Dengue Fever in Nepal: Symptoms, Warning Signs and Hospital Treatment

Dengue fever has transformed from a sporadic import to an endemic vector-borne disease in Nepal over the past fifteen years. Pokhara has recorded outbreaks in every monsoon and post-monsoon season since 2010. Recognising dengue early, identifying the warning signs that require hospitalisation, and understanding why it can be dangerous for a second time are practical knowledge for everyone in Pokhara during peak season.

How Did Dengue Become Endemic in Nepal?

Nepal recorded its first confirmed dengue outbreak in 2006 in the Terai (lowland) districts. By 2010, dengue had reached Pokhara and the mid-hill districts. The combination of rapid urbanisation (creating stagnant water breeding sites), climate change extending the Aedes mosquito’s habitat to higher altitudes, and increased population movement accelerated the spread.

Nepal’s dengue epidemiology has worsened significantly since 2019. The 2022 outbreak was one of the worst on record, with cases across nearly all provinces. All four dengue serotypes (DENV-1 through DENV-4) have been identified in Nepal, which has critical implications for disease severity in individuals who experience a second infection.

What Are the Four Dengue Serotypes and Why Does a Second Infection Matter?

Dengue virus exists in four distinct serotypes (DENV-1, -2, -3, -4). Infection with one serotype produces lifelong immunity against that specific serotype, but only temporary cross-immunity against the other three.

A second infection with a different serotype carries substantially higher risk of developing severe dengue (previously called dengue haemorrhagic fever or dengue shock syndrome). The mechanism involves antibody-dependent enhancement (ADE) — antibodies from the first infection bind to the second serotype but cannot neutralise it, and instead facilitate viral entry into immune cells, amplifying the viral load and triggering a severe inflammatory response.

This is why dengue kills more adults and teenagers than children — they are more likely to have had a prior infection with a different serotype.

What Are the Classic Symptoms of Dengue Fever?

Dengue has an incubation period of 4–10 days after the mosquito bite. The onset is typically sudden:

• High fever: Abrupt onset, 39–40°C, lasting 2–7 days. In some cases, a second fever spike produces the classic “biphasic” or “saddle-back” fever pattern.
• Severe headache — frontal, often described as the worst headache the patient has had
• Retro-orbital pain: Pain behind the eyes, worsening with eye movement — highly characteristic of dengue
• Myalgia and arthralgia: Severe muscle and joint pain. This is why dengue is historically called “breakbone fever.”
• Rash: A maculopapular or petechial rash typically appears on day 3–5 of fever, spreading from the trunk.
• Thrombocytopenia: Platelet count falls as the illness progresses — a key laboratory finding.
• Leukopenia: Low white blood cell count (common in dengue; helps distinguish from bacterial infections).

What Are the Warning Signs of Severe Dengue?

The most dangerous period in dengue is the defervescence phase — when the fever breaks, usually around day 4–6. This is when plasma leakage and severe complications develop. The following warning signs require urgent hospital admission:

• Severe abdominal pain or tenderness
• Persistent vomiting (three or more episodes in 24 hours)
• Bleeding: Bleeding gums, nose bleeds, blood in urine, vomiting blood, black tarry stools
• Rapid breathing or difficulty breathing
• Fluid accumulation: Ascites (abdominal fluid), pleural effusion (fluid around the lung) — detectable on clinical examination or ultrasound
• Restlessness, irritability, or drowsiness — signs of reduced organ perfusion
• Sudden drop in platelet count to below 50 ×10⁹/L with any of the above
• Postural dizziness or cold/clammy extremities — early dengue shock

Important: A patient who felt like they were improving but then suddenly worsens is in the critical phase. Do not assume recovery because the fever has gone.

How Is Dengue Diagnosed?

Dengue diagnosis at A&B uses:

• NS1 antigen test (Days 1–5 of fever): Detects dengue viral protein. Highest sensitivity in the first three days.
• IgM and IgG antibodies (Typhidot / dengue serology): IgM rises from day 5; IgG from prior infection rises rapidly in secondary dengue.
• CBC with platelet count: Monitors leukopenia and thrombocytopenia — key for monitoring severity.

Results for NS1 and CBC are available within 2 hours at A&B. Clinical context (fever pattern, symptoms, monsoon season) is essential — no single test result should be interpreted in isolation.

How Is Dengue Treated?

There is currently no antiviral treatment for dengue. Management is entirely supportive:

Outpatient Management (Uncomplicated Dengue)

Most patients with dengue can be managed at home with:

• Paracetamol for fever and pain — do not use ibuprofen or aspirin, which increase bleeding risk.
• Oral rehydration: Dengue causes significant fluid losses through sweating and vomiting. Adequate fluid intake (2–3 litres per day in adults) is the most important home treatment.
• Rest and mosquito net use (to prevent transmission to other family members via mosquitoes).
• Daily platelet monitoring — patients should return for a daily CBC if their platelet count is falling.

When to Hospitalise

Hospital admission is required if:

• Any warning signs are present (see above)
• Platelet count falls below 50 ×10⁹/L
• The patient cannot maintain adequate oral fluid intake
• Co-morbidities (pregnancy, diabetes, heart disease, elderly) increase risk

At A&B, hospitalised dengue patients receive IV fluid support (calculated carefully — both fluid deficiency and overload are dangerous in dengue), close monitoring of haematocrit (rising haematocrit indicates plasma leakage), platelet monitoring, and vital sign observation.

Platelet Transfusion

Platelet transfusion is not indicated simply because the platelet count is low. The threshold for prophylactic platelet transfusion is a count below 10 ×10⁹/L, or below 20–50 ×10⁹/L if the patient is actively bleeding or undergoing a procedure. Transfusing platelets at counts of 50–80 ×10⁹/L without active bleeding does not prevent bleeding and may cause harm.

How Do You Prevent Dengue in Pokhara?

Dengue prevention targets the Aedes aegypti and Aedes albopictus mosquitoes, which:

• Bite during the day (morning and late afternoon peaks)
• Breed in clean, stagnant water
• Live close to human habitation

Individual prevention:

• Apply DEET-based repellent during outdoor activities
• Wear long sleeves and trousers during peak biting hours
• Use mosquito nets if sleeping during the day (dengue mosquitoes do not primarily bite at night)

Community prevention (the most important):

• Empty flower pots, tyres, plant saucers, and any containers that hold stagnant water — weekly
• Cover water storage tanks with tight lids
• Ensure drains are clear and not pooling water
• Report stagnant water on community land to municipal services

There is currently no dengue vaccine approved or widely available in Nepal’s public health system. A dengue vaccine (Dengvaxia) exists but is indicated only for individuals with confirmed prior dengue infection — vaccination of dengue-naive individuals increases severe dengue risk.

Dengue Testing and Treatment at A&B International Hospital

A&B International Hospital

Pokhara-02, Bindhyaabasini Way to Sarangkot

Phone: +977 061-412512

NS1 antigen and dengue serology with same-day results. 24/7 emergency assessment for severe dengue warning signs. Experienced clinical team managing Pokhara’s annual dengue season. ECHS cashless care for entitled beneficiaries.