Experts warn transmission persists into colder months. Health experts have highlighted case clusters post-monsoon in areas with stagnant water, poor drainage, and low public awareness.
As the monsoon rains recede, health experts and government agencies are sounding the alarm: Nepal remains at high risk of dengue outbreaks in the post-monsoon period, despite fewer deaths so far. With nearly 6,000 infections reported in 2025 and the disease spreading into new areas, the warning comes at a critical juncture.
Dr. Sher Bahadur Pun, coordinator of the Research Unit at Sukraraj Tropical and Infectious Disease Hospital, Teku, has cautioned that although only “a few deaths” have occurred, the number of infections – 5,874 confirmed across 75 districts – should not be taken lightly. Two districts, Manang and Dolpa, remain free of reported cases thus far.
Provinces Hit Hard
The burden of infection is unevenly distributed:
- Gandaki Province leads with 1,502 confirmed cases.
- Bagmati follows with 1,380.
- Lumbini has reported 991 cases.
- Other provinces – Koshi, Sudurpaschim, Karnali, Madhesh – are also affected, though to a lesser extent.
To date, four deaths from dengue have been recorded during this monsoon season.
Risk Not Over as Winter Approaches
Experts emphasize that transmission may continue well into the colder months. Dr. Pun notes that clusters of cases tend to occur even after monsoon, particularly where environmental conditions remain favourable – stagnant water, poor drainage, and areas where public awareness is low. “Many people assume there is no longer a risk since the monsoon has ended,” he said, noting past outbreaks such as those in Dharan in 2019 and Syangja in 2022.
This caution is echoed in government warnings. Though the Ministry of Health has said the risk is diminishing as winter sets in, health officials and vector-control authorities are urging vigilance until at least mid-November and possibly even until the end of December, especially in localised “hotspot” clusters.
Climate, Altitudes, and Changing Patterns
The changing climate is a key factor in the shifting landscape of dengue risk. Nepal’s first dengue case was recorded only in 2004, but in the past two decades, the disease has become increasingly endemic. Major outbreaks are now almost annual during the monsoon season.
One of the notable trends is spread into hilly and mountainous regions. Dozens of mountain districts that were previously free or lightly affected have seen increasing numbers of cases. For example, mountain districts such as Gorkha, Sankhuwasabha, Bajhang, and Ramechhap are now reporting dengue infections, underscoring how elevation is no longer a shield.
Experts link this shift to several environmental changes: rising minimum temperatures, unpredictable and heavy rainfall, and sustained warm periods – all of which favour the breeding and survival of Aedes aegypti and Aedes albopictus, the mosquito vectors of dengue.
Under-Reporting and Asymptomatic Cases
Another challenge is the undercounting of dengue cases. Health authorities believe that a large proportion of infections go unreported due to mild or non-specific symptoms; many infected individuals do not present to health facilities.
The Epidemiology and Disease Control Division (EDCD) acknowledges gaps in surveillance and diagnostic coverage, particularly in remote and mountainous districts where health infrastructure is limited.
Prevention, Awareness, and Response
With an outbreak potentially looming, experts and official sources alike stress the importance of prevention and community engagement. Key recommendations include:
- Eliminating stagnant water sites (e.g., open water containers, discarded tyres, gutters).
- Strengthening vector control measures such as larval source management, fogging or spraying in hotspots.
- Raising public awareness about symptoms – high fever, severe body/joint pain, headache, loss of appetite, diarrhea, vomiting, skin rashes – and urging people to seek medical help early.
Health officials also call for preparedness in healthcare facilities, especially in hill and mountain areas, to manage severe cases. Winter weather should not lull stakeholders into complacency, Dr. Pun warns.
As Nepal moves further into the post-monsoon season, the health sector faces a precarious balance. On one side are the improving weather conditions and fading monsoon rains; on the other, the remnants of mosquito-friendly conditions – standing water, warm afternoons, high humidity – that sustain dengue transmission.
If history is any guide, localised outbreaks clustered around favourable ecological and environmental zones may emerge, possibly overwhelming under-resourced health units. Government agencies and local communities must stay alert, proactive, and coordinated to prevent what could otherwise become a serious public health problem even as winter approaches.
