgG)
    • Dengue RNA PCR test

Q.  Is Dengue a communicable disease?

  1. No, generally Dengue is only caused when the virus-carrying vector bites a healthy host. However, in small cases, it is sexually transmitted. There have also been occurrences when pregnant women, when affected have seen the virus spread to the unborn child in the womb.

Q.  What are the different types of Dengue?

  1. Dengue is majorly classified into Mild Dengue Fever, Dengue Hemorrhagic fever, and Dengue Shock syndrome. Mild Dengue Fever is the most commonly occurring form of Dengue and is non-fatal. However, Dengue Hemorrhagic fever and Dengue Shock Syndrome is fatal when left untreated as the patient experiences blood loss, dehydration and a significant drop in blood pressure.

Q.  Can dengue be cured at home?

  1. Yes, Dengue can be treated at home depending on the nature of the onset condition. However, it is advisable to consult a medical practitioner before taking a decision on this.

Q.  Is hospitalization required for dengue?

  1. Yes, Dengue can be treated at home depending on the nature of the onset condition. However, it is advisable to consult a medical practitioner before taking a decision on this.

Q.  Is vaccination available for Dengue?

  1. Currently, there is no vaccination available for Dengue fever. However, the World Health Organisation and other medical communities are rigorously working towards it.

Q.  Is Dengue a deadly disease?

  1. Dengue Fever is a deadly disease when left untreated. The mortality rate in patients affected by Dengue ranges between 20-50%. However, with proper medication and care, patients can recover and resume normal lives in 2-3 weeks after the onset of the disease.

Q.  What are the best foods to recover from dengue fever?

  1. Here’s a list of a few of the foods loaded with essential nutrients and vitamins which ensures a speedy recovery from Dengue - 

    • Papaya Leaves
    • A mix of herbs like tulsi, giloy, ashwagandha, ginger, and aloe vera.
    • Pomegranates
    • Coconut Water
    • Turmeric
    • Fenugreek (methi)
    • Orange
    • Broccoli
    • Spinach
    • Kiwi Fruits

Q.  What should not be eaten in dengue?

  1. Recovering from a dengue attack is very tough. Though there are no specific dietary restrictions, you can build an easy and fruitful recovery process by adhering to a diet -

    • That is less oily and spicy
    • Try to consume food items that are easy to digest.
    • Avoid non-vegetarian food
    • Avoid Caffeinated beverages
    • Up your fluid intake and
    • Consume warm water instead of normal water.

Q.  Will Dengue spread to my baby if I’m pregnant?

  1. Yes, there have been instances where the disease-causing virus was transmitted from the mother to the fetus. Pregnant women should take care to ensure that there are no breeding grounds present around their homes in the form of stagnant water in flower pots, tyres, and buckets.

Q.  What is the treatment plan for a person affected by Dengue?

  1. There are no cure or treatment options currently available in the medical community. However, there are medications that patients are introduced to deal with the symptoms, such as Tylenol, pain killers, and muscle relaxants. Along with these, the patient is asked to take adequate bed rest, including a lot of vegetables and protein-rich food like eggs, pulses, chicken, and fish in their diet to boost blood cell count and accelerate the growth of the immune system.

Q.  What do we do when a Dengue epidemic occurs?

  1. When you start noticing Dengue symptoms in people around you, it is advised to alert the medical authorities and ensure that there are no breeding grounds near your residence. To ensure that you are not affected by this viral fever, installing window and door screens is a must to prevent mosquitoes from entering your home.

Q.  I had got Dengue before, Am I immune to it now?

  1. It depends on the type of serotype that you were infected with when you were first diagnosed with Dengue Fever. It is very unlikely that the same patient can be affected by the same strain of Virus again, however, when the patient is affected, the second or third time, it is more serious and fatal.



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