Dengue in Nepal
If you are planning to go on a trek in Nepal, it is important to be aware of the recent proliferation of dengue in Kathmandu and Pokhara. While cases spike in the post-monsoon months in Autumn (October and November), the virus has become endemic and cases are reported all months of the year. October and November are the busiest months for trekking in Nepal and hence it is important to take the necessary steps to prevent getting infected during your visit.
History of Dengue in Nepal:
Those who grew up in Kathmandu in the 80’s and 90’s had never heard of Dengue. That’s because patient zero was identified only in 2004. A Japanese traveler had come to Nepal from India, after contracting the virus. Two years later, in 2006, 32 cases of Dengue were reported in Chitwan. Only in 2010, did Nepal experience its first-ever major outbreak with 917 cases and 5 deaths. The next big surge happened in 2013. By this time, the infection had spread to 25 different districts of Nepal. The dengue-causing mosquito that transmits the virus is more common in tropical and subtropical climates. But as temperatures rose, more dengue cases have been reported in hilly and mountainous parts of Nepal. In 2022, a total of 54,784 dengue cases were reported with 88 fatalities – the highest number reported till date. In 2024, at least 15 died and 41,865 others were infected by the deadly virus which spread to 76 districts.
Kathmandu has become an ideal breeding ground for the Aedes vector mosquito because of climate change, relentless and haphazard urbanisation, brisk trade and transit from dengue-infested areas, and poor health infrastructure, all conducive to the spread of dengue. The good news is that both epidemiologists and clinicians have been surprised to find that, even as the number of cases increases, the proportion of people getting severe infection is falling.
If interested, read article by GAVI, the vaccine alliance: In Nepal, climate change is shadowed by two decades of surging dengue
What months of the year is Dengue prevalent in Nepal:
While the post-monsoon months of October and November are considered dengue epidemic months, in 2025, over 800 people from 57 districts, including Kathmandu, Bhaktapur, and Lalitpur have tested positive for dengue. Monsoon begin in June and ends by September. This is when the mosquitoes breed in clean water and bite people in daylight. However, in recent years, as outbreaks are reported every month, including in the winter months, dengue has become endemic in Nepal.
What are the symptoms:
According to the WHO, most people with dengue have mild or no symptoms and will get better in 1–2 weeks. Rarely, dengue can be severe and lead to death. If symptoms occur, they usually begin 4–10 days after infection and last for 2–7 days. Symptoms may include:
- high fever (40°C/104°F)
- severe headache
- pain behind the eyes
- muscle and joint pains
- nausea
- vomiting
- swollen glands
- rash.
Individuals who are infected for the second time are at greater risk of severe dengue.
Severe dengue symptoms often come after the fever has gone away:
- severe abdominal pain
- persistent vomiting
- rapid breathing
- bleeding gums or nose
- fatigue
- restlessness
- blood in vomit or stool
- being very thirsty
- pale and cold skin
- feeling weak.
What causes dengue:
Dengue is a mosquito-borne viral disease transmitted by female Aedes aegypti also called the Egyptian Mosquito and Aedes albopictus mosquitoes. The same vectors also transmit chikungunya, yellow fever, and Zika viruses. Aedes aegypti can be recognized by black and white markings on its legs. This mosquito originated in Africa, but is now a common invasive species that has spread to tropical, subtropical, and temperate regions throughout the world. Aedes albopictus is a mosquito native to the tropical and subtropical areas of Southeast Asia. It too is characterized by the white bands on its legs and body.
Treatment:
There is no specific treatment for dengue. The focus is on treating pain symptoms. Most cases of dengue fever can be treated at home with pain medicine. Acetaminophen (paracetamol) is often used to control pain. Non-steroidal anti-inflammatory drugs like ibuprofen and aspirin are avoided as they can increase the risk of bleeding.
For people with severe dengue, hospitalization is often needed.
If you get dengue, it’s important to:
- rest;
- drink plenty of liquids;
- use acetaminophen (paracetamol) for pain;
- avoid non-steroidal anti-inflammatory drugs, like ibuprofen and aspirin; and
- watch for severe symptoms and contact your doctor as soon as possible if you notice any.
Prevention
The mosquitoes that spread dengue are active during the day (dawn to dusk). Lower the risk of getting dengue by protecting yourself from mosquito bites by using:
- clothes that cover as much of your body as possible. In October and November, wear pants (instead of shorts) and full sleeved shirts.
- mosquito nets if sleeping during the day, ideally nets sprayed with insect repellent;
- or turn on the air-conditioner in your room
- mosquito repellents: If buying in Nepal, Odomos cream is widely available.
- mosquito coils and vaporizers.
Mosquito breeding can be prevented by:
- preventing mosquitoes from accessing egg-laying habitats by environmental management and modification;
- disposing of solid waste properly and removing artificial man-made habitats that can hold water;
- covering, emptying and cleaning domestic water storage containers on a weekly basis;
- applying appropriate insecticides to outdoor water storage containers.
The first dengue fever vaccine (Dengvaxia) that was licensed for use in 20 countries around the world, was found to cause severe disease in persons with no prior immunity to dengue. WHO has recommended that it only be used in individuals after confirming prior dengue infection. Another dengue vaccine called Qdenga by Takeda can be used in all individuals without confirming prior dengue infection. This vaccine is currently approved in the European Union, UK and several countries across the globe. It has received WHO pre-qualification in May 2024. Both these vaccines are not available in Nepal at present.
