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Dengue Virus Infection Overview

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What is dengue causes symptoms transmission and prevention

Dengue is a transmitted disease and it may have major consequences to any person. The pronunciation of dengue is den-gey. It is caused by female mosquitoes, named Aedes mosquitoes. It is most seen and felt in tropical and subtropical areas such as the torrid zone. Dengue is caused by the mosquitoes when they bite you, and this generally happens in the daytime. These mosquitoes are generally found in human habitats. Dengue is a major disease and in fact, nearly 400 million people in this entire world are affected by it in a year. The more basic way to understand this is that every one mosquito in every four mosquitoes is a female Aedes mosquito that causes dengue. This virus is so deadly that it might affect an individual four times in his lifetime.


Causes of Dengue:

Now, let us discuss the causes of dengue. Many different ways can cause dengue -

A mosquito can cause death, we will ponder over those causes.

1. Mother to child - The dangerous thing is that the dengue virus can also affect a fetus or womb of a mother. This means that if the mother is suffering from dengue and she is pregnant, the disease will pass on to the baby as well. It is also a known fact that dengue can be transmitted through breastfeeding.


2. Mosquito bites - This is the most common method of getting infected by this disease. If a mosquito bites you and if that mosquito is a dengue mosquito, you will need treatment as the chances of you getting infected is one hundred percent.


3. Other miscellaneous sources - Other scientific methods or biological methods of transmitting the disease are organ transplant, blood transfusion, etc. Now, let us study some symptoms that you might notice when a dengue mosquito bites you.


The following are the major common symptoms of dengue, read them and be aware of your body and its symptoms. The symptoms and signs might vary from major to normal. Sometimes these symptoms can be life-threatening. Take the guidance of a doctor whenever you feel that something is off like you have Swollen glands, rashes, fall in blood pressure, nausea and vomiting, bleeding from gums and nose, pain in joints and muscles, severely, blood while excreting, vomiting, and urine, no appetite or loss of appetite, difficulty in taking in oxygen or clammy skin straight away contact your doctor ahead. 


These symptoms might or might not be curable. You must go to a professional or a doctor to get yourself tested and to have the right treatment.


Symptoms of Dengue


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About one in four dengue virus-infected people gets sick. The signs and symptoms can vary from mild to severe. Severe dengue fever or dengue haemorrhagic fever can be life-threatening, and the patients need to be hospitalized immediately. The common symptom is high fever along with the following

  • Rash.

  • Nausea and vomiting.

  • Severe joint and muscle pain and abdominal pain.

  • Bleeding from nose and gums.

  • Loss of appetite.

  • Blood in stool, urine and vomit.

  • Difficulty in breathing.

  • Clammy or cold skin (shock).

  • Restlessness and sudden fall in blood pressure. 

  • Swollen glands. 

These symptoms usually persist for 2-7 days. Then the patients typically recover within a week. 


Dengue Treatment

To date, no vaccine or medicine has been developed. But for patients with mild symptoms can 

  • Rest as much as possible.

  • Drink lots of fluid (water, drinks with electrolytes) for extra hydration.

  • Take paracetamol to relieve pain or control fever. 

For a severe condition, the patients need to seek hospitalization and may require blood transfusion or intravenous fluid supplementation. 


Dengue Prevention 

Only the preventive measures of Dengue can effectively safeguard thousands of people against this disease. 

Infected people should stay in isolation and indoors until all the symptoms subside (3-5 days). Apart from that, the following guidelines need to be maintained to remain safe. 

  • One of the valid dengue reasons includes waterlogging. These mosquitoes typically lay eggs and breed in clean stagnant water. Therefore, get rid of all nearby standing water sources. Also, change the water of flower vases daily. 

  • Try to stay at well-screened houses and keep all the doors and windows shut especially during dawn, dusk and night as well. The Aedes mosquitoes can bite during both daytime and night too. 

  • Use mosquito repellents containing at least 10 percent concentration of DEET throughout the day. Also, use mosquito nets while sleeping.  

  • Wear long-sleeved pants, shirts etc. when you have to travel to mosquito-infested areas. 

  • Daily remove the garbage and waste and keep your surroundings clean. 

Once you know about the causes of Dengue, take protection accordingly to fight against dengue viruses. 

Now, it’s time for a quick quiz on Dengue!

  1. Bleeding in dengue causes a decrease in _________________ level. 

  2. Antibiotics can cure dengue fever. True/False

Ans: 1- Platelet. 2- False. 


For further information regarding the causative organism of dengue fever, stay tuned to Vedantu’s app! Also, go through the rest of the study materials available on our website to master other chapters of Biology.

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FAQs on Dengue Virus Infection Overview

1. What is dengue?

Dengue is a mosquito-borne viral infection caused by the dengue virus (DENV) and transmitted mainly by Aedes aegypti mosquitoes. It is common in tropical and subtropical regions and can range from mild fever to severe disease.

  • Caused by four serotypes: DENV-1, DENV-2, DENV-3, DENV-4
  • Spread through the bite of infected female Aedes mosquitoes
  • Also called “breakbone fever” due to severe muscle and joint pain

2. How is dengue transmitted?

Dengue is transmitted through the bite of an infected Aedes mosquito, primarily Aedes aegypti. The mosquito becomes infected when it bites a person who already has the virus in their blood.

  • Step 1: Mosquito bites an infected person
  • Step 2: Virus multiplies inside the mosquito (extrinsic incubation)
  • Step 3: Infected mosquito bites another person and transmits the virus
Dengue is not spread by direct person-to-person contact.

3. What are the symptoms of dengue fever?

The symptoms of dengue fever include high fever, severe headache, joint and muscle pain, and skin rash. Symptoms usually appear 4–10 days after a mosquito bite.

  • Sudden high fever
  • Severe headache and pain behind the eyes
  • Muscle and joint pain (breakbone fever)
  • Nausea, vomiting, and rash
Severe cases may progress to dengue hemorrhagic fever or dengue shock syndrome.

4. What causes severe dengue?

Severe dengue is mainly caused by a secondary infection with a different dengue virus serotype, leading to an exaggerated immune response. This process is linked to antibody-dependent enhancement (ADE).

  • Increased blood vessel permeability
  • Plasma leakage and internal bleeding
  • Low platelet count (thrombocytopenia)
Severe dengue can result in dengue hemorrhagic fever and life-threatening shock.

5. What is the life cycle of the dengue virus?

The life cycle of the dengue virus involves transmission between humans and mosquitoes with viral replication in both hosts. In humans, the virus infects immune cells and multiplies.

  • Entry into human blood through mosquito bite
  • Infection of monocytes, macrophages, and dendritic cells
  • Viral replication and release into bloodstream (viremia)
  • Uptake by another mosquito during blood meal
This cycle maintains dengue transmission in endemic areas.

6. What is the structure of the dengue virus?

The dengue virus is an enveloped, single-stranded RNA virus belonging to the genus Flavivirus. It has a spherical structure about 50 nm in diameter.

  • Genetic material: positive-sense single-stranded RNA
  • Outer lipid envelope
  • Surface proteins: E (envelope) protein and M (membrane) protein
The E protein helps the virus attach to and enter host cells.

7. How is dengue diagnosed?

Dengue is diagnosed using blood tests that detect the virus, its genetic material, or antibodies produced by the immune system. Early diagnosis is important for monitoring complications.

  • NS1 antigen test (early infection)
  • RT-PCR to detect viral RNA
  • IgM and IgG antibody tests (later stages)
A low platelet count and increased hematocrit also support the diagnosis of dengue infection.

8. What is the difference between dengue fever and dengue hemorrhagic fever?

Dengue fever is a mild to moderate viral illness, whereas dengue hemorrhagic fever (DHF) is a severe form characterized by bleeding and plasma leakage. Both are caused by the same dengue virus but differ in severity.

  • Dengue fever: High fever, pain, rash
  • DHF: Bleeding, low platelets, fluid leakage
  • DHF may progress to dengue shock syndrome
Severe forms require immediate medical attention.

9. How can dengue be prevented?

Dengue can be prevented by controlling mosquito populations and avoiding mosquito bites. Since there is no specific antiviral cure, prevention is the most effective strategy.

  • Eliminate stagnant water where Aedes mosquitoes breed
  • Use mosquito repellents and bed nets
  • Wear long-sleeved clothing
  • Community vector control programs
Vaccination is available in some countries under specific medical guidelines.

10. Is there a treatment or vaccine for dengue?

There is no specific antiviral treatment for dengue, and management mainly involves supportive care. Early medical monitoring reduces the risk of severe complications.

  • Maintain adequate hydration
  • Control fever with paracetamol (avoid aspirin due to bleeding risk)
  • Monitor platelet count and fluid balance
Vaccines such as Dengvaxia are approved in some regions for individuals with prior dengue infection.


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