Dengue Fever

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• Dengue fever
• What causes dengue fever?
• What are the symptoms of dengue fever?
• How is dengue fever diagnosed?
• How is dengue fever treated?
• What are the preventions of dengue fever?
• FAQ

Dengue fever

 is a disease caused by the dengue virus, transmitted to humans through the bite of infected mosquitoes, specifically the Aedes aegypti mosquito. Four dengue virus strains (DENV-1 to DENV-4) can cause dengue fever. People with dengue fever may have no symptoms or experience high fever, headache, muscle and joint pain, nausea, vomiting, and small red or bleeding spots on the skin. Severe dengue fever can lead to dengue hemorrhagic fever, resulting in circulatory system failure, shock, and even death. It is crucial to seek medical attention promptly if you suspect dengue fever.

What causes dengue fever?

Dengue fever is due to infection with the dengue virus (DENV), which belongs to one of four strains: DENV-1, DENV-2, DENV-3, or DENV-4. The virus is transmitted through the bite of the Aedes aegypti mosquito, also known as the yellow fever mosquito. These mosquitoes are active during the daytime and typically feed on humans. When an infected mosquito bites a person during the fever or viremic  phase (when the virus is present in the bloodstream), the dengue virus can enter the cells of the mosquito's stomach and salivary glands. The virus then undergoes an incubation period of 8 - 12 days within the mosquito. When the infected mosquito bites another person, it can transmit the virus into the bloodstream of the bitten person, causing dengue fever symptoms to develop within 3 - 15 days.

What are the symptoms of dengue fever?

In the initial infection with a dengue virus (DENV), over 90% of cases have no symptoms or experience mild symptoms similar to those of the common cold. Symptoms typically appear 4-10 days after being bitten by an infected mosquito and beyond the virus's incubation period. In cases of a second infection with a different strain of the dengue virus, symptoms can progress to severe dengue fever (dengue hemorrhagic fever). There are three phases of dengue fever symptoms:

1. Febrile phase, this phase is characterized by sudden onset of high fever, typically ranging from 39-40 degrees Celsius, lasting 2-7 days. Other symptoms during this phase may include:
   • Headache, red face
   • Eye pain, pain around the eye socket
   • Nausea and vomiting
   • Muscle pain
   • Poor appetite
   • Joint pain, bone pain
   • Petechiae or numerous tiny red rashes flare up the body’s skin
   • Abdominal pain (right rib region) is possible, tenderness around the epigastric area.
2. Critical phase, this is the second phase, occurring around 3-7 days after the febrile phase. Most infected people do not enter this phase. It is the most crucial period for close monitoring. It can involve complications such as shock from high fever or internal bleeding caused by plasma leakage from blood vessels into body cavities, such as the chest, liver, or abdomen. Symptoms during this phase may include:
   • Severe stomach pain (especially in the right upper quadrant, caused by an enlarged liver) 
   • Persistent nausea and vomiting, anorexia
   • Abnormal bleeding
   • Bleeding gums, nosebleed
   • Bloody urine, stools, or vomiting blood (black vomit: Melena)
   • Petechiae or numerous tiny red spots on the skin
   • Breathing difficulty, rapid breathing
   • Restlessness
   • Fatigue, weakness, and lethargy
   • Cold extremities
   • Sweating 
   • Decreased urine output
   • Rapid pulse
   • A large amount of menstruation or a prolonged period of menstruation (in females)
   • Hypovolemic shock, which typically occurs 3-8 days after the onset of high fever
   • Fever drops quickly (often in conjunction with shock)
   • Gastrointestinal bleeding (often associated with shock)
   • Blood pressure fluctuations, inability to measure pulse, or low blood pressure in those with severe symptoms
   • Circulatory failure or dengue shock syndrome
   • Potential death
3. The recovery phase is the final stage of dengue fever. Individuals who have passed the febrile phase without entering the critical phase, or those who have recovered from the critical second phase for 1-2 days, will reach the recovery phase. During this phase, the body gradually recovers, and various symptoms of dengue fever gradually improve. Blood vessels regain normal wall integrity. Signs of the recovery phase include:
   • Overall improvement of symptoms
   • The fever subsides and the body temperature returns to normal.
   • Blood pressure and pulse rate rise.
   • Increased urine output
   • Shrink in size of enlarged liver within 1-2 weeks.
   • Improved appetite
   • Appearance of small white skin patches within larger red area.

How is dengue fever diagnosed?

The doctor diagnose dengue fever by taking a medical history, including any contact with mosquitoes, travel history to endemic areas, and conducting a preliminary physical examination to assess symptoms and differentiate dengue fever from other similar diseases such as common cold, Zika fever, Chikungunya fever, or malaria. Additional diagnostic methods used by doctors to confirm dengue fever may include the following:

• Tourniquet test: Examination for petechiae or bleeding spots under the skin or using a tourniquet test. This test involves using a tight band or a blood pressure cuff wrapped around the upper arm for a specific period to count the number of bleeding spots under the skin.
• Complete blood count (CBC) to check for changes in blood components such as platelets, red blood cells, and white blood cells. Decreased platelet count and increased hematocrit (concentration of red blood cells) may indicate leakage of blood vessels, which is a sign of dengue fever.
• Specific immunological tests for dengue fever, such as Dengue NS1 antigen, Dengue IgM, and Dengue IgG, to detect antibodies produced by the body in response to dengue virus infection.
• Molecular genetic testing, such as polymerase chain reaction (PCR), to detect the genetic material of the dengue virus. This test is usually done in the early stage of symptoms to confirm the disease and identify any of the four strains of dengue viruses that are the leading causes of dengue fever.

How is dengue fever treated?

• Once the diagnosis is confirmed, the doctor will treat the dengue fever to help the infected person return to a normal state as quickly as possible. For individuals experiencing symptoms from the febrile phase and the critical phase and diagnosed with blood vessel leakage, the doctor will closely monitor them within 24-48 hours to prevent shock and provide treatment using the following methods:
• Fluids replacement In individuals who have significant fluid loss, persistent vomiting or diarrhea, low blood pressure after febrile phase, loss of appetite, or refusal to consume food or water, the doctor may consider administering fluids or saline solution through a vein to compensate for the lost fluids.
• Strong pain relievers, such as paracetamol or acetaminophen, are given to reduce fever and alleviate muscle and joint pain.
• ORS-Oral rehydration salt may be provided to compensate for the lost fluids in the body and prevent dehydration.
• Blood transfusion: In cases with significant internal organ hemorrhage or bleeding through menstruation, vomiting, or bowel movements, the doctor may consider giving blood transfusion to prevent shock from the blood loss.

In addition to the treatment, periodic blood tests are required to monitor thrombocytopenia, low white blood cell count, concentrated red blood cell count, or low blood pressure.

What are the complications of dengue fever?

• Dengue hemorrhagic fever can cause visceral hemorrhage, which can lead to internal organ failure, low blood pressure, and shock, all of which can lead to death.
• Mother-to-child viral transmission during childbirth: Dengue virus transmission from mother to child occurs during natural childbirth in dengue-infected mothers. In addition, mothers who contract dengue fever during pregnancy are at a higher risk of premature birth, low birth weight babies, fetal death, and mother-to-child viral transmission.

Can you have dengue fever reinfection?

Throughout life, humans are susceptible to multiple infections with any of the four strains of the dengue virus. If a person has had an infection by a particular viral strain, the body will develop immunity to that specific viral strain for life. However, they will not have immunity to the other three strains and may only have transient antibodies to any one of them if infected. The severity of dengue fever symptoms tends to increase with each subsequent infection, such as during the second, third, or fourth dengue infection.

What are the preventions of dengue fever?

• Apply mosquito repellent, wear long sleeves, long pants, and socks, or wear clothes with a mosquito repellent coating to protect yourself from mosquito bites.
• Use DEET-containing mosquito repellents to keep mosquitoes at bay.
• Eliminate mosquito breeding sites, particularly pools of stagnant water, inside and outside the home, and always cover containers or bins with lids.
• Close the windows to prevent mosquitoes from entering. Install the mosquito net on the door premise or sleep in a mosquito net to avoid getting bitten by mosquitoes.
• Dengue vaccination: The new 4 serotype dengue fever vaccine against 4 new types of dengue fever, the newest version of the dengue vaccine that was developed to cover all 4 strains of dengue viruses, is recommended for those aged 4 years and above. Those with healthy immunity, as well as parents or guardians of children aged 4 and up, including all family members, are encouraged to bring their children to get vaccinated against dengue fever at any available hospital.

How to manage dengue fever at home?

• Take pain relievers, such as paracetamol or acetaminophen. Do not use aspirin, ibuprofen, or nonsteroidal anti-inflammatory drugs (NSAIDs), as they may cause excessive bleeding.
• Periodically take sips of ORS-Oral rehydration salt to replenish water loss in the body, especially for those constantly vomiting.
• Wipe down the body with warm water regularly to help reduce body temperature.
• Eat soft, easily digestible foods and drink plenty of water to avoid dehydration.
• Monitor the symptoms; if the fever is high and does not respond to pain medication, see a doctor.

Dengue Vaccine

Currently, dengue fever can be prevented by receiving the New 4 Serotype Dengue Fever Vaccine, which covers all 4 strains of dengue virus and can be administered from age 4 years and above who used to have or have never had dengue fever before without the need to draw a blood sample for an antibody test. The New 4 Serotype Dengue Fever Vaccine is considered a safe and effective vaccine in preventing dengue fever by up to 80.2%, reducing the risk of recurrence, and preventing hospitalizations by up to 90.4%.

Dengue fever: A close threat that can be prevented and treated

Dengue fever poses a significant threat to human life. This fever is prevalent in tropical countries and follows an epidemic cycle closely tied to the rainy season. Presently, dengue fever claims numerous lives worldwide each year, and unfortunately, there is no specific antiviral medication available for symptom treatment. To minimize the risk of dengue virus infection, it is crucial to take preventive measures such as avoiding mosquito bites, eliminating breeding sites, and considering preventive dengue fever vaccination against dengue viruses for those who previously had or have never had dengue fever to reduce the risk of recurrence.

In cases where individuals experience persistent high fever, prolonged vomiting, intense abdominal pain, rapid heartbeat, decreased urine output, restlessness, extreme fatigue, and lethargy, seeking immediate medical attention from a qualified healthcare professional at a hospital is imperative. This timely intervention not only aids in receiving appropriate treatment but also helps prevent potential complications and promptly alleviates the symptoms associated with dengue fever.

FAQ

1. How long does dengue fever last?
   Usually, the duration of dengue fever ranges from 3 to 7 days, during which individuals may experience either no symptoms or symptoms characterized by high fever. Subsequently, fever and accompanying symptoms will gradually diminish and show signs of improvement. Individuals with severe dengue symptoms should seek prompt medical care at a hospital for close monitoring by healthcare professionals.
   
   
2. Is dengue fever contagious?
   In contrast to influenza, dengue fever does not exhibit direct person-to-person transmission. Instead, it is mainly transmitted by Aedes aegypti mosquitoes, which acquire the dengue virus by biting an infected individual and subsequently pass on the virus by biting another person. The direct transfer of the dengue virus from one person to another can only occur during childbirth when the newborn comes into contact with the mother's blood.
   
   
3. Which foods should be abstained from during dengue fever?
   When ill with dengue fever, one should avoid consuming foods with dark hues, such as black or red. This precaution is essential to prevent confusing between stools that may appear bloody due to eating certain foods and those caused by dengue hemorrhagic fever.
   Additionally, it is advisable to refrain from consuming sour and spicy foods, and hard and crunchy foods, as they can cause gastrointestinal irritation and exacerbate stomach ulcers.

Related Package

• 4-Serotype Dengue Vaccine Package (2 doses)