Dengue: Symptoms, causes, prevention, treatment and platelet count

Table of contents

• What is dengue?

• What is Dengue virus?

• Environmental factors

• 10 Common symptoms of dengue

• 7 dengue warning signs to stay alert for!

• How Does Dengue Spread?

• Dengue prevention

• Dengue Platelet Count

• Normal platelets in human body

• Dengue platelet count danger level

• Minimum platelet count for dengue

• What happens to the platelet count in dengue?

• Who needs platelet transfusion?

• Dengue treatment

• What should a patient of dengue eat?

• Is there a vaccine available against dengue?

• Take home message

• FAQ on dengue fever and platelet count

What is dengue?

Dengue is a kind of acute viral disease that is spread by mosquito bites. It’s also called breakbone fever , because of the severe body pain it causes to the patient that feels as if the bones are breaking. It is, however, seasonal to a very large extent, but its consequences can vary from normal to severe. India faces a large number of deaths every year due to the outbreak of dengue. States like Kerala, Odisha, Telangana, Maharashtra etc are particularly vulnerable. 

What is Dengue virus?

• Dengue Virus, often abbreviated as DENV, is responsible for causing this disease.

• It has 4 serotypes, meaning there are 4 different varieties of the same virus (DENV1, DENV2, DENV3, DENV4). Once affected by a particular type of virus, even if the immune system offers protection against the same type, next time it’s still possible to be affected by the other types. 

• So, it means that a single person can be affected by Dengue fever four times in their lifetime.

The winged villain: Aedes mosquito

When the infected mosquito bites a person, the virus gets transmitted to him/her. It can also be vice-versa, i.e. if a mosquito bites an infected person, then the mosquito itself becomes a carrier of the virus, thereby spreading to other humans. 

• The female mosquito of the Aedes species (Aedes aegypti and Aedes albopictus) transmits the virus via it’s bite.

• The same mosquito also spreads other deadly diseases like chikungunya, Zika, etc.

• It can be identified by the stripes on its body ( also called Tiger mosquito).

• It breeds in artificial stored water like fountains, flowerpots etc.

• Usually bites during daytime.

Environmental factors

• Environment factors like rain, hot and humid climates, lack of cleanliness, etc. negatively impact dengue frequency. The prevalence of the disease can largely be seen in Asia and the countries of Southern America which are tropical areas. There are 100 to 400 million dengue cases worldwide, which has spiked in recent decades. India is very prone for developing dengue cases, hence it makes it important for us to know about this diseases.

• While most of the dengue viral infections are mild, sometimes it can end up as an acute flu-like illness which can develop into a potentially life threatening severe dengue fever.

• This makes it important for us to know about the different symptoms and warning signs of dengue fever.

10 Common symptoms of dengue

Following are some of the well-known symptoms of the Dengue Virus that show up in a person:

1. Spike in temperature: The most common symptom of dengue is high fever. The temperature in dengue patients generally rises to more than a level of 102-degree Fahrenheit. This fever can last for 5-7 days.

2. Headache: People who have been a victim of Dengue experience severe headaches which sometimes become extremely unbearable.

3. Body Pain: Muscle and joint pain is a common complaint noticed among dengue patients, which gives dengue the name ‘breakbone fever'.

4. Pain behind the eyes: It’s a very common symptom , and this pain usually is seen increasing on eye movement, on applying pressure on the eyes or while seeing bright lights.

5. Cough and cold are common in very mild cases.

6. Altered taste in the mouth.

7. Constipation.

8. Abdominal pain, vomiting.

9. Excessive fatigue and tiredness. 

10. Body Rashes: Rashes can be seen in about 80 % of the cases. These are pinpoint rashes which are seen commonly over the face , neck and chest and rarely may spread to the hands and feet. These rashes may be accompanied by itching.

• Mild dengue disease usually resolves in a week. But sometimes, it can progress into a more severe form which can be detected early if we know about certain warning signs of severe dengue fever.

7 dengue warning signs to stay alert for!

1. Severe abdominal pain.

2. Continuous excessive vomiting.

3. Bleeding gums or bleeding from nose spontaneously.

4. Blood in vomit.

5. Blood in stools or black / dark stools.

6. Breathing difficulty.

7. Persisting rashes or rashes increasing in size.

• If such symptoms are noted, immediate medical consultation is necessary.

• Many of these symptoms and warning signs closely resemble other diseases like malaria, typhoid etc. Therefore, humans tend to neglect these symptoms until the level of their intensity increases. We must take the required steps to eliminate dengue in the longer run.

How Does Dengue Spread?

Dengue fever, a virus transmitted by mosquitoes, has the potential to spread rapidly within communities if we underestimate how it is transmitted. Let's take a look, at the ways this stealthy virus can spread;

• Mosquito Carriers: The main culprits are Aedes mosquitoes, Aedes aegypti. These mosquitoes become infected when they feed on individuals carrying the virus. Once infected they can unknowingly transmit the virus to humans through their bites. It's like these insects are unwittingly acting as vehicles for the virus.

• Human Contact: When an infected mosquito bites a person it's like a transfer of a package. The virus enters the person's bloodstream through the mosquito's bite turning the mosquito into a carrier of infecting people with subsequent bites.

• Vertical Transmission: This is a route of transmission. An infected pregnant woman can pass on the virus to her baby during pregnancy or childbirth. Although rare this is a way in which the virus can be passed from one generation to another.

• Blood Transfusions: A known mode of transmission occurs through blood transfusions from an infected donor to a recipient. However, screening processes have significantly reduced this risk.

Dengue prevention

The answer is ‘ Yes ‘ ! If we take the following simple precautionary measures, we can definitely prevent dengue: 

1. Remove Aedes mosquito breeding areas like fountains, flowerpots and other stagnant water around the house.

2. Use of mosquito nets while sleeping. 

3. Use of appropriate mosquito repellants in outdoor areas. 

4. Wearing long sleeved clothes to protect from bites. 

5. Be aware if you’re travelling to a dengue prone area while going on international trips. 

Dengue Platelet Count

• A very common question that arises revolving dengue fever is : Does dengue reduces platelets in our blood ? The answer is ‘Yes ‘ ! Dengue does reduces platelets counts. 

• Before we talk more about the relationship between dengue and platelets, we need to know about the status of normal platelets in human body.

Normal platelets in human body

• Platelets are one of the smallest cells in our human body , which get their name from their plate- like shape. Whenever there is any damage to a blood vessel, platelets are immediately signalled to go to that injured vessel and form a clot to repair the injury. 

• The average number of platelets in human body is between 1.5 to 4 lakhs . This is the ideal platelet count in most of the individuals. ( this value can vary with the age of the patient and pregnancy - the mean value is usually lesser in pregnant females ).

• If a person has higher platelet count, i.e.,when the maximum platelets in human body goes more than 4,50,000, then the situation is referred to as Thrombocytosis, while lesser than 1,50,000 platelets are called Thrombocytopenia.

Dengue platelet count danger level

Dengue fever, an illness caused by mosquito-borne viruses can lead to a condition called dengue. One important indicator to pay attention to is your platelet count, which is a component in your blood that helps with clotting. Having a platelet count can result in complications related to bleeding which can be quite serious. Here's what you should know;

• Platelet Range; A normal platelet count typically ranges from 150,000 to 450,000 per microliter of blood. However, in cases of dengue fever, the count can drop significantly.

• Mild Decrease; It is common for there to be a decrease in platelet count during dengue fever and often it doesn't require any special treatment. At this stage, you might experience symptoms such as fever, headache, joint pain and rash.

• Moderate Decrease; If your platelet count falls below 50,000 it's important to exercise caution. You might notice bleeding from the nose, gums or skin.

• Severe Decrease; When the platelet count drops below 20,000 it becomes a cause for concern. Watch out for signs of bleeding such as blood, urine vomit or black stools. In cases immediate medical attention is necessary.

Minimum platelet count for dengue

When it comes to dengue fever, understanding the level of platelets in your blood is like having a key to solving a puzzle. Platelets are blood cells that play a role in clotting. During this infection being aware of your platelet count becomes extremely important. Here's some essential information for you;

• Dengue Impact; Dengue can cause a decrease in platelet count, which may result in bleeding problems.

• Critical Zone; If your platelet count drops below 20,000 it indicates danger. At this stage the risk of bleeding increases.

• Seek Medical Attention; Low platelet counts, below 20,000 require medical care. Be vigilant for signs such as nosebleeds, gum bleeding or dark stools that might indicate bleeding issues.

What happens to the platelet count in dengue?

• In our body, platelets are produced by the bone marrow throughout our lifetime. Dengue virus specifically affects this mechanism, thereby affecting platelet production. The virus also destroys the functioning platelets in circulation not directly, but by other complicated mechanisms. This is why in dengue, platelet level falls. Because of this fall from the ideal platelet count in dengue, the body is unable to form clots, thereby leading to both internal and external bleeding. This fall in platelet count in dengue can also impact the recovery process negatively, which can ultimately lead to multiple organ failure.

• But it is to be remembered that, in only 10-20% of the cases of severe dengue fever, platelet count reduces to less than 20000. This is when the platelet counts are said to hit dangerous levels in dengue. These are the patients who experience severe internal as well as external bleeding in their stools, vomit , growing rashes etc.

• It is understandable that as the platelet count in dengue keeps falling, the symptoms of bleeding and rashes keep worsening.

• In the rest of the 80-90% cases of mild-moderate dengue fever, platelet count range usually doesn’t fall below 1 lakh. Even upto 50000 platelets in dengue, some patients don’t experience severe symptoms. 

Who needs platelet transfusion?

• A common understanding is that the total blood platelets range in dengue is a measure of the severity of the disease. Even though this may be true, it’s not entirely necessary to transfuse platelets from outside to every patient with reduced platelet count in dengue.

• This is because in most of the patients of dengue fever, platelet counts improve by themselves and we just need to maintain proper hydration using IV fluids and other supportive therapy.

Now a question may arise in your minds : Why can’t every patient receive a platelet transfusion to reach the ideal platelet count in dengue ? Let’s see why. 

Platelet transfusion, like any other blood product transfusion, is not without its risks:

1. risk of transmitted infections.

2. Serious allergic reactions ( called anaphylaxis) which can be life- threatening. 

3. Lung and heart damage can happen rarely.

The above dangerous side effects of platelet transfusion makes it important not to over prescribe platelets to all patients with low platelet count in dengue. 

Dengue treatment

• As per the World Health Organization, Dengue has no specific treatment, but the only thing that could help is the early detection of the disease so that necessary steps could be taken to improvise a patient's situation. 

• If you're facing the symptoms resembling dengue and you have been positively diagnosed for the disease, you may need responsive medical support that comprises blood pressure monitoring, fluid management , medications for fever and body pain, regular monitoring of the platelet counts and platelet transfusion if necessary.

• Therefore, identifying the symptoms is an essential task in the first place to curb the disease in a limited time frame as early diagnosis is the only key to fight dengue.

What should a patient of dengue eat?

Intake of a proper diet is very important to hasten recovery and also to optimise the platelet counts in dengue.

1. plenty of oral fluids to main adequate hydration. 

2. Green leafy vegetables.

3. Plenty of fruits.

4. Iron rich foods. 

5. Foods rich in Vitamin C like citrus fruits and in vitamin K.

Is there a vaccine available against dengue?

Yes ! A vaccine called Dengvaxia ( also known as CYD-TDV) was approved in 2015 for prophylaxis against dengue virus. It is usually given in 3 doses at 6 month intervals. But studies have shown that the main problem with this vaccine is that it is recommended only for people who have previously been affected by the virus , because if given in a person who has not been previously affected, administering the vaccine may actually increase the risk of severe dengue. So, testing for presence of antibodies ( called sero positivity- means evidence of previous infection) is important before administering the vaccine. 

Take home message

Even though dengue has the capacity to become life threatening, it is still a preventable disease, so it’s in our hands to curb the disease from spreading. So remember the following:

• Get rid of stagnant water around your surroundings.

• Protect yourselves from mosquito bites using repellents and nets and full-sleeved clothes. 

• If dengue is suspected, reach out to your physician immediately for further diagnosis and treatment. 

• Maintain proper hydration and a healthy diet if diagnosed and follow the instructions offered by your treating physician.