Mapping of vectors and eco-bio-social determinants under varying climatic conditions in Nepal.



Ongoing


January 1, 2023 to December 31, 2025


Nepal Health Research Council and Institute of Tropical medicine, Antwerp, Belgium


Eastern and Central Nepal


Vector borne diseases (VBDs) are a major public health concern in Nepal, affecting large population leading to significant morbidity and mortality. The country’s warm and humid climate, combined with poor sanitation, urbanization and lack of awareness make it a prime location for the spread of mosquito-borne diseases such as dengue, malaria, chikungunya etc. Similarly, Leishmaniasis is a parasitic infection caused by the parasite Leishmania spp and is transmitted by the bite of infected sandflies. These diseases pose a serious threat to the Nepalese population, particularly to those who live in rural areas where healthcare access is limited. The lack of effective vaccine against these diseases underscores the need for vector control measures to contain the spread of diseases in the meantime. There is increasing evidence about the impact of climate change on the distribution of VBDs. The future distribution of dengue vectors and the extent of dengue disease outbreaks will strongly depend on the extent and speed of the vector’s adaptation to altered thermal conditions. At their origin, the mosquitoes need to cope with rising temperatures due to global warming, whereas they have to adapt to colder temperatures at newly invaded regions, i.e. at higher altitudes and latitudes. Climate adaptation of the arboviral vectors will determine if dengue disease can persist and DENV can circulate in a given region that faces climatic changes. A better understanding of adaptive processes of both DENV vectors to thermal stress is urgently needed to estimate the future distribution of dengue virus. We aimed to conduct mixed method study. In quantitative study, Knowledge, attitude and practice survey was conducted among households’ members and entomological study was conducted to collect mosquitoes and sandflies vectors from Eastern and Central part of Nepal. Likewise, for qualitative survey, focus group discussion (FGD) was conducted among the community people, In-depth interview (IDI) among the household people and Key informant interview (KII) was conducted among focal persons of dengue till saturation was attained. Mapping the distribution of mosquito and sandfly vectors can help identify high-risk areas for disease transmission and can contribute to disease surveillance efforts by providing data on the geographical distribution.


General objective:

To map vectors, to explore eco-bio-social determinants for vector prevention and control measures in different eco-regions of Nepal and identify how the vectors are adapting to increasing temperatures driven by climate warming.

Specific Objectives:

  1. To ascertain the presence of different mosquitoes with a major focus on dengue vectors (sampling of eggs, larvae, pupae and adults) including their associated diseases (analysis of infections of vectors and epidemiological case data) prevailing in different altitudes in Nepal and investigate the impact of climate change (analysis climatic data from weather stations) on their occurrence in the present, compare the results to the past and predict changes for the future. 
  2. To assess people’s knowledge and attitude on dengue fever and its vector prevention and control practice at different altitudes (knowledge, attitude and practice – KAP). 
  3. To analyze eco-bio-social drivers for the practice and social acceptance of different preventive and control measures against dengue. Heat tolerance and adaptive potential of dengue vectors 
  4. To investigate the heat responsiveness of mosquitoes to understand the adaptation potential to climate warming (heat tolerance experiments) and interpolate gene/climate association (whole genome sequencing of vectors and genotype-environment association analysis) and extrapolate climate adaptation of the vector to geographically unstudied areas and future climates (genomic forecasting) in Nepal.
  5. To examine how locally achieved advancements in heat stress tolerance and eventually associated variance in vector competence become evolutionary anchored in invasive Aedes populations (Phenotype-based selection and introgression experiment).

This result will have at least three significant outcomes with a high potential for scientific impact: 1) It is the first case study on the triad of VBD-linked biodiversity, health and climate adaptation in a global hotspot of climate warming and regular VBD outbreaks. 2) The genomic forecasting of climate adaptation as a new approach to forecast the impact of climate change on invasive vectors. 3) Fundamental understanding of the extraordinary high phenotypic plasticity of two arboviral vectors with significant medical relevance around the globe.