By: Ruby Maka Shrestha, Research Project Coordinator: Dhulikhel Hospital, Nepal || MPH The University of Sheffield
Dengue is a mosquito-borne disease emerging in Nepal in the form of Dengue Fever (DF), Dengue Hemorrhagic Fever (DHF), and Dengue Shock Syndrome (DSS). The earliest cases of Dengue were only detected back in 2004 in Nepal. However, the sporadic cases continued and outbreaks occurred several times over years most recently in 2019 with a total of 17,992 reported cases from 68 districts across seven provinces of Nepal. According to Epidemiology and Disease Control Division, as of 18 September, a total of 16,587 Dengue cases were reported, however, looking at the previous trend of dengue outbreaks, the current number is expected to spike up, considering the highest number of cases were reported on October and November. Is this the failure in Public Health Management in Nepal?
Dengue is a viral infection transmitted to humans through the bite of infected Aedes mosquitoes and caused by a virus of the Flaviviridae family. In Nepal, a total 4 sub-types (DEN-1, DEN-2, DEN-3 and DEN-4) of Dengue virus circulates. Dengue is commonly widespread throughout the tropics and sub-tropics around the world. In Nepal, although the initial cases were either reported from the terrain of terai or among patients who had a travel history of a neighboring country (India), indigenous cases are also increasing in a sub-tropic climate of hilly reasons including the capital city: Kathmandu. Recent data on Dengue Outbreak shows the highest outbreak of cases from the Bagmati Provinces, with the highest number of reported cases from Kathmandu, Lalitpur and Makwapur districts respectively.
Dengue was observed in 75 out of 77 districts in Nepal previously and endemic in all seven provinces, with total 16 confirmed deaths this year. The recent increase in the number of cases is attributed to the expansion of the vector Aedes aegypti and Aedes albopictus, as a result of the movement of people and the introduction of imported cases. Moreover, there is a high risk of widespread of dengue mosquitoes, particularly in high dense city like Kathmandu, — attributed to haphazard urbanization, improper waste management and unplanned housing.
Environmental conditions such as rain, temperature variation, and humidity are directly linked with vector growth. In Nepal, Dengue cases are primarily observed in between July to December with a spike rise in September to October and a decline in December – reaching the highest in number at the end of monsoon and post-monsoon season. Recent seasonal variation and increasing temperature of Kathmandu could also possibly be a favorable condition for the spread of disease by making it easier for mosquitoes to reproduce and replicate faster. In addition, lack of proper environmental sanitation and sewage management uncovered water bodies and high population density could have led to the rapid spread of infection. Kathmandu, along with other major cities has become an ideal breeding ground for mosquitoes due to warmer temperatures, an unusual pattern of rainfall, and relentless and haphazard urbanization. Moreover, Aedes mosquito fly only 500m, making it easier for mosquitoes to rapidly spread infection in a dense population.
What can be done?
Public Health Interventions are crucial, more than ever, to prevent the widespread of Dengue across the country. The relevant authority must initiate an effective prevention strategy to ensure the timely management of Dengue to prevent further outbreak of the disease. For now, it is essential to start with a short term strategy – creating awareness about the disease in the population via education program, mass-media campaign, and active case findings and treatment strategy. In long run, it is essential to conduct an active surveillance of the disease outbreak to understand the magnitude, and cause of disease in the country. The surveillance system will help us to understand the disease pattern and prepare for preventive measures ahead.
Like other countries around the world, Nepal to is experiencing the impact of climate change in the form of increased temperature, environmental hazards, and changes in disease patterns. With insufficient planning and the capacity of the federal government to intervene at the local level, prevention strategies have not been successfully implemented and followed at the local level. It is high time to strengthen the public health system of the country and create an active public health mechanism to prevent and mitigate the impact of climate-induced disease patterns in the country. The government body should take an active role in prevention of infectious diseases and take a serious concern on changing disease pattern in the country. A strong surveillance mechanism should be established with full capacity and authority to guide the nation with the establishment of prevention strategies at three tiers of the government health system structure. Moreover, it is crucial for us to collaborate with both public and private partners willing to provide expert services in case of emergencies and outbreaks.
2. Saud B, Adhikari S, Maharjan L, Paudel G, Amatya N, Amatya S. An epidemiological perspective of focal outbreak of dengue infection in Kathmandu, Nepal. J Clin Virol Plus. 2022 Feb 1;2(1):100063.