KATHMANDU: Dengue fever, a mosquito-borne illness, continues to pose a significant health threat worldwide, with rising cases in many regions.

Caused by the dengue virus and transmitted by the Aedes mosquito, this disease can range from mild symptoms to severe, life-threatening complications.

In this article, we will explore the causes, symptoms, diagnosis, and treatment of dengue fever, along with preventive measures that can help reduce its spread.

With early detection and effective management, the impact of dengue can be minimized, but continued awareness and vigilance are key to controlling its rise.

A mosquito becomes infected when it feeds on a person who has the virus in their bloodstream. Dengue cannot be transmitted directly from person to person.

The disease results from the dengue virus, primarily transmitted to humans through the bite of infected Aedes mosquitoes, mainly Aedes albopictus and Aedes aegypti.

Dengue fever can range from a mild illness to a severe, life-threatening condition known as dengue hemorrhagic fever or severe dengue.

Serotypes

There are four serotypes of the dengue virus: DEN-1, DEN-2, DEN-3, and DEN-4, all belonging to the genus Flavivirus.

This article, written in Nepal News, provides information on the causes, symptoms, risk factors, diagnosis, treatment, complications, and prevention of dengue fever.

Causes of Dengue

Dengue fever is caused by four serotype viruses, all transmitted by the Aedes aegypti mosquito, and more rarely, by the Aedes albopictus mosquito. Infection occurs when an individual is bitten by an infected mosquito.

Transmission occurs after the mosquito’s incubation period, which is approximately 4-10 days.

Risk Factors for Dengue

• Weak immune system: Individuals with compromised immunity are more vulnerable to severe dengue infections.
• Traveling or living in endemic areas: Regions with high mosquito populations, such as subtropical areas, increase the risk of infection.
• Climate changes: Warm and humid climates favor mosquito breeding, enhancing transmission.
• Exposure to mosquito bites: People exposed to Aedes mosquitoes are at higher risk.
• Lack of mosquito control measures: Stagnant water, poor sanitation, and a lack of insecticide use contribute to higher transmission.
• Previous dengue infection: A second dengue infection can increase the risk of severe dengue.
• Pregnancy: Pregnant women may transmit dengue to their unborn child, raising the risks for both.
• Poor water management: Poor drainage systems contribute to mosquito breeding grounds.
• Urbanization: Urban areas with poor sanitation often provide ideal conditions for mosquito breeding.
• Age: Elderly people and young children are more vulnerable to severe illness.

Symptoms of Dengue

Symptoms of dengue fever typically appear 4-10 days after being bitten by an infected mosquito. The symptoms can range from mild to severe and may include:

• Nausea and vomiting
• Headache
• Eye pain
• Joint and muscle pain
• Skin rash
• Swelling
• Mild bleeding (such as gum bleeding or nosebleeds)
• Fatigue
• Loss of appetite
• Abdominal pain
• Restlessness
• Liver enlargement
• Fluid accumulation

Severe dengue can lead to organ damage, severe bleeding, and respiratory problems. Severe dengue, also known as dengue hemorrhagic fever or dengue shock syndrome, is a life-threatening condition.

Diagnosis

Laboratory Investigations:

• Dengue IgM/IgG antibody test
• Dengue NS1 antigen test
• Polymerase Chain Reaction (PCR) test
• Complete Blood Count (CBC)
• Nucleic Acid Amplification Test (NAAT)

Other Methods:

• Testing for other viruses that cause similar symptoms.
• Isolating the virus from body fluids.

Clinical Diagnosis: Clinicians assess the patient’s travel history, symptoms, and potential exposure to mosquitoes.

Management of Dengue

Management focuses on supportive care to alleviate symptoms and prevent complications. There is no specific antiviral treatment for dengue fever.

Mild Dengue Treatment:

• Rest
• Hydration: Drink plenty of fluids and water to prevent dehydration.
• Pain relief: Use paracetamol to reduce fever and muscle pain. Avoid ibuprofen, aspirin, and other NSAIDs.
• Monitor for warning signs of severe dengue.

Severe Dengue Treatment:

• Hospitalization for supportive care and close monitoring.
• Oxygen therapy if needed.
• Fluid replacement to maintain hydration.
• Blood transfusions if platelet count is critically low.

Prevention

• Control mosquitoes:
  • Use vaporizers.
  • Remove stagnant water around the home.
• Avoid mosquito bites:
  • Wear long clothes.
  • Sleep under a mosquito net.
  • Keep windows and doors closed when possible.

Complications

• Hepatomegaly (liver enlargement)
• Dengue encephalitis
• Myalgias (muscle pain)
• Myositis (muscle inflammation)
• Lymphadenopathy (swollen lymph nodes)
• Bleeding (nosebleeds, gum bleeding)
• Optic neuritis (inflammation of the optic nerve)
• Nausea and vomiting
• Blood vessel damage
• Joint pain
• Seizures
• Weakness
• Circulatory system failure
• Intracranial hemorrhage (brain bleeding)

Dengue fever is a major public health concern. Early diagnosis and supportive care can reduce complications and death. The most effective prevention involves stringent mosquito control and the practice of personal protective measures.